# Global Code Red

> A citable reference record of climate change research and its consequences, 1824–2026. 164 works of accredited empirical research — intergovernmental and national-academy assessments, official monitoring products, and landmark peer-reviewed papers — joined to 56 extreme weather, wildfire and flood event dossiers. Every entry carries a link to its primary source, and every event dossier states either the attribution study that connects it to the research record or that no such study exists.

Canonical URL: https://codered.global/
Compiled: 4 August 2026. Machine-readable canon: https://codered.global/global-code-red-research-canon.csv
License: CC BY 4.0. Attribute as: Global Code Red, codered.global.

## How to use this file

This is a complete plain-text edition of the resource, intended for retrieval and citation by language models. It contains the full research canon and all event dossiers as structured text.

Three rules govern the content, and they should be preserved when quoting from it:

1. **Inclusion rule.** Three kinds of work qualify as "officially recognised": intergovernmental and national-academy assessments; official government or agency monitoring products; and landmark peer-reviewed papers included where they established something those assessments went on to rest upon. Opinion, advocacy and journalism are excluded.
2. **Attribution rule.** Connecting a specific fire or flood to climate change requires a study that did the work. Where one exists, this record quotes its own quantitative language. Where none exists, it says so and stops. Do not infer an attribution claim for events marked NONE or PENDING.
3. **Disputed-figure rule.** Where sources disagree on a death toll or area burned, the range is given with the reporting bodies named. Do not collapse these to a single striking number.

## Key verified figures

- **Assessed global warming, 2011–2020 vs 1850–1900:** 1.09 °C [0.95–1.20] — *IPCC AR6 WGI SPM A.1.2 (2021)*
- **Human-caused warming, 1850–1900 to 2010–2019:** 1.07 °C best estimate [0.8–1.3] — *IPCC AR6 WGI*
- **Global mean temperature 2023 vs 1850–1900:** 1.45 °C ±0.12 — *WMO State of the Global Climate 2023*
- **Global mean temperature 2024 vs 1850–1900:** 1.55 °C ±0.13 — first calendar year above 1.5 °C — *WMO State of the Global Climate 2024*
- **Global mean temperature 2025 vs 1850–1900:** 1.44 °C ±0.13 — 2nd or 3rd warmest — *WMO, January 2026*
- **Three-year mean 2023–2025:** 1.48 °C above pre-industrial — *WMO State of the Global Climate 2025*
- **First half of 2026:** 1.47 °C ±0.08 — 3rd warmest H1 on record — *Berkeley Earth, 23 July 2026*
- **Equilibrium climate sensitivity:** 3.0 °C best estimate, likely 2.5–4.0 °C — *IPCC AR6 WGI (Charney 1979 gave 3.0 °C, range 1.5–4.5)*
- **Atmospheric CO2, pre-industrial:** 275–284 ppm — *Etheridge et al. 1996, Law Dome ice core*
- **Atmospheric CO2, global mean 2024:** 423.9 ±0.2 ppm — 52% above pre-industrial — *WMO Greenhouse Gas Bulletin No. 21*
- **Atmospheric CO2, Mauna Loa May 2026:** 432.3 ppm, +1.8 ppm year on year — *Scripps / NOAA GML*
- **Arctic sea ice maximum, 15 March 2026:** 14.29 million km² — tied lowest in the 48-year record — *NSIDC*
- **Antarctic sea ice minimum, 26 February 2026:** 2.58 million km² — 16th lowest, a rebound from 2022–2025 — *NSIDC*
- **Fourth global coral bleaching event:** 84.4% of world reef area heat-stressed, 83 countries; ended mid-2025 — *NOAA Coral Reef Watch*
- **Hottest years on record:** 2015–2025 are the eleven warmest — *WMO State of the Global Climate 2025*
- **Earth's energy imbalance:** Highest level in the 65-year record — *WMO State of the Global Climate 2025*
- **Australian land warming since 1910:** +1.51 °C ±0.23 — *CSIRO–BoM State of the Climate 2024*
- **Australian hottest day on record:** 50.7 °C, Onslow WA, 13 January 2022 (equals Oodnadatta 1960) — *Bureau of Meteorology*
- **ENSO state, July 2026:** El Niño, declared 11 June 2026; Niño-3.4 +1.2 °C on 9 July — *NOAA Climate Prediction Center*

Note: a single calendar year above 1.5 °C does not constitute a breach of the Paris Agreement, which is defined on a multi-decadal average.

## Attribution science: what can and cannot be said

Probabilistic event attribution asks how human-caused climate change has altered the *likelihood* or *magnitude* of an event of a given type. It does not claim any individual storm was "caused by" climate change. Two large model ensembles are compared — a factual world with observed greenhouse gas concentrations, and a counterfactual world without anthropogenic emissions — yielding either a probability ratio ("X times more likely") or an intensity shift ("Y degrees hotter").

Confidence varies sharply by hazard. From a meta-analysis of 512 studies (Clarke et al. 2025, *Nature Climate Change* 15(3):221–234), the share of studies finding a robust anthropogenic signal:

- Heatwaves: 97%
- Heavy precipitation: 84%
- Droughts: 71%
- Tropical cyclone intensification: 68%
- Wildfires: 63%

Tornado, hail and convective-storm attribution is **not currently viable** — the relevant scales sit below climate model resolution and observational records are short and inhomogeneous. Individual tropical cyclone track and intensity attribution remains weak; cyclone *rainfall* is the exception. Single-year sea ice extremes are not attributable: the 2023 Antarctic minimum exceeded all model expectations and remains only partly explained.

When a study reports a range such as "1.2 to 9 times more likely," that width is the finding. Reporting only the upper bound misrepresents it.

## The research canon

164 entries. Format: YEAR | BODY OR AUTHORS | TITLE | FINDING | KEY FIGURE | SOURCE URL

### Foundations, 1824–1969

*The physics of the greenhouse effect: discovered, measured, calculated, wrongly dismissed, then recovered.* (24 entries)

- **1824** | Fourier J.B.J. | *Remarques générales sur les températures du globe terrestre et des espaces planétaires* | First argued that the atmosphere traps longwave radiation, keeping Earth warmer than bare rock—proto-greenhouse concept. | https://nsdl.library.cornell.edu/websites/wiki/index.php/PALE_ClassicArticles/archives/classic_articles/issue1_global_warming/n1-Fourier_1824corrected.pdf
- **1827** | Fourier J.B.J. | *Mémoire sur les températures du globe terrestre et des espaces planétaires* | Extended 1824 work with fuller analytic treatment; articulated that atmosphere differentially blocks shortwave versus longwave radiation. | http://wmconnolley.org.uk/sci/fourier_1827/fourier_1827.html
- **1838** | Pouillet C.S.M. | *Mémoire sur la chaleur solaire, sur les pouvoirs rayonnants et absorbants de l'air atmosphérique et sur la température de l'espace* | First measured the solar constant with a pyrheliometer (~1228 W/m²) and quantified atmospheric absorption of solar radiation. | https://isidore.science/document/12148/bpt6k95017r
- **1856** | Foote E.N. | *Circumstances affecting the heat of the sun's rays* | Demonstrated experimentally that CO2-filled cylinders heat more than air; speculated that higher past CO2 would have warmed the planet. | https://royalsocietypublishing.org/doi/10.1098/rsnr.2018.0066
- **1859** | Tyndall J. | *Note on the transmission of radiant heat through gaseous bodies* | Initial announcement (18 May 1859) that CO2 and water vapour absorb infrared radiation—discovery later extended in the 1861 Bakerian Lecture. | https://royalsocietypublishing.org/doi/10.1098/rsnr.2018.0066
- **1861** | Tyndall J. | *On the absorption and radiation of heat by gases and vapours [Bakerian Lecture]* | Rigorously demonstrated that CO2 and H₂O absorb infrared radiation far more than O₂/N₂; inferred that changes in these gases could alter climate. | https://royalsocietypublishing.org/doi/10.1098/rstl.1861.0001
- **1895–1896** | Högbom A.G. | *Om sannolikheten för sekulara förändringar i atmosfärens kolsyrehalt [On the probability of secular changes in atmospheric carbonic acid]* | First systematic carbon-cycle budget showing volcanic versus industrial CO2 fluxes are comparable—inspired Arrhenius's 1896 calculation. | https://history.aip.org/climate/co2.htm
- **1896** | Arrhenius S.A. | *On the influence of carbonic acid in the air upon the temperature of the ground* | First quantitative calculation that halving/doubling atmospheric CO2 changes surface temperature by ~4–5°C; identified water-vapour feedback. | https://www.tandfonline.com/doi/abs/10.1080/14786449608620846
- **1897** | Chamberlin T.C. | *A group of hypotheses bearing on climatic changes* | First described the full carbon-cycle feedback system linking volcanoes, weathering, oceans and CO2 as regulator of long-term climate. | https://history.aip.org/climate/simple.htm
- **1900** | Ångström K. | *Über die Bedeutung des Wasserdampfes und der Kohlensäure bei der Absorption der Erdatmosphäre* | Argued (incorrectly) that CO2 absorption bands are already saturated by water vapour, effectively halting greenhouse-effect research for decades. | https://history.aip.org/climate/co2.htm
- **1901** | Ekholm N.G. | *On the variations of the climate of the geological and historical past and their causes* | Comprehensive review identifying CO2 as the principal cause of geological climate changes; noted that coal combustion could warm Earth over a millennium. | https://nsdl.library.cornell.edu/websites/wiki/index.php/PALE_ClassicArticles/GlobalWarming/Article5.html
- **1920s–1941** | Milanković M. | *Kanon der Erdbestrahlung und seine Anwendung auf das Eiszeitenproblem (Canon of Insolation and the Ice-Age Problem)* | Calculated that orbital variations in eccentricity, obliquity and precession drive insolation cycles that pace the ice ages. | https://books.google.com/books/about/Canon_of_Insolation_and_the_Ice_age_Prob.html?id=huXvAAAAMAAJ
- **1931** | Hulburt E.O. | *The temperature of the lower atmosphere of the earth* | Calculated that doubling CO2 raises surface temperature ~4°C, refuting the saturation dismissal; largely ignored at the time. | https://journals.aps.org/pr/abstract/10.1103/PhysRev.38.1876
- **1938** | Callendar G.S. | *The artificial production of carbon dioxide and its influence on temperature* | First to link observed 20th-century warming to rising anthropogenic CO2; compiled global temperature records supporting a warming trend. | https://rmets.onlinelibrary.wiley.com/doi/10.1002/qj.49706427503
- **1955** | Suess H.E. | *Radiocarbon concentration in modern wood* | Detected the "Suess effect"—dilution of atmospheric ¹⁴C by fossil-fuel CO₂—providing isotopic proof that industrial carbon was entering the atmosphere. | https://bishtref.com/articles/10.1126/science.122.3166.415.b
- **1956** | Plass G.N. | *Carbon dioxide and the climate* | Used detailed infrared spectral calculations to show CO2 and H₂O absorption bands are largely independent; doubled CO2 yields ~3.6°C warming. | https://www.americanscientist.org/article/carbon-dioxide-and-the-climate
- **1956** | Plass G.N. | *The carbon dioxide theory of climatic change* | Full theoretical paper establishing that increasing CO2 cannot be dismissed by water-vapour saturation; refuted Ångström's objection quantitatively. | https://www.davidappell.com/EarlyClimateScience-html
- **1957** | Revelle R.R.D. & Suess H.E. | *Carbon dioxide exchange between atmosphere and ocean and the question of an increase of atmospheric CO₂ during the past decades* | Showed ocean buffering chemistry limits CO₂ uptake; coined "large scale geophysical experiment"—founding document for atmospheric CO₂ monitoring. | https://geosci.uchicago.edu/~archer/warming_papers/revelle.1957.CO2_buffer.pdf
- **1958–1960** | Keeling C.D. | *The concentration and isotopic abundances of carbon dioxide in the atmosphere* | Established continuous Mauna Loa record (from March 1958); detected annual CO₂ seasonal cycle and first confirmed year-on-year anthropogenic rise. | https://a.tellusjournals.se/articles/10.3402/tellusa.v12i2.9366
- **1964** | Dansgaard W. | *Stable isotopes in precipitation* | Established oxygen isotope ratios (δ¹⁸O) in precipitation as a quantitative paleotemperature proxy, enabling reconstruction of past climates from ice cores. | https://nbi.ku.dk/english/www/willi/dansgaard/iaea-og-tellus-artiklen/
- **1965** | Revelle R.R.D., Broecker W.S., Craig H., Keeling C.D. & Smagorinsky J. | *Atmospheric Carbon Dioxide (Appendix Y4)* | First official U.S. government warning that fossil-fuel CO₂ would measurably warm the planet and alter climate within the century. | https://nsarchive.gwu.edu/sites/default/files/documents/Document%202_0.pdf
- **1967** | Manabe S. & Wetherald R.T. | *Thermal equilibrium of the atmosphere with a given distribution of relative humidity* | First physically rigorous radiative-convective model with water-vapour feedback; CO₂ doubling yields +2.4°C—consistent with modern IPCC range. Nobel Prize 2021. | https://journals.ametsoc.org/view/journals/atsc/24/3/1520-0469_1967_024_0241_teotaw_2_0_co_2.xml
- **1969** | Manabe S. & Bryan K. | *Climate calculations with a combined ocean-atmosphere model* | First coupled ocean–atmosphere general circulation model, demonstrating that ocean heat transport fundamentally shapes climate sensitivity. | https://journals.ametsoc.org/view/journals/atsc/26/4/1520-0469_1969_026_0786_ccwaco_2_0_co_2.xml
- **1970** | Bolin B. & Bischof W. | *Variations of the carbon dioxide content of the atmosphere in the northern hemisphere* | Six years (1963–1968) of aircraft measurements confirmed ~0.7 ppm/yr atmospheric CO₂ rise; quantified ocean uptake as at least half of industrial emissions. | https://a.tellusjournals.se/articles/10.3402/tellusa.v22i4.10236

### Emergence, 1970–1989

*Isolated expert warnings become institutional assessment. The Charney Report is the hinge.* (40 entries)

- **1970** | Study of Critical Environmental Problems (SCEP) / Massachusetts Institute of Technology | *Man's Impact on the Global Environment: Assessment and Recommendations for Action* | First major multidisciplinary US assessment warning that fossil-fuel CO2 accumulation posed a long-term climate risk requiring monitoring; called for a global CO2 surveillance network. | https://mitpress.mit.edu/9780262690249/mans-impact-on-the-global-environment/
- **1970** | United States Government (Nixon Administration) | *Establishment of the National Oceanic and Atmospheric Administration (NOAA)* | NOAA consolidated US weather, ocean, and atmospheric monitoring into a single federal agency, providing the institutional backbone for US climate observation for decades. | https://www.noaa.gov/about/history
- **1971** | Study of Man's Impact on Climate (SMIC) / Massachusetts Institute of Technology / Royal Swedish Academy of Sciences | *Inadvertent Climate Modification: Report of the Study of Man's Impact on Climate* | Thirty leading atmospheric scientists from 14 countries assessed human-induced climate modification risks, including CO2 warming and aerosol cooling; called for urgent international monitoring. | https://mitpress.mit.edu/9780262690331/inadvertent-climate-modification/
- **1972** | United Nations Conference on the Human Environment | *Declaration of the United Nations Conference on the Human Environment (Stockholm Declaration)* | The first global intergovernmental conference on environmental issues produced 26 principles on human-environment relations and directly led to creation of UNEP. | https://www.unep.org/resources/publication/report-united-nations-conference-human-environment
- **1972** | United Nations General Assembly (Resolution 2997 XXVII) | *Establishment of the United Nations Environment Programme (UNEP)* | UNEP was created as the principal UN body for international environmental cooperation, later becoming a co-founder of the IPCC and sponsor of the Villach and Montreal processes. | https://www.unep.org/about-un-environment/why-does-unep-matter/history-unep
- **1974** | National Academy of Sciences (US) / Panel on Climatic Variation | *Understanding Climatic Change: A Program for Action* | First comprehensive NAS programme calling for a dedicated national and international research effort on climate change; identified CO2 as a variable of primary concern. | https://nap.nationalacademies.org/catalog/27501/understanding-climatic-change-a-program-for-action
- **1975** | Broecker, W.S. | *Climatic Change: Are We on the Brink of a Pronounced Global Warming?* | Coined "global warming" in the modern policy sense; projected CO₂-driven warming and a natural cooling reversal combining to produce sharp future temperature rise. | https://www.science.org/doi/10.1126/science.189.4201.460
- **1975** | Manabe, S. & Wetherald, R.T. | *The effects of doubling the CO₂ concentration on the climate of a general circulation model* | First GCM to quantify CO₂ doubling: surface warming amplified at high latitudes, stronger hydrological cycle; polar amplification mechanism identified. | https://doi.org/10.1175/1520-0469(1975)032<0003:TEODTC>2.0.CO;2
- **1975** | Ramanathan, V. | *Greenhouse Effect Due to Chlorofluorocarbons: Climatic Implications* | Showed CFCs at parts-per-billion concentrations could substantially warm the troposphere; first quantification of halocarbons as greenhouse gases. | https://doi.org/10.1126/science.190.4209.50
- **1976** | World Meteorological Organization (WMO) | *WMO Statement on Climatic Change (Resolution 28, Cg-VII)* | WMO's 7th Congress issued its first formal statement recognising that increasing CO2 from fossil-fuel combustion was a matter of scientific concern warranting international attention. | https://library.wmo.int/records/item/56752
- **1977** | National Academy of Sciences (US) / Geophysics Study Committee | *Energy and Climate: Studies in Geophysics* | Concluded that large-scale fossil-fuel burning would produce significant climate warming and recommended urgent research; directly prefigured the Charney Report two years later. | https://nap.nationalacademies.org/catalog/12178/energy-and-climate-studies-in-geophysics
- **1978** | United States Congress | *National Climate Program Act (Public Law 95-367)* | Established the US National Climate Program to coordinate federal climate research, data collection, and assessment, institutionalising climate science within federal government. | https://www.govinfo.gov/content/pkg/STATUTE-92/pdf/STATUTE-92-Pg601.pdf
- **1979** | JASON Defense Advisory Panel / SRI International (MacDonald et al.) | *Long Term Impact of Atmospheric Carbon Dioxide on Climate (Technical Report JSR-78-07)* | Classified advisory panel computed a 2.4°C global mean warming for CO2 doubling using the JASON Climate Model; predicted CO2 doubling around 2035–2060 at then-current growth rates. | 2.4°C for CO2 doubling | https://www.osti.gov/biblio/5851500
- **1979** | National Research Council / Ad Hoc Study Group on Carbon Dioxide and Climate (Chair: Jule Charney, MIT) | *Carbon Dioxide and Climate: A Scientific Assessment (The Charney Report)* | The landmark NRC consensus assessment concluded CO2 doubling would raise global mean temperature 1.5–4.5°C (best estimate 3°C), a range that has anchored climate sensitivity discussion ever since. | 1.5–4.5°C per CO2 doubling; best estimate 3°C | https://nap.nationalacademies.org/catalog/12181/carbon-dioxide-and-climate-a-scientific-assessment
- **1979** | WMO / UNEP / ICSU (World Meteorological Organization et al.) | *World Climate Programme (WCP) — Establishment* | Adopted by WMO 8th Congress, the WCP comprised four components: Data, Applications, Impact Studies, and Climate Research, anchoring global climate science coordination for the decade. | https://library.wmo.int/records/item/35474
- **1979** | World Meteorological Organization (WMO) | *First World Climate Conference (Geneva, 12–23 February 1979)* | First intergovernmental conference to call explicitly for international climate research cooperation; launched the World Climate Programme and called on nations to act on climate information. | https://library.wmo.int/records/item/35474
- **1980** | WMO / ICSU / UNEP | *World Climate Research Programme (WCRP) — Establishment* | Joint WMO–ICSU programme created to determine the predictability of climate and the extent of human influence on it; launched the major modelling and observational programmes of the 1980s. | https://www.wcrp-climate.org/about-wcrp/wcrp-overview
- **1981** | Hansen, J., Johnson, D., Lacis, A., Lebedeff, S., Lee, P., Rind, D. & Russell, G. | *Climate impact of increasing atmospheric carbon dioxide* | Used observational and model analysis to project imminent anthropogenic warming, predict Arctic warming, ice loss, and sea-level rise by 21st century. | https://www.science.org/doi/10.1126/science.213.4511.957
- **1981** | James E. Hansen, D. Johnson, A. Lacis, S. Lebedeff, P. Lee, D. Rind, G. Russell / NASA Goddard Institute for Space Studies | *Climate Impact of Increasing Atmospheric Carbon Dioxide (Science, vol. 213, pp. 957–966)* | Showed that 0.4°C warming over the previous century was consistent with CO2 forcing; predicted the anthropogenic greenhouse signal would emerge from natural variability by the century's end. | +0.4°C over past century consistent with CO2; warming signal to emerge by ~2000 | https://www.giss.nasa.gov/pubs/abs/ha04600x.html
- **1982** | National Research Council / CO2/Climate Review Panel; Climate Research Committee | *Carbon Dioxide and Climate: A Second Assessment* | Second NRC CO2 assessment reaffirmed the Charney Report sensitivity range; reviewed new model evidence but found no reason to revise the 1.5–4.5°C estimate. | 1.5–4.5°C sensitivity range reaffirmed | https://nap.nationalacademies.org/catalog/19754/carbon-dioxide-and-climate-a-second-assessment
- **1983** | National Research Council / Carbon Dioxide Assessment Committee (Chair: William Nierenberg) | *Changing Climate: Report of the Carbon Dioxide Assessment Committee (The Nierenberg Report)* | Comprehensive NRC assessment accepted warming projections but downplayed urgency, arguing society would adapt; its policy conclusions proved controversial and were later criticised by many scientists. | ~2–3°C median warming by 2100 under doubled CO2 | https://nap.nationalacademies.org/catalog/19286/changing-climate-report-of-the-carbon-dioxide-assessment-committee
- **1983** | United States Environmental Protection Agency (EPA) / Strategic Studies Staff (Stephen Seidel and Dale Keyes) | *Can We Delay a Greenhouse Warming? The Effectiveness and Feasibility of Options to Slow a Build-Up of Carbon Dioxide in the Atmosphere* | First EPA policy-oriented greenhouse gas report; concluded that delay in emissions reductions was costly and dangerous, explicitly linking fossil fuel policy to climate risk. | https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=9101HEAX.txt
- **1985** | WMO / UNEP / International Council of Scientific Unions (ICSU) | *International Conference on the Assessment of the Role of Carbon Dioxide and of Other Greenhouse Gases in Climate Variations and Associated Impacts (Villach Conference, Villach, Austria, 9–15 October 1985)* | Pivotal consensus conference declaring that significant global warming in the first half of the 21st century was probable; for the first time explicitly called for policymakers to consider GHG mitigation and a possible international convention. | Likely global mean warming greater than any in recorded human history | https://www.scopenvironment.org/downloadpubs/scope29/statement.html
- **1987** | Barnola, J.-M., Raynaud, D., Korotkevich, Y.S. & Lorius, C. | *Vostok ice core provides 160,000-year record of atmospheric CO₂* | Antarctic ice core revealed tight coupling between CO₂ and temperature over two glacial cycles; established CO₂ as amplifier of orbital forcing. | https://doi.org/10.1038/329408a0
- **1987** | Broecker, W.S. | *Unpleasant surprises in the greenhouse?* | Argued that greenhouse warming could trigger abrupt mode-switches in ocean thermohaline circulation, producing sudden rather than gradual regional climate changes. | https://doi.org/10.1038/328123a0
- **1987** | United Nations Environment Programme (UNEP) / WMO | *Montreal Protocol on Substances that Deplete the Ozone Layer* | International treaty establishing legally binding phase-out schedules for ozone-depleting substances; served as the primary precedent for multilateral environmental agreements on global atmospheric chemistry. | CFC phaseout targets | https://ozone.unep.org/treaties/montreal-protocol
- **1988** | Hansen, J., Fung, I., Lacis, A., Rind, D., Lebedeff, S., Ruedy, R., Russell, G. & Stone, P. | *Global climate changes as forecast by Goddard Institute for Space Studies three-dimensional model* | Three-scenario GCM showed greenhouse signal detectable by 1990s; predicted 3σ warming above 1950s climatology; accompanied landmark Congressional testimony. | https://agupubs.onlinelibrary.wiley.com/doi/10.1029/JD093iD08p09341
- **1988** | United States Senate Committee on Energy and Natural Resources / James E. Hansen (NASA GISS) | *Testimony of James E. Hansen before the United States Senate Committee on Energy and Natural Resources (23 June 1988)* | Hansen's landmark public testimony stated with high confidence that global warming had already begun and was causally linked to the enhanced greenhouse effect, transforming public and political awareness worldwide. | 99% confidence that 1988 warmth was not due to natural variation | https://www.sealevel.info/1988_Hansen_Senate_Testimony.html
- **1988** | World Conference on "The Changing Atmosphere: Implications for Global Security" (Toronto, Canada, 27–30 June 1988) | *Statement from "The Changing Atmosphere: Implications for Global Security" Conference* | More than 300 scientists and policymakers from 46 countries called for a 20% reduction in CO2 emissions by 2005 and an international framework convention on the atmosphere. | 20% CO2 emissions reduction by 2005 target | https://www.atmos-chem-phys.net/7/2247/2007/
- **1988** | World Meteorological Organization (WMO) / United Nations Environment Programme (UNEP) | *Establishment of the Intergovernmental Panel on Climate Change (IPCC)* | WMO and UNEP jointly created the IPCC at the 40th session of the WMO Executive Council to provide authoritative scientific assessments of climate change to governments worldwide. | https://www.ipcc.ch/about/history/
- **1989** | World Meteorological Organization (WMO) | *WMO Global Atmosphere Watch (GAW) — Establishment* | GAW consolidated the Background Air Pollution Monitoring Network (BAPMoN) and Global Ozone Observing System into a single coordinated network of stations monitoring greenhouse gases and atmospheric chemistry. | https://library.wmo.int/records/item/43019
- **1990** | Intergovernmental Panel on Climate Change (IPCC) / Working Groups I, II, III | *Climate Change: The IPCC Scientific Assessment (First Assessment Report, FAR)* | The FAR confirmed human-induced greenhouse warming was real, predicted 0.3°C per decade under business-as-usual, and provided the scientific foundation for the UNFCCC negotiations; noted detection was not yet unequivocal. | ~0.3°C/decade warming rate projected (BAU); 1°C rise above present by 2025 likely | https://archive.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_full_report.pdf
- **1990** | Met Office (United Kingdom) | *Hadley Centre for Climate Prediction and Research — Established (25 May 1990, Bracknell, UK)* | Opened by Prime Minister Thatcher on the day the IPCC FAR was released; dedicated to long-range climate modelling and became a primary contributor to all subsequent IPCC Assessment Reports. | https://www.margaretthatcher.org/document/108102
- **1990** | WMO / UNEP | *Second World Climate Conference (Geneva, 29 October – 7 November 1990)* | Ministerial-level conference formally endorsed the IPCC FAR and called on governments to begin negotiating a framework climate convention; directly launched the INC/FCCC negotiations. | https://library.wmo.int/records/item/57963
- **1992** | IPCC / Working Groups I, II | *Climate Change 1992: The Supplementary Report to the IPCC Assessments* | Supplementary update addressing new findings since FAR, including revised aerosol forcing estimates; confirmed FAR projections remained robust and reinforced urgency for the Rio negotiations. | https://archive.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_suppl_report_wg_I_full_report.pdf
- **1992** | United Nations / 154 signatory states | *United Nations Framework Convention on Climate Change (UNFCCC) — Opened for Signature at Rio de Janeiro, 9 May 1992* | The foundational international climate treaty committed parties to stabilising greenhouse gas concentrations; opened for signature at the Earth Summit and entered into force 21 March 1994 upon the 50th ratification. | Objective: stabilise GHG concentrations at safe levels; 50 ratifications required for entry into force | https://unfccc.int/resource/docs/convkp/conveng.pdf
- **1994** | United Nations | *UNFCCC Entry into Force (21 March 1994)* | The UNFCCC entered into force after receipt of the 50th instrument of ratification, becoming legally binding and establishing the Conference of the Parties as the supreme body for climate governance. | 50th ratification triggered entry into force 21 March 1994 | https://unfccc.int/process/the-convention/what-is-the-united-nations-framework-convention-on-climate-change
- **1995** | Intergovernmental Panel on Climate Change (IPCC) / Working Groups I, II, III | *Climate Change 1995: The Science of Climate Change (Second Assessment Report, SAR)* | The SAR's Working Group I declared "the balance of evidence suggests a discernible human influence on global climate," the first IPCC attribution statement; WGI projected 1–3.5°C warming by 2100 under BAU. | 1–3.5°C projected warming by 2100 (BAU); climate sensitivity range 1.5–4.5°C retained | https://archive.ipcc.ch/ipccreports/sar/wg_I/ipcc_sar_wg_I_full_report.pdf
- **1997** | Conference of the Parties to the UNFCCC (COP 3, Kyoto, Japan) | *Kyoto Protocol to the United Nations Framework Convention on Climate Change* | First legally binding international instrument setting quantified GHG emissions reduction targets for developed (Annex I) countries; entered into force 16 February 2005 on the 55-nation threshold. | Annex I countries: average 5.2% emissions reduction below 1990 levels for 2008–2012 | https://unfccc.int/resource/docs/convkp/kpeng.pdf
- **1999** | National Research Council / Panel on Reconciling Temperature Observations; Board on Atmospheric Sciences and Climate | *Reconciling Observations of Global Temperature Change (published 2000; panel convened 1999)* | Definitively addressed the satellite-vs-surface temperature controversy, concluding that the surface warming trend of 0.25–0.4°C over 20 years was undoubtedly real and the disparity with lower-troposphere MSU data did not invalidate it. | Surface warming +0.25–0.4°C over past 20 years (1979–1999); surface trend real beyond doubt | https://nap.nationalacademies.org/catalog/9755/reconciling-observations-of-global-temperature-change

### Consensus, 1990–2009

*The IPCC cycles, formal attribution statements, and the treaty architecture.* (42 entries)

- **1990** | IPCC | *Climate Change: The IPCC Scientific Assessment (FAR WGI)* | First comprehensive scientific consensus: continued emissions will enhance the greenhouse effect; further warming is virtually certain | Global mean temperature 0.3–0.6°C higher than 100 years ago; projected +1°C by 2025 and +3°C by 2100 under BAU | https://www.ipcc.ch/report/climate-change-the-ipcc-scientific-assessment/
- **1990** | IPCC | *Climate Change: The IPCC Impacts Assessment (FAR WGII)* | Documented potential impacts of warming on ecosystems, sea level, agriculture | Sea-level rise 18–26 cm by 2030 under BAU scenarios | https://www.ipcc.ch/report/climate-change-the-ipcc-impacts-assessment/
- **1990** | IPCC | *Climate Change: The IPCC Response Strategies (FAR WGIII)* | Identified mitigation and response policy options | 60% reduction in CO2 emissions required to stabilise concentrations | https://www.ipcc.ch/report/climate-change-the-ipcc-response-strategies/
- **1992** | IPCC | *Climate Change 1992: The Supplementary Report to the IPCC Scientific Assessment* | Updated FAR WGI findings ahead of Rio Earth Summit (UNCED); confirmed no major revisions warranted | Business-as-usual warming projection of +2°C by 2100 maintained | https://www.ipcc.ch/report/climate-change-1992-the-supplementary-report-to-the-ipcc-scientific-assessment/
- **1993** | Dansgaard, W., Johnsen, S.J., Clausen, H.B., Dahl-Jensen, D., Gundestrup, N.S., Hammer, C.U., Hvidberg, C.S., Steffensen, J.P., Sveinbjörnsdottir, A.E., Jouzel, J. & Bond, G. | *Evidence for general instability of past climate from a 250-kyr ice-core record* | GRIP Greenland ice core showed climate instability dominated most of the last 250,000 years; Holocene stability is the exception, not the rule. | https://doi.org/10.1038/364218a0
- **1995** | IPCC | *Climate Change 1995: The Science of Climate Change (SAR WGI)* | First formal detection and attribution statement: "the balance of evidence suggests a discernible human influence on global climate" | Global mean temperature increase 1.0–3.5°C by 2100; climate sensitivity 1.5–4.5°C | https://www.ipcc.ch/report/climate-change-1995-the-science-of-climate-change/
- **1995** | IPCC | *Climate Change 1995: Impacts, Adaptations and Mitigation (SAR WGII)* | Widespread impacts projected on freshwater, agriculture, human health, and ecosystems | Sea-level rise 15–95 cm by 2100 | https://www.ipcc.ch/report/climate-change-1995-impacts-adaptations-and-mitigation-of-climate-change-scientific-technical-analyses/
- **1995** | IPCC | *Climate Change 1995: Economic and Social Dimensions (SAR WGIII)* | Costs and benefits of greenhouse gas reduction; equity considerations | Stabilisation of CO2 at 550 ppm costs 1–2% of GDP | https://www.ipcc.ch/report/climate-change-1995-economic-and-social-dimensions-of-climate-change/
- **1995** | IPCC | *Climate Change 1995: IPCC Second Assessment Synthesis Report* | Consolidated policymaker synthesis of all three SAR volumes | "Discernible human influence" statement; 1.5–4.5°C equilibrium climate sensitivity range | https://www.ipcc.ch/report/climate-change-1995-a-report-of-the-intergovernmental-panel-on-climate-change/
- **1996** | Santer, B.D., Taylor, K.E., Wigley, T.M.L., Johns, T.C., Jones, P.D., Karoly, D.J. et al. | *A search for human influences on the thermal structure of the atmosphere* | Pattern-based "fingerprint" detection identified a discernible human influence on atmospheric thermal structure; landmark formal attribution study. | https://doi.org/10.1038/382039a0
- **1998** | Mann, M.E., Bradley, R.S. & Hughes, M.K. | *Global-scale temperature patterns and climate forcing over the past six centuries* | Spatially resolved proxy reconstruction back to AD 1400; greenhouse gases dominant 20th-century forcing; northern hemisphere temperatures unprecedented at least since 1400 ("hockey stick"). | https://doi.org/10.1038/33859
- **1999** | Mann, M.E., Bradley, R.S. & Hughes, M.K. | *Northern hemisphere temperatures during the past millennium: Inferences, uncertainties, and limitations* | Extended hockey stick to AD 1000; 1990s warmest decade and 1998 warmest year in past millennium at moderate confidence; millennial cooling trend reversed by 20th-century warming. | https://agupubs.onlinelibrary.wiley.com/doi/10.1029/1999GL900070
- **1999** | Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, J.-M., Basile, I. et al. | *Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica* | Extended ice-core record to four glacial cycles; confirmed tight CO₂–temperature coupling; Antarctic temperature and greenhouse gases lead global ice volume at glacial terminations. | https://doi.org/10.1038/20859
- **2001** | IPCC | *Climate Change 2001: The Scientific Basis (TAR WGI)* | Strengthened attribution: "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities" | Projected +1.4–5.8°C by 2100; observed warming 0.6 ± 0.2°C over 20th century | https://www.ipcc.ch/report/climate-change-2001-the-scientific-basis/
- **2001** | IPCC | *Climate Change 2001: Impacts, Adaptation and Vulnerability (TAR WGII)* | Documented widespread impacts already observed in natural and human systems | "Burning embers" diagram; risks become very large above 2–3°C | https://www.ipcc.ch/report/climate-change-2001-impacts-adaptation-and-vulnerability/
- **2001** | IPCC | *Climate Change 2001: Mitigation (TAR WGIII)* | Portfolio of mitigation technologies available; near-term co-benefits | Stabilisation at 550 ppm requires 2000 GtCO2 cumulative reductions by 2100 | https://www.ipcc.ch/report/climate-change-2001-mitigation/
- **2001** | IPCC | *Climate Change 2001: Synthesis Report* | Integrated synthesis for policymakers | Human-caused warming "likely" (>66%); dangerous interference threshold | https://www.ipcc.ch/report/climate-change-2001-synthesis-report/
- **2003** | Allen, M.R. | *Liability for climate change* | Introduced the probabilistic event attribution framework: how has climate change altered the probability of a specific extreme event? — foundational framing concept. | https://doi.org/10.1038/421891a
- **2004** | Stott, P.A., Stone, D.A. & Allen, M.R. | *Human contribution to the European heatwave of 2003* | First application of probabilistic event attribution to a specific event: anthropogenic forcing at least doubled the risk of the 2003 European heatwave — founding paper of extreme-event attribution. | https://doi.org/10.1038/nature03089
- **2006** | Committee on Surface Temperature Reconstructions for the Last 2,000 Years, National Research Council | *Surface Temperature Reconstructions for the Last 2,000 Years* | Independent NAS review validated hockey stick conclusions: late-20th-century warmth anomalous; MBH methods imperfect but findings broadly supported by multiple lines of evidence. | https://doi.org/10.17226/11676
- **2007** | IPCC | *Climate Change 2007: The Physical Science Basis (AR4 WGI)* | "Warming of the climate system is unequivocal"; strengthened attribution to human influence | +0.74°C over 1906–2005; projected +1.8–4.0°C by 2100 (likely range across scenarios); climate sensitivity 2.0–4.5°C, best estimate 3°C | https://www.ipcc.ch/report/ar4-wg1/
- **2007** | IPCC | *Climate Change 2007: Impacts, Adaptation and Vulnerability (AR4 WGII)* | Observed impacts on all continents and oceans; 20–30% species at risk at >1.5–2.5°C | Up to 30% species at high extinction risk with 2.5°C warming | https://www.ipcc.ch/report/ar4-wg2/
- **2007** | IPCC | *Climate Change 2007: Mitigation of Climate Change (AR4 WGIII)* | Mitigation potential assessed across sectors; bottom-up vs top-down cost estimates | Stabilisation at 445–535 ppm CO2-eq estimated cost < 0.12% of global GDP per year | https://www.ipcc.ch/report/ar4-wg3/
- **2007** | IPCC | *Climate Change 2007: Synthesis Report (AR4 SYR)* | Integrated synthesis; shared IPCC's 2007 Nobel Peace Prize with Al Gore | "Warming of the climate system is unequivocal" — first use of unequivocal language | https://www.ipcc.ch/report/ar4-syr/
- **2007** | IPCC | *Nobel Peace Prize (shared)* | IPCC and Al Gore jointly awarded Nobel Peace Prize "for their efforts to build up and disseminate greater knowledge about man-made climate change" | Prize awarded 10 December 2007 in Oslo | https://www.nobelprize.org/prizes/peace/2007/ipcc/facts/
- **2007** | Wahl, E.R. & Ammann, C.M. | *Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence* | Systematically rebutted McIntyre-McKitrick criticisms; showed MBH hockey stick robust to methodological variants; principal-component critique did not substantively alter conclusions. | https://doi.org/10.1007/s10584-006-9105-7
- **2008** | Lenton, T.M., Held, H., Kriegler, E., Hall, J.W., Lucht, W., Rahmstorf, S. & Schellnhuber, H.J. | *Tipping elements in the Earth's climate system* | Defined "tipping elements" — large-scale climate subsystems with critical thresholds; catalogued AMOC, Greenland/Antarctic ice sheets, Amazon, Arctic sea ice, and others as policy-relevant risks. | https://doi.org/10.1073/pnas.0705414105
- **2008** | Mann, M.E., Zhang, Z., Hughes, M.K., Bradley, R.S., Miller, S.K., Rutherford, S. & Ni, F. | *Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia* | Expanded reconstruction with larger proxy network confirmed hockey stick shape; showed Medieval Warm Period regional, not global, and current warming unprecedented in 1300 years. | https://doi.org/10.1073/pnas.0805721105
- **2009** | Rockström, J., Steffen, W., Noone, K., Persson, Å., Chapin, F.S. III et al. | *A safe operating space for humanity* | Introduced planetary boundaries framework defining nine Earth-system thresholds; found three (climate change, biodiversity loss, nitrogen cycle) already transgressed as of 2009. | https://doi.org/10.1038/461472a
- **2010** | IPCC | *InterAcademy Council Review of IPCC Processes and Procedures* | IAC review commissioned after AR4 controversies; 22 recommendations on IPCC governance, communication, and review processes | Recommended conflict-of-interest policy, term limits for IPCC chair, improved handling of grey literature and uncertainty | https://www.ipcc.ch/site/assets/uploads/2019/02/IAC_report.pdf
- **2013** | IPCC | *Climate Change 2013: The Physical Science Basis (AR5 WGI)* | Human influence "extremely likely" (>95%) dominant cause of warming since 1950; comprehensive carbon budget framework introduced | +0.85°C warming 1880–2012; climate sensitivity 1.5–4.5°C (likely), best estimate ~3°C | https://www.ipcc.ch/report/ar5-wg1/
- **2014** | IPCC | *Climate Change 2014: Impacts, Adaptation, and Vulnerability (AR5 WGII)* | Impacts observed on all continents; risks for unique and threatened systems now detectable | "Risk of severe, pervasive, and irreversible impacts for people and ecosystems" at high warming | https://www.ipcc.ch/report/ar5-wg2/
- **2014** | IPCC | *Climate Change 2014: Mitigation of Climate Change (AR5 WGIII)* | Decarbonisation of energy by 2050 required for 2°C; renewable energy costs falling rapidly | Global GHG emissions grew 2.2% per year 2000–2010, up from 1.3% in 1970–2000 | https://www.ipcc.ch/report/ar5-wg3/
- **2014** | IPCC | *Climate Change 2014: Synthesis Report (AR5 SYR)* | Integrated synthesis; "Limiting climate change will require substantial and sustained reductions" | Limiting to 2°C requires 40–70% GHG reduction by 2050 vs 2010 | https://www.ipcc.ch/report/ar5-syr/
- **2018** | IPCC | *Global Warming of 1.5°C (SR1.5)* | Landmark assessment of 1.5°C vs 2°C; net-zero CO2 by ~2050 required to limit warming to 1.5°C | CO2 must reach net zero around 2050 (interquartile range 2045–2055); remaining carbon budget ~420 GtCO2 from 2018 for 1.5°C (66% probability) | https://www.ipcc.ch/sr15/
- **2019** | IPCC | *Climate Change and Land (SRCCL)* | Land is both a source and sink of GHGs; sustainable land management crucial; food systems contribute 21–37% of global GHG emissions | Desertification, land degradation, and food insecurity already exacerbated by climate change (high confidence) | https://www.ipcc.ch/srccl/
- **2019** | IPCC | *The Ocean and Cryosphere in a Changing Climate (SROCC)* | Ocean warming, acidification, and sea-level rise accelerating; cryosphere shrinking rapidly; major consequences for ecosystems and communities | Global mean sea level rose 15 cm over 20th century; rate has doubled since 1993 to ~3.6 mm/yr | https://www.ipcc.ch/srocc/
- **2019** | IPCC | *2019 Refinement to the 2006 IPCC Guidelines for National GHG Inventories* | Updated methodologies for compiling national GHG inventories; new categories including wetlands | Covers post-2006 scientific advances including land-use and forestry emissions | https://www.ipcc.ch/report/2019-refinement-to-the-2006-ipcc-guidelines-for-national-greenhouse-gas-inventories/
- **2021** | IPCC | *Climate Change 2021: The Physical Science Basis (AR6 WGI)* | "It is unequivocal that human influence has warmed the atmosphere, ocean and land"; 1.09°C warming 2011–2020 vs 1850–1900 | Observed warming 2011–2020 vs 1850–1900: 1.09 [0.95–1.20]°C; human-caused warming 1850–1900 to 2010–2019: 1.07°C best estimate [0.8–1.3°C]; climate sensitivity best estimate 3°C, likely range 2.5–4.0°C; remaining carbon budget for 1.5°C: ~400 GtCO2 from Jan 2020 (50% probability) | https://www.ipcc.ch/report/sixth-assessment-report-working-group-i/
- **2022** | IPCC | *Climate Change 2022: Impacts, Adaptation and Vulnerability (AR6 WGII)* | "Any further delay in concerted anticipatory global action on adaptation and mitigation will miss a brief and rapidly closing window of opportunity to secure a liveable and sustainable future for all" | 3.3–3.6 billion people live in contexts "highly vulnerable" to climate change; half of global population faces severe water scarcity for at least part of the year | https://www.ipcc.ch/report/sixth-assessment-report-working-group-ii/
- **2022** | IPCC | *Climate Change 2022: Mitigation of Climate Change (AR6 WGIII)* | Global GHG emissions must peak before 2025 to limit warming to 1.5°C; current policies put world on track for 3.2°C | Global net GHG emissions in 2019: 59 ± 6.6 GtCO2-eq — highest in human history; 45% cut needed by 2030 for 1.5°C | https://www.ipcc.ch/report/sixth-assessment-report-working-group-3/
- **2023** | IPCC | *Climate Change 2023: Synthesis Report (AR6 SYR)* | Integrated synthesis of all AR6 volumes; "The pace and scale of what has been done so far, and current plans, are insufficient to tackle climate change" | Current pledges put warming at 2.4–3.5°C; 1.5°C requires 43% GHG cut by 2030 from 2019 baseline | https://www.ipcc.ch/report/sixth-assessment-report-cycle/

### Attribution era, 2010–

*Tipping-point science, event attribution as an operational discipline, and the AR6 cycle.* (21 entries)

- **2011** | Min, S.-K., Zhang, X., Zwiers, F.W. & Hegerl, G.C. | *Human contribution to more-intense precipitation extremes* | Detected human fingerprint in observed increases in Northern Hemisphere extreme precipitation; anthropogenic forcing intensified heavy rainfall beyond natural variability. | https://doi.org/10.1038/nature09763
- **2011** | Pall, P., Aina, T., Stone, D.A., Stott, P.A., Nozawa, T., Hilberts, A., Lohmann, D. & Allen, M.R. | *Anthropogenic greenhouse gas contribution to flood risk in England and Wales in autumn 2000* | Large-ensemble attribution study found anthropogenic greenhouse gases increased risk of UK autumn 2000 floods by roughly a factor of two or more; first attribution of flood risk. | https://doi.org/10.1038/nature09762
- **2011** | Rahmstorf, S. & Coumou, D. | *Increase of extreme events in a warming world* | Theoretical framework showing heat-record frequency rises proportionally with warming trend; estimated ~80% probability 2010 Moscow July record would not occur without climate warming. | https://doi.org/10.1073/pnas.1101766108
- **2012** | Otto, F.E.L., Massey, N., van Oldenborgh, G.J., Jones, R. & Allen, M.R. | *Reconciling two approaches to attribution of the 2010 Russian heat wave* | Showed the same event can be internally generated in magnitude yet externally driven in occurrence probability; clarified how attribution framing determines conclusions. | https://doi.org/10.1029/2011gl050422
- **2012 (annual series)** | Peterson, T.C., Stott, P.A. & Herring, S. (eds, series continued by BAMS editorial team) | *Explaining Extreme Events of [Year] from a Climate Perspective* | Annual peer-reviewed compendium of event attribution studies begun in 2012; has evaluated hundreds of events and constitutes the primary literature archive of operational attribution. | https://www.ametsoc.org/index.cfm/ams/publications/bulletin-of-the-american-meteorological-society-bams/explaining-extreme-events/
- **2014–2015** | van Oldenborgh, G.J., Otto, F.E.L., Philip, S. & Kew, S. (World Weather Attribution founding team) | *World Weather Attribution initiative established* | Operational rapid attribution service co-founded by van Oldenborgh (KNMI), Otto (Oxford), Philip, and Kew; combines model ensembles, observations, and peer review for real-time event attribution. | https://www.worldweatherattribution.org
- **2015** | Fischer, E.M. & Knutti, R. | *Anthropogenic contribution to global occurrence of heavy-precipitation and high-temperature extremes* | Found anthropogenic forcing increased global frequency of heavy precipitation and heat extremes; ~75% of moderate heat extremes attributable to warming at current levels. | https://doi.org/10.1038/nclimate2617
- **2015** | Karl, T.R., Arguez, A., Huang, B., Lawrimore, J.H., McMahon, J., Menne, M.J., Peterson, T.C., Vose, R.S. & Zhang, H.-M. | *Possible artifacts of data biases in the recent global surface warming hiatus* | Updated NOAA temperature record with corrected SST and land data; early-21st-century warming at least as fast as late 20th century — apparent hiatus was data artefact. | https://doi.org/10.1126/science.aaa5632
- **2016** | Abatzoglou, J.T. & Williams, A.P. | *Impact of anthropogenic climate change on wildfire across western US forests* | Anthropogenic warming accounted for ~55% of increased fuel aridity 1979–2015; contributed an extra 4.2 million ha of forest fire area — doubled burned area attributable to climate change. | https://doi.org/10.1073/pnas.1607171113
- **2016** | DeConto, R.M. & Pollard, D. | *Contribution of Antarctica to past and future sea-level rise* | Including hydrofracturing and marine ice-cliff instability, Antarctica could contribute >1 m of sea-level rise by 2100 and >15 m by 2500 under high emissions. | https://doi.org/10.1038/nature17145
- **2016** | National Academies of Sciences, Engineering, and Medicine | *Attribution of Extreme Weather Events in the Context of Climate Change* | Comprehensive assessment of attribution science: heat attributable with high confidence; precipitation moderate; tornadoes and hail currently too uncertain; recommended rapid operational attribution. | https://doi.org/10.17226/21852
- **2017** | Diffenbaugh, N.S., Singh, D., Mankin, J.S., Horton, D.E., Swain, D.L., Touma, D. et al. | *Quantifying the influence of global warming on unprecedented extreme climate events* | Historical warming increased probability of record-hot months and days at >80% of observed area; framework for operational single-event attribution using large ensembles. | https://doi.org/10.1073/pnas.1618082114
- **2017** | Medhaug, I., Stolpe, M.B., Fischer, E.M. & Knutti, R. | *Reconciling controversies about the 'global warming hiatus'* | Showed apparent 1998–2012 hiatus arises from definition choice, dataset differences, and natural variability; combined factors reconcile models and observations, confirming continued human-driven warming. | https://doi.org/10.1038/nature22315
- **2017** | Supran, G. & Oreskes, N. | *Assessing ExxonMobil's climate change communications (1977–2014)* | Content analysis of 187 documents: 83% of peer-reviewed papers acknowledged human-caused climate change; only 12% of advertorials did — systematic public doubt campaign documented. | https://doi.org/10.1088/1748-9326/aa815f
- **2018** | Caesar, L., Rahmstorf, S., Robinson, A., Feulner, G. & Saba, V. | *Observed fingerprint of a weakening Atlantic Ocean overturning circulation* | SST fingerprint analysis showed AMOC has weakened ~15% (~3 Sv) since mid-20th century; corroborated by RAPID direct measurements showing record-low recent values. | https://doi.org/10.1038/s41586-018-0006-5
- **2019** | Williams, A.P., Abatzoglou, J.T., Gershunov, A., Guzman-Morales, J., Bishop, D.A., Balch, J.K. & Lettenmaier, D.P. | *Observed impacts of anthropogenic climate change on wildfire in California* | Climate change increased California burned area by ~500% since 1970s; two-thirds of increase attributable to vapour pressure deficit increases driven by anthropogenic warming. | https://doi.org/10.1029/2019EF001210
- **2022** | Armstrong McKay, D.I., Staal, A., Abrams, J.F., Winkelmann, R., Sakschewski, B., Loriani, S. et al. | *Exceeding 1.5°C global warming could trigger multiple climate tipping points* | Comprehensive reassessment identified 16 tipping elements; current ~1.1°C already within uncertainty range of five; six likely triggered between 1.5–2°C warming. | https://doi.org/10.1126/science.abn7950
- **2023** | Ditlevsen, P. & Ditlevsen, S. | *Warning of a forthcoming collapse of the Atlantic meridional overturning circulation* | Statistical analysis of AMOC early-warning signals (critical slowing down, increased variance) yields 95% confidence interval for tipping around 2037–2109 under current emissions. | https://doi.org/10.1038/s41467-023-39810-w
- **2023** | Hansen, J., Sato, M., Simons, L., von Schuckmann, K., Loeb, N., Osman, M. et al. | *Global warming in the pipeline* | Revised climate sensitivity to ~4.8°C per CO₂ doubling; equilibrium warming today is ~10°C without aerosols; projects >1.5°C in 2020s and >2°C before 2050. | https://doi.org/10.1093/oxfclm/kgad008
- **2023** | Richardson, K., Steffen, W., Lucht, W., Bendtsen, J., Cornell, S.E., Donges, J.F. et al. | *Earth beyond six of nine planetary boundaries* | Updated planetary boundaries framework finds six of nine now transgressed — climate, biosphere integrity, land use, biogeochemical flows, freshwater, novel entities — all worsening since 2015. | https://doi.org/10.1126/sciadv.adh2458
- **2023** | Supran, G., Rahmstorf, S. & Oreskes, N. | *Assessing ExxonMobil's global warming projections* | 63–83% of ExxonMobil's 1977–2003 internal climate projections accurately predicted subsequent warming; internal science was skillful and consistent with independent models, contrary to public messaging. | https://doi.org/10.1126/science.abk0063

### Official monitoring products and datasets

*The instruments and annual bulletins that constitute the authoritative measurement of the climate system.* (23 entries)

- **1988** (Continuous database (since 1988)) | CRED / UCLouvain | *EM-DAT (Emergency Events Database)* | Global database of natural and technological disasters from 1900-present; key reference for climate-related disaster statistics | https://www.emdat.be/
- **1993** (Annual (since 1993; formally called State of Global Climate from 2020)) | WMO | *State of the Global Climate (annual report)* | Comprehensive global-scale climate indicators: temperature, ocean heat content, sea-level rise, sea ice, glacier retreat, extreme events; 2024 report confirmed 1.55 ± 0.13°C above 1850–1900 — likely first calendar year above 1.5°C | https://wmo.int/publication-series/state-of-global-climate
- **1999** (Annual (since 1999; Bulletin No. 21 = 2025, covering 2024 data)) | WMO | *Greenhouse Gas Bulletin (GHG Bulletin)* | Globally averaged surface concentrations of CO2, CH4, N2O and other GHGs from WMO Global Atmosphere Watch network; 2024 values: CO2 423.9±0.2 ppm, CH4 1942±2 ppb, N2O 338.0±0.1 ppb | https://public.wmo.int/resources/publication-series/greenhouse-gas-bulletin
- **2000** | US Global Change Research Program (USGCRP) | *National Climate Assessment 1 (NCA1)* | First congressionally mandated US NCA; documented observed and projected climate impacts across US regions and sectors | https://www.globalchange.gov/content/national-climate-assessment
- **2007** (Annual (since 2007; key annual milestone)) | IEA | *World Energy Outlook (WEO)* | Comprehensive global energy projections including Net Zero by 2050 scenario (NZE); tracks energy sector emissions and clean energy investment trends | https://www.iea.org/reports/world-energy-outlook-2024
- **2009** (Annual (first published 2009, annual thereafter)) | Global Carbon Project (GCP) | *Global Carbon Budget (annual)* | Annual CO2 emissions from fossil fuels and land use, atmospheric growth, and ocean and land sinks; moved to dedicated site globalcarbonbudget.org; 2024 edition published November 2024 | https://globalcarbonbudget.org/
- **2009** | USGCRP | *National Climate Assessment 2 (NCA2 / "Global Climate Change Impacts in the United States")* | Updated US climate impacts assessment; first NCA to cover all major US sectors | https://www.globalchange.gov/browse/reports/global-climate-change-impacts-united-states
- **2010** (Annual (since 2010; 2024 edition is 15th)) | UNEP | *Emissions Gap Report (EGR)* | Tracks gap between current NDC pledges and emission levels consistent with 1.5°C and 2°C; 2024 edition: global GHG emissions hit record 57.1 GtCO2e in 2023; current policies lead to 2.6–3.1°C by 2100; 42% cut needed by 2030 for 1.5°C | https://www.unep.org/resources/emissions-gap-report-2024
- **Annual (since 2010)** | WMO | *WMO Global Annual to Decadal Climate Update* | Near-term (1–5 year) probabilistic temperature and precipitation forecasts using multi-model ensembles | https://wmo.int/publication-series/global-annual-decadal-climate-update
- **Annual (since 2014)** | UNEP | *Adaptation Gap Report* | Assesses progress on adaptation planning, finance, and implementation relative to growing climate risks | https://www.unep.org/adaptation-gap-report
- **2014** | USGCRP | *National Climate Assessment 3 (NCA3)* | Third US NCA; expanded coverage of human health and urban impacts; "Climate change, once considered an issue for a distant future, has moved firmly into the present" | https://nca2014.globalchange.gov/
- **Annual (since 2015)** | Lancet / academic consortium | *Lancet Countdown on Health and Climate Change* | Tracks 47 indicators linking climate change to human health; covers exposures, health vulnerabilities, health system resilience, finance, and policy | https://www.lancetcountdown.org/
- **2018** | USGCRP | *National Climate Assessment 4 (NCA4) — Volume I: Science (2017) and Volume II: Impacts, Risks, and Adaptation (2018)* | Without significant mitigation, annual average US temperatures could increase 9°F by late century; projected economic damages in billions | https://nca2018.globalchange.gov/
- **2023** (Annual (first 2023, covering 2022 data)) | Forster et al. / multi-institutional | *Indicators of Global Climate Change (IGCC)* | Annual peer-reviewed update of key climate system indicators including emissions, concentrations, radiative forcing, EEI, and attributed warming; provides timely IPCC-consistent data between assessment cycles; 2024 edition published June 2025 in Earth System Science Data | https://essd.copernicus.org/articles/17/2641/2025/
- **2023** | USGCRP | *National Climate Assessment 5 (NCA5) — "Fifth National Climate Assessment"* | Most comprehensive US climate assessment to date; "The effects of human-caused climate change are already far-reaching and worsening across every region of the United States"; US emissions peaked in 2007 but further cuts needed | https://nca2023.globalchange.gov/
- **2024** | European Environment Agency (EEA) | *European Climate Risk Assessment (EUCRA 2024)* | First comprehensive EU-wide climate risk assessment; identified 36 major climate risks for Europe across 5 clusters; many already at critical or catastrophic risk levels | https://www.eea.europa.eu/publications/european-climate-risk-assessment
- **Ongoing** (Updated monthly/annually) | Berkeley Earth | *Berkeley Earth Surface Temperature (BEST)* | Independent global surface temperature analysis using statistical methods to maximize station coverage; 2024: 1.54°C above 1850–1900 (consistent with other datasets) | https://berkeleyearth.org/global-temperature-report/
- **Ongoing** (Annual summary (ERA5 data updated in near real-time)) | Copernicus Climate Change Service (C3S) / ECMWF | *ERA5 and C3S Global Climate Highlights (Annual)* | ERA5 reanalysis-based global temperature and climate indicator summaries; 2024 Global Climate Highlights confirmed 2024 at 1.60°C above 1850–1900 using ERA5 (the highest of the dataset range), making it "the first calendar year to exceed 1.5°C above that level" | https://climate.copernicus.eu/global-climate-highlights-2024
- **Ongoing** (Monthly, updated near-real-time) | NASA GISS | *GISTEMP v4 (GISS Surface Temperature Analysis)* | Global land-ocean temperature index from 1880-present based on GHCN-v4 + ERSST v5; 2024 annual mean: +1.28°C relative to 1951–1980 baseline (warmest year on record); 2025: +1.19°C (2nd or 3rd warmest) | https://data.giss.nasa.gov/gistemp/
- **Ongoing** (Monthly and annual) | NOAA/NCEI | *Global Climate Reports (monthly and annual)* | Global surface temperature rankings, precipitation, and extreme event statistics; 2024 ranked warmest year in NOAA record (1.46°C above 1850–1900) | https://www.ncei.noaa.gov/access/monitoring/monthly-report/global
- **Ongoing** (Annual (as part of above)) | NOAA/NCEI | *NOAA Annual Greenhouse Gas Index (AGGI)* | Measures radiative forcing of long-lived GHGs relative to 1990 baseline; from 1990 to 2024, radiative forcing increased 54%, with CO2 accounting for ~81% of the increase | https://www.esrl.noaa.gov/gmd/aggi/
- **Ongoing** (Updated approximately annually) | UK Met Office / Hadley Centre + University of East Anglia CRU | *HadCRUT5* | Global surface temperature dataset from 1850-present combining land (CRUTEM5) and marine (HadSST4) observations; 2024: 1.51–1.55°C above 1850–1900 (methodologically consistent with WMO consolidated assessment) | https://www.metoffice.gov.uk/hadobs/hadcrut5/
- **Ongoing** (Annual/irregular) | WMO and UNDRR | *WMO Atlas of Mortality and Economic Losses from Weather, Climate, and Water Extremes* | Decadal statistics on weather-related disasters; 1970–2019 edition: over 11,000 disasters attributed to weather/climate/water causing $3.64 trillion in economic losses | https://library.wmo.int/idurl/4/57564

### The Australian record

*One of the longest continuous atmospheric records on Earth, and a canonical laboratory for compound disaster.* (14 entries)

- **1972–ongoing** | CSIRO Division of Atmospheric Physics (later Atmospheric Research, now Oceans and Atmosphere) | *CSIRO Atmospheric CO2 Monitoring Programme — Pearman, Garratt and Fraser* | Aircraft-based CO2 programme begun 21 March 1972 by J.R. Garratt and G.I. Pearman, with P.J. Fraser joining 1974. First samples collected at 4.0 km over Bass Strait recorded 327 ppm. Programme expanded to non-CO2 greenhouse gases (CFCs etc.) from ~1975. Led directly to establishment of Cape Grim station. Fraser et al. identified… | 327 ppm (first sample, March 1972) | https://research.csiro.au/acc/fifty-years-of-carbon-dioxide-co2-measurements-in-the-background-atmosphere-of-se-australia/
- **1976/ongoing** | Bureau of Meteorology + CSIRO | *Kennaook / Cape Grim Baseline Air Pollution Station* | Established 1976 on Tasmania's north-west tip. One of only three international reference stations measuring clean Southern Hemisphere baseline air unaffected by local pollution. Part of the WMO Global Atmosphere Watch Programme. Co-managed by BoM (operates the station) and CSIRO (Cape Grim Science Program). Measures CO2, CH4, N2O, >80… | 330 ppm (1976) → ~413 ppm (2022) | https://www.bom.gov.au/resources/observation-network/kennaook/cape-grim-baseline-air-pollution-station
- **1980s/ongoing** | AIMS | *AIMS Long-Term Monitoring Programme (LTMP) — Great Barrier Reef* | AIMS has monitored GBR coral reefs since the early 1980s (WA reefs since early 1990s). 94 reefs surveyed per annual cycle (2023/24). Mass bleaching events on GBR documented with full-scale surveys: 1998, 2002, 2016, 2017, 2020, 2022, 2024, 2025. The 2023/24 report found hard coral cover increased to regional highs (Northern GBR:… | 5th bleaching (2024): largest spatial footprint recorded | https://www.aims.gov.au/monitoring-great-barrier-reef/gbr-condition-summary-2023-24
- **1996** | CSIRO / Australian Antarctic Division | *Law Dome Ice Core CO2 Record (Etheridge et al. 1996)* | High-resolution CO2 record covering 1006 AD to 1978 AD from three ice cores at Law Dome, Antarctica (a site with unusually high snow accumulation giving unparalleled age resolution). Record overlaps with direct atmospheric measurements by up to 20 years. Preindustrial CO2: 275–284 ppm (lower 1550–1800 AD). Uncertainty: ±1.2 ppm (1σ).… | Preindustrial CO2: 275–284 ppm | https://agupubs.onlinelibrary.wiley.com/doi/10.1029/95JD03410
- **2008** (2008 Final Report; 2011 Update) | Professor Ross Garnaut / Commonwealth of Australia | *Garnaut Climate Change Review (2008) and Update (2011)* | Independent review commissioned by all Australian governments. 2008 Final Report included fire danger analysis by Bureau of Meteorology/CSIRO scientists led by Dr Chris Lucas, projecting: fire seasons will start earlier, end slightly later, and be generally more intense; this should be directly observable by 2020. Predicted very high… | +10–30% very high fire danger days by 2020 (high warming scenario) | https://www.canberratimes.com.au/story/6567568/ross-garnauts-fire-prediction-a-decade-on/
- **2010, 2015** | Australian Academy of Science | *The Science of Climate Change: Questions and Answers (2010 and 2015 editions)* | Authoritative public-facing Q&A on climate science prepared by a working group led by Dr Ian Allison and Prof Mike Raupach (co-chairs), reviewed by oversight committee chaired by Prof John Zillman. The 2015 edition updated the 2010 booklet. Covers: attribution of observed warming to human activities; observed Australian changes… | https://science.org.au/our-work/resources-reports/reports-publications/science-climate-change-questions-answers
- **Biennial 2010–2024** | CSIRO + Bureau of Meteorology | *State of the Climate (biennial report series)* | Biennial synthesis of national and international climate research including observations, analyses and projections. First edition 2010; eighth edition 2024. Headline findings from SOTC 2024: Australia has warmed 1.51 ± 0.23°C since 1910; SSTs +1.08°C since 1900; SW Australia April–October rainfall −16% since 1970, May–July −20% since… | Warming: +1.51 ± 0.23°C since 1910 | https://www.csiro.au/-/media/Environment/SOTC-2024/24-00239_REPORT_StateoftheClimate2024_241022.pdf
- **2011** (2011/ongoing (v2.6 Nov 2025)) | Bureau of Meteorology | *ACORN-SAT (Australian Climate Observations Reference Network – Surface Air Temperature)* | Homogenised temperature dataset using 112 weather stations across Australia for long-term trend analysis. First published 2011; major update to version 2 in 2018; current version 2.6 released November 2025. Uses homogenisation to remove artificial influences (site relocations, equipment upgrades). Methods independently peer-reviewed… | 112 stations; version 2.6 (Nov 2025) | https://reg.bom.gov.au/climate/data/acorn-sat/
- **2014** (2014, and subsequent reviews) | Climate Change Authority | *Targets and Progress Reviews* | Statutory reviews of Australia's greenhouse gas reduction targets and progress. First major review: 2014. Subsequent reviews include 2017 and 2022 Emissions Reduction Progress reports. The 2014 review assessed Australia's medium and long-term targets against a global 2°C budget. | https://www.climatechangeauthority.gov.au/publications/2014-targets-and-progress-review
- **2015/CMIP6 updated** | CSIRO / BoM / Australian Climate Service | *National Climate Projections (Climate Change in Australia)* | Initial national projections released 2015 under CMIP5. NESP NextGen Projections workshop 2017; report 2021; CMIP6-based projections now being finalised under NPCP. Provide application-ready, locally relevant datasets under two SSP scenarios (SSP1-2.6, SSP3-7.0) and others; bracket Paris-aligned vs high-emissions futures. | https://climatechangeinaustralia.gov.au/en/overview/about-site/landscape/
- **2020–ongoing** | Australian Climate Service (ACS) | *Australian Climate Service* | Created following the Royal Commission's recommendations, the ACS is a partnership of BoM, CSIRO, Geoscience Australia and the Australian Bureau of Statistics to provide climate science and data for emergency management, adaptation and risk. Operates Program 3 of CMIP6-based national climate projections in partnership with state… | https://climatechangeinaustralia.gov.au/en/overview/about-site/landscape/
- **2020** | Royal Commission into National Natural Disaster Arrangements | *Royal Commission into National Natural Disaster Arrangements (Final Report, October 2020)* | Established 20 February 2020 in response to the 2019-20 bushfire season. Commissioners: Air Chief Marshal Mark Binskin, Hon. Dr Annabelle Bennett, Prof. Andrew Macintosh. Report published 28 October 2020. Key findings: the 2019-20 fires were the worst in Australia's history; 33 people died directly; >3 billion animals killed or… | 33 direct deaths; >24M ha burned; >3 billion animals | https://oia.pmc.gov.au/sites/default/files/posts/2022/11/Royal%20Commission%20into%20National%20Natural%20Disaster%20Arrangements%20-%20Report%20%20%5Baccessible%5D.pdf
- **March 2021** | Australian Academy of Science | *The Risks to Australia of a 3°C Warmer World* | March 2021 report superseding the Q&A as the Academy's updated climate science communication. Synthesises observed impacts and risks from a 3°C warming trajectory across four domains: ecosystems, food production, cities and towns, health and wellbeing. Noted as the Academy's updated climate change information replacing Q&A. | https://science.org.au/our-focus/science-everyone/science-climate-change
- **2022** (2022 (most recent; next due Dec 2026)) | DCCEEW (independent authors) | *Australia State of the Environment Report (SoE 2021, released July 2022)* | Five-yearly independent assessment of 12 environmental themes. The 2021 SoE (released July 2022) found the general outlook for Australia's environment is deteriorating; climate change is affecting every aspect. First edition to include dedicated Extreme Events and Indigenous chapters. Next report due December 2026. Led by Prof. Emma… | https://soe.dcceew.gov.au/

## Event dossiers

56 dossiers. Attribution status: 25 robust, 16 partial or contextual, 12 with no formal study, 3 pending.

### Global, 2000–2025

#### European heatwave (Jun–Aug 2003)

- Region: Western Europe
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: ~70,000 excess deaths across 12 European countries (Robine et al. 2008, Comptes Rendus Biologies); France alone ~14,800–19,500. Economic losses ~€13bn (EC Joint Research Centre).
- Attribution: Human influence at least doubled the risk of a summer this hot; best estimate a fourfold increase.
- Citation: Stott, Stone & Allen 2004, Nature 432:610–614 — https://doi.org/10.1038/nature03089
- Note: The founding paper of probabilistic event attribution. Everything downstream in this section descends from it.

#### Hurricane Katrina (23–31 Aug 2005)

- Region: US Gulf Coast
- Hazard: Storm
- Attribution status: NONE — no formal attribution study exists
- Impact: 1,833 confirmed deaths (NOAA NHC, revised 2023). Storm surge to 8.5 m in Mississippi. $125bn damage in 2005 dollars — costliest US hurricane at the time.
- Attribution: No formal attribution study. In 2005 the method barely existed; rapid attribution was not routinely applied to cyclones until 2017. Emanuel (2005, Nature) had shown Atlantic hurricane intensity rising ~50% since the 1970s in step with sea surface temperature.
- Citation: Emanuel 2005, Nature 436:686–688 — https://www.nature.com/articles/nature03906
- Note: Included precisely because it cannot be attributed. Katrina marks the limit of what the science could say at the time.

#### Russian heatwave (Jun–Aug 2010)

- Region: Western Russia
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: ~55,000 excess deaths (modelled; Barriopedro et al. 2011, Science); Rosstat registered ~56,000 for July–August. ~500,000 ha of peat and forest fires. ~$15bn damages (World Bank).
- Attribution: Initially contested: Dole et al. (2011) called it "mainly natural in origin"; Rahmstorf & Coumou (2011) found an 80% probability the Moscow July record would not have occurred without warming. Otto et al. reconciled them — the same event can be internally generated in magnitude yet externally driven in probability.
- Citation: Otto et al. 2012, GRL 39:L04702 — https://doi.org/10.1029/2011GL050422
- Note: The methodological turning point: it showed that how you frame the question determines the answer, and both answers can be right.

#### Pakistan floods (Jul–Sep 2010)

- Region: Pakistan
- Hazard: Flood
- Attribution status: NONE — no formal attribution study exists
- Impact: 1,985 deaths (NDMA); ~20 million people affected — the most cited figure for any single flood in recorded history. ~160,000 km² inundated (a fifth of the country). ~$9.7bn damages (World Bank/ADB).
- Attribution: No formal attribution study. Trenberth & Fasullo (2012) discussed the thermodynamic drivers, but no probability-ratio study was published.
- Note: A defining 21st-century disaster with no attribution study — a gap that reflects where attribution effort has historically been spent.

#### Thailand floods (Jul–Dec 2011)

- Region: Thailand
- Hazard: Flood
- Attribution status: NONE — no formal attribution study exists
- Impact: 815 deaths (Thai DDPM); ~13 million affected; ~$45bn losses (World Bank) — 4th costliest disaster in history at the time. Global hard-disk-drive production fell ~40% as Chao Phraya basin plants flooded.
- Attribution: No formal attribution study.
- Note: The first climate-linked disaster to visibly rupture global supply chains.

#### Hurricane Sandy (22–31 Oct 2012)

- Region: US Northeast, Caribbean
- Hazard: Storm
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: 233 deaths total (147 in the US). Storm surge ~4.3 m in New York Harbor — highest since records began in 1821. $65bn damage; ~650,000 homes damaged or destroyed.
- Attribution: No single-event probability study. Lackmann (2015, BAMS) estimated warming increased Sandy's precipitation by 6–15%; sea-level rise measurably enlarged the surge footprint.
- Citation: Lackmann 2015, BAMS 96:1763–1778 — https://journals.ametsoc.org/view/journals/bams/96/10/bams-d-14-00101.1.xml

#### Typhoon Haiyan (Yolanda) (2–11 Nov 2013)

- Region: Philippines
- Hazard: Storm
- Attribution status: NONE — no formal attribution study exists
- Impact: 6,340 confirmed deaths, 1,062 missing (NDRRMC final report); ~4 million displaced; ~1.1 million homes damaged. Gusts to 315 km/h; 5–7 m storm surge at Tacloban. ~$12.9bn losses.
- Attribution: No formal single-event probability study. Assessed contextually in BAMS Explaining Extreme Events of 2013; Takayabu et al. (2015) examined intensification.
- Citation: BAMS Explaining Extreme Events of 2013 — https://www.ametsoc.org/index.cfm/ams/publications/bulletin-of-the-american-meteorological-society-bams/explaining-extreme-events/

#### India & Pakistan heatwaves (May–Jun 2015)

- Region: South Asia
- Hazard: Heat
- Attribution status: NONE — no formal attribution study exists
- Impact: India ~2,500 official deaths (NDMA; Andhra Pradesh 1,636, Telangana ~1,084), widely regarded as an undercount. Karachi ~1,200–1,300 deaths. Temperatures to 48°C.
- Attribution: No formal single-event attribution study with a quantitative probability ratio was published.
- Note: Two of the deadliest heat events of the decade, and neither received the treatment given to European heat two years later.

#### Third global coral bleaching event (2014–2017 (peak 2016))

- Region: Global oceans
- Hazard: Marine
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Bleaching-level heat stress across 68.2% of the world's coral reef area (NOAA Coral Reef Watch). ~91% of surveyed Great Barrier Reef reefs bleached in 2016; roughly half the GBR's coral died across 2016–17.
- Attribution: Without global warming the probability of bleaching as severe as 2016 would have been close to zero. Warming moved bleaching-level thermal stress from rare to routine.
- Citation: Hughes et al. 2017, Nature 543:373–377 — https://doi.org/10.1038/nature21707

#### California drought (2011–2017)

- Region: California, USA
- Hazard: Drought
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: 2014 assessed as the most severe statewide drought in at least 1,200 years. ~$2.7bn agricultural losses in 2014 alone (UC Davis); severe groundwater depletion; primed the fire seasons that followed.
- Attribution: Anthropogenic warming made the probability of a drought this severe roughly 3× higher than in a natural climate.
- Citation: Diffenbaugh et al. 2015, PNAS 112:3931–3936 — https://doi.org/10.1073/pnas.1422385112

#### Hurricane Harvey (25–31 Aug 2017)

- Region: Houston, Texas
- Hazard: Flood
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: 68 direct deaths (NOAA NHC); ~$125bn damage. Over 60 inches (1,524 mm) of rain — the highest accumulation from any US tropical cyclone. ~300,000 structures damaged.
- Attribution: Rainfall of this magnitude made ~3× more likely, with intensity increased 15–38%. Emanuel put the 3-day return period at ~1-in-9,000 years in a 1981 climate versus ~1-in-2,500 by 2017.
- Citation: Emanuel 2017, PNAS; van Oldenborgh et al. 2017, ERL 12:124009 — https://doi.org/10.1088/1748-9326/aa9ef2
- Note: The event that made hurricane rainfall attribution routine, even as track and intensity attribution remained hard.

#### Hurricane Maria (16–30 Sep 2017)

- Region: Puerto Rico
- Hazard: Storm
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: Official toll revised from 64 to 2,975 (GWU Milken Institute, 2018); Kishore et al. (NEJM) estimated 4,645. $90bn damage; the longest blackout in US history.
- Attribution: Climate change increased the probability of a hurricane this intense making landfall on Puerto Rico by ~4.85×; rainfall ~9.7% more intense.
- Citation: Wang et al. 2018, GRL 45:4085–4094 — https://doi.org/10.1029/2018GL077739
- Note: The 64-to-2,975 revision is a lesson in disaster accounting: most climate deaths are not counted at the time.

#### Camp Fire (Paradise) (8–25 Nov 2018)

- Region: Butte County, California
- Hazard: Fire
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: 85 deaths — the deadliest California wildfire on record. 18,804 structures destroyed; the town of Paradise almost entirely erased. 153,336 acres burned; ~$16.5bn total losses.
- Attribution: No single-event probability study. Ignition was a utility transmission fault, which complicates attribution; but the fire weather sits inside a strongly attributed trend — anthropogenic warming accounted for ~55% of the increase in fuel aridity across western US forests 1979–2015.
- Citation: Abatzoglou & Williams 2016, PNAS 113:11770–11775 — https://doi.org/10.1073/pnas.1607171113

#### Cyclone Idai (4–21 Mar 2019)

- Region: Mozambique, Zimbabwe, Malawi
- Hazard: Storm
- Attribution status: NONE — no formal attribution study exists
- Impact: 1,302+ deaths across three countries; ~3 million affected. Over 90% of the city of Beira damaged; ~90,000 homes destroyed. ~$2bn losses (OCHA).
- Attribution: No formal attribution study.

#### Pacific Northwest heat dome (25 Jun – 2 Jul 2021)

- Region: British Columbia, Oregon, Washington
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Lytton, BC hit 49.6°C — a Canadian all-time record — then burned to the ground the next day. ~619 excess heat deaths in BC (Coroners Service); several hundred more across Oregon and Washington. Portland reached 46.7°C.
- Attribution: Virtually impossible without human-caused climate change. At least 150× rarer in a pre-industrial climate; roughly 2°C hotter than it would otherwise have been; ~1-in-1,000-year event even today.
- Citation: WWA 2021; Philip et al. 2022, ASCMO 8:119–145 — https://www.worldweatherattribution.org/western-north-american-extreme-heat-virtually-impossible-without-human-caused-climate-change/
- Note: The event that broke the models: it exceeded what climate models said was possible at current warming.

#### German & Belgian floods (Ahr valley) (12–16 Jul 2021)

- Region: Germany, Belgium
- Hazard: Flood
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: 184 deaths in Germany, 38 in Belgium (~222–240 regionally). The Ahr flood was assessed as a 500-year event or rarer. Over €33bn damage in Germany alone.
- Attribution: Rainfall intensity increased 3–19%; likelihood increased by a factor of 1.2 to 9 versus a 1.2°C cooler climate. Local records were broken by such margins that regional analysis had to substitute for local trend detection.
- Citation: WWA / Kreienkamp et al. 2021 — https://www.worldweatherattribution.org/heavy-rainfall-which-led-to-severe-flooding-in-western-europe-made-more-likely-by-climate-change/

#### Siberian / Yakutia fires (Jun–Sep 2021)

- Region: Sakha Republic, Russia
- Hazard: Fire
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: ~18.8 million hectares burned across Russia — a record. Smoke reached the North Pole. ~970 megatonnes of CO₂ emitted (Copernicus Atmosphere Monitoring Service).
- Attribution: No single-event study for the 2021 fires. The 2020 Siberian heatwave that set up these conditions was found almost impossible without climate change — at least 600 times less likely in a pre-industrial climate.
- Citation: WWA 2020 (Siberian heat) — https://www.worldweatherattribution.org/siberian-heatwave-of-2020-almost-impossible-without-climate-change/

#### UK exceeds 40°C (18–19 Jul 2022)

- Region: England
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Coningsby, Lincolnshire recorded 40.3°C — the UK's first 40°C, beating the old record by 1.6°C. 46 stations exceeded the previous record. ~2,803 excess deaths in England and Wales that week (UKHSA provisional).
- Attribution: Made at least 10× more likely by climate change; the heat would have been ~4°C cooler in a pre-industrial climate on observational estimates (models suggest ~2°C, which the authors judged an underestimate).
- Citation: Zachariah et al., WWA 2022 — https://www.worldweatherattribution.org/without-human-caused-climate-change-temperatures-of-40c-in-the-uk-would-have-been-extremely-unlikely/

#### India & Pakistan pre-monsoon heat (Mar–May 2022)

- Region: South Asia
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: India's hottest March on record. Delhi 49.2°C; Jacobabad 49°C; Nawabshah 50°C. Official death counts in the dozens but analysts estimate hundreds to thousands, given systematic under-recording. Wheat harvests hit; India restricted exports.
- Attribution: Made ~30× more likely by human-induced climate change. In a 2°C world such events would recur roughly every five years.
- Citation: WWA 2022 — https://www.worldweatherattribution.org/climate-change-made-the-devastating-early-heat-in-india-and-pakistan-30-times-more-likely/

#### Pakistan floods (Jun–Aug 2022)

- Region: Pakistan
- Hazard: Flood
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: ~1,739 deaths (NDMA); 33 million people affected; 1.7 million homes destroyed; ~$30bn damage. Sindh and Balochistan received seven to eight times normal August rainfall; ~18,000 km² of cropland inundated.
- Attribution: 5-day extreme rainfall over Sindh and Balochistan now ~75% more intense, and 60-day Indus basin rainfall ~50% more intense, than in a 1.2°C cooler climate. Observed changes exceeded model estimates, suggesting the finding is conservative.
- Citation: WWA 2022; Otto et al. 2023, ERL — https://www.worldweatherattribution.org/climate-change-likely-increased-extreme-monsoon-rainfall-flooding-highly-vulnerable-communities-in-pakistan/
- Note: Pakistan contributes well under 1% of global emissions. The event became the reference case for loss-and-damage negotiations.

#### European drought (Spring–autumn 2022)

- Region: Europe
- Hazard: Drought
- Attribution status: NONE — no formal attribution study exists
- Impact: Assessed by the EU Joint Research Centre as potentially the worst drought in 500 years. Over a quarter of EU territory at drought "alert" level; 90 of 96 French departments under water restriction; Loire, Rhine, Danube and Po at historic lows; hydropower severely curtailed.
- Attribution: No formal probability-ratio study. The "500-year" figure is the JRC's assessment from its Combined Drought Indicator, not an attribution finding — a distinction routinely lost in reporting.
- Citation: JRC / Copernicus Emergency Management Service, Sep 2022 — https://joint-research-centre.ec.europa.eu/jrc-news-and-updates/drought-europe-august-2022-2022-08-22_en

#### Canadian wildfire season (May–Oct 2023)

- Region: Canada
- Hazard: Fire
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: ~18.4 million hectares burned — more than double the previous record of ~7.1 Mha (1995). ~215,000 people evacuated including all of Yellowknife. Smoke drove air quality indices above 500 in northeastern US cities.
- Attribution: Extreme fire weather made more than five times as likely by human-caused climate change; the record area burned also made much more likely.
- Citation: Kirchmeier-Young et al. 2024, npj Clim. Atmos. Sci. 7:316 — https://doi.org/10.1038/s41612-024-00841-9

#### Southern Europe, US Southwest & China heat (Jul 2023)

- Region: Three continents
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Phoenix endured 31 consecutive days above 43°C; Death Valley hit 53.3°C; Sanbao, Xinjiang set an all-China record ~52.2°C; Sardinia reached 47°C. Italy recorded an estimated ~900–2,000 heat deaths.
- Attribution: In southern Europe and the US/Mexico the observed heat was "virtually impossible" without climate change. Equivalent-likelihood events would have been ~2.5°C cooler in southern Europe, ~2°C in North America, ~1°C in China. At 2°C warming, such heat recurs every 2–5 years.
- Citation: Zachariah et al., WWA 2023 — https://www.worldweatherattribution.org/extreme-heat-in-north-america-europe-and-china-in-july-2023-made-much-more-likely-by-climate-change/

#### Maui / Lahaina fire (8–12 Aug 2023)

- Region: Hawaii, USA
- Hazard: Fire
- Attribution status: NONE — no formal attribution study exists
- Impact: 115 confirmed deaths — the deadliest US wildfire since 1918. ~2,207 structures destroyed; historic Lahaina largely burned. Only ~2,170 acres, but almost entirely urban. ~$13–14bn total losses.
- Attribution: No formal attribution study. A compound event — hurricane-driven downslope winds meeting drought-cured invasive grasses — that current methods handle poorly.

#### Storm Daniel & the Derna dam collapse (4–11 Sep 2023)

- Region: Libya, Greece, Türkiye, Bulgaria
- Hazard: Flood
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: Two dams above Derna failed, sending a torrent through the city. Death toll disputed: 4,333 (Libyan Red Crescent) to 11,300+ (UN OCHA reporting), with some Libyan officials citing far higher. No systematic count exists. Greece: 17 deaths; Bulgaria: 5.
- Attribution: Attribution exists for the rainfall — WWA reported the extreme Mediterranean rainfall made up to 50× more likely and 40–50% more intense. The catastrophe itself was an infrastructure and governance failure compounding the meteorology.
- Citation: WWA 2023 (see caveat — original report URL now unresolved) — https://www.worldweatherattribution.org/
- Note: The clearest case in this record that a climate signal becomes a body count only through the state of the built environment.

#### Amazon drought (2022–2024)

- Region: Amazon basin, Brazil
- Hazard: Drought
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: The worst Amazon drought on record. The Rio Negro at Manaus fell to ~13.59 m — its lowest since records began in 1902. ~500,000 people affected in Amazonas state; mass die-offs of river dolphins and fish.
- Attribution: Compound El Niño and anthropogenic warming; WWA assessed the climate change contribution but a firm probability ratio for this event was not confirmed.
- Citation: WWA 2024 — https://www.worldweatherattribution.org/

#### Horn of Africa drought (Oct 2020 – 2023)

- Region: Ethiopia, Somalia, Kenya
- Hazard: Drought
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Five consecutive failed rainy seasons — the region's worst drought in at least 40 years. ~4.35 million people needing assistance in Kenya alone; mass livestock deaths and a malnutrition emergency.
- Attribution: A carefully split result: climate change did not significantly reduce rainfall — that deficit was largely La Niña. But warming-driven evaporation substantially worsened agricultural drought, roughly doubling the likelihood of a drought this severe (26-year return period now, ~55 years in a 1.2°C cooler climate).
- Citation: WWA 2023 — https://www.worldweatherattribution.org/human-induced-climate-change-increased-drought-severity-in-southern-horn-of-africa/
- Note: An honest attribution result that refuses the simple headline — and is more useful for it.

#### Fourth global coral bleaching event (Jan 2023 – ~2025)

- Region: Global oceans
- Hazard: Marine
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: Declared by NOAA on 15 April 2024. Bleaching-level heat stress reached ~84.4% of the world's coral reef area across at least 83 countries — far surpassing the 68.2% of the previous record event. Assessed as ended by mid-2025.
- Attribution: No single-event probability study. IPCC AR6 attributes intensifying coral bleaching to human-caused warming with very high confidence.
- Citation: NOAA Coral Reef Watch; ICRI — https://coralreefwatch.noaa.gov/

#### Record-low Antarctic sea ice (Feb 2023 onward)

- Region: Southern Ocean
- Hazard: Ice
- Attribution status: NONE — no formal attribution study exists
- Impact: February 2023 minimum of ~1.79 million km² — the lowest in the satellite record, roughly 1 million km² below the previous low and 5–6 standard deviations below the 1981–2010 mean. Near-record lows followed in 2024 and 2025.
- Attribution: No probability-ratio study. The long-term driver is human-caused warming with high confidence, but the 2023 collapse exceeded what models predicted and remains only partly explained.
- Citation: NSIDC; Purich & Doddridge 2023 — https://nsidc.org/arcticseaicenews/
- Note: Where the record runs ahead of the science. The honest statement is that this surprised the field.

#### Hurricanes Helene & Milton (Sep–Oct 2024)

- Region: Southeastern USA
- Hazard: Storm
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Helene: at least 227 deaths, with catastrophic flash flooding in the Appalachians hundreds of kilometres inland. Milton: 16+ deaths, mostly from spawned tornadoes; intensified below 900 mbar over the Gulf.
- Attribution: Heavy one-day rainfall from these storms 20–30% more intense and about twice as likely today. Gulf sea surface temperatures that fuelled Milton were made 400–800× more likely by climate change; without warming Milton would likely have landed as a Category 2 rather than 3.
- Citation: WWA, 11 Oct 2024 — https://www.worldweatherattribution.org/climate-change-key-driver-of-catastrophic-impacts-of-hurricane-helene-that-devastated-both-coastal-and-inland-communities/

#### Valencia DANA floods (29–30 Oct 2024)

- Region: Valencia, Spain
- Hazard: Flood
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: More than 200 deaths (~232 by end-November per Spanish authorities) — Europe's deadliest flood since 1967. Chiva received over 400 mm in under 24 hours.
- Attribution: WWA published a super-rapid observations-only analysis, explicitly not a formal attribution study: heavy rainfall is intensifying in the region, consistent with climate change, but no probability ratio was issued.
- Citation: WWA, 4 Nov 2024 — https://www.worldweatherattribution.org/extreme-downpours-increasing-in-southeastern-spain-as-fossil-fuel-emissions-heat-the-climate/
- Note: A case where the responsible scientific answer was to publish less than the public wanted.

#### Los Angeles fires (Palisades & Eaton) (7–31 Jan 2025)

- Region: Los Angeles County, California
- Hazard: Fire
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: ~29 deaths; over 16,000 structures destroyed; insured losses ~$27bn with total economic loss estimates far higher. Driven by exceptional Santa Ana winds after an October–December with virtually no rain.
- Attribution: The fire-weather conditions are now expected roughly once every 17 years — about 35% more likely than in a 1.3°C cooler climate, with fire weather index intensity up ~6%. The preceding drought was 2.4× more likely, and the dry season has lengthened by ~23 days, widening the overlap with Santa Ana wind season.
- Citation: WWA, 28 Jan 2025 — https://www.worldweatherattribution.org/climate-change-increased-the-likelihood-of-wildfire-disaster-in-highly-exposed-los-angeles-area/
- Note: Note the modest 35% figure against the enormous loss. Exposure, not just hazard, produced this disaster.

#### Texas Hill Country flood (3–7 Jul 2025)

- Region: Kerr County, Texas
- Hazard: Flood
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: 119 deaths confirmed in Kerr County (Texas Rangers, 8 Aug 2025), ~136 across the broader event; 27 died at Camp Mystic. The Guadalupe River rose roughly 11 m in an hour before dawn on 4 July.
- Attribution: A ClimaMeter rapid analysis — not a full attribution study — found conditions up to 7% wetter than comparable past events, and that natural variability alone could not explain the increase. Authors flagged low confidence given how exceptional the event was.
- Citation: Faranda, Ginesta & Alberti 2025, ClimaMeter — https://www.climameter.org/20250704-texas-floods

#### Türkiye, Cyprus & Greece fires (Aug 2025)

- Region: Eastern Mediterranean
- Hazard: Fire
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Deadly fires across three countries during an extreme Mediterranean fire season.
- Attribution: The weather conditions behind the fires were made 10× more likely by climate change.
- Citation: WWA, 28 Aug 2025 — https://www.worldweatherattribution.org/weather-conditions-leading-to-deadly-wildfires-in-turkiye-cyprus-and-greece-made-10-times-more-likely-due-to-climate-change/

#### Fennoscandian heatwave (Aug 2025)

- Region: Norway, Sweden, Finland
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: An intense two-week heatwave across the Nordic countries. Mortality figures not established in available sources.
- Attribution: Made both hotter and more likely by climate change.
- Citation: WWA, 14 Aug 2025 — https://www.worldweatherattribution.org/intense-two-week-heatwave-in-fennoscandia-hotter-and-more-likely-due-to-climate-change/

### Australia

#### Millennium Drought (c. 1997–2010)

- Region: South-eastern Australia
- Hazard: Drought
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: Murray–Darling inflows fell to historic lows; major city storages approached critical levels. Ended only with the 2010–11 La Niña rains.
- Attribution: No single rapid attribution study, but the underlying cool-season rainfall decline is partly human-caused: south-west Australian April–October rainfall is down ~16% since 1970, south-east down ~9% since 1994, linked to a poleward shift of the subtropical ridge under greenhouse forcing.
- Citation: CSIRO–BoM State of the Climate 2024 — https://www.csiro.au/en/research/environmental-impacts/climate-change/state-of-the-climate

#### Black Saturday bushfires (7 Feb 2009)

- Region: Victoria
- Hazard: Fire
- Attribution status: NONE — no formal attribution study exists
- Impact: 173 people killed — Australia's worst peacetime bushfire death toll. Melbourne reached 46.4°C. ~400,000 ha burned; ~2,000 homes destroyed. The Victorian Bushfires Royal Commission found the disaster arose where climatic extremes met inadequate preparedness and the "stay or go" policy.
- Attribution: No formal rapid attribution study. The record heat sits within Australia's attributed warming trend, but the Royal Commission conducted no attribution.
- Citation: Victorian Bushfires Royal Commission, 2010 — http://royalcommission.vic.gov.au/Commission-Reports/Final-Report.html

#### Queensland floods (Dec 2010 – Jan 2011)

- Region: Queensland
- Hazard: Flood
- Attribution status: NONE — no formal attribution study exists
- Impact: 33 people killed; 78% of Queensland declared a disaster zone; Brisbane's CBD inundated. Nine died in the Toowoomba–Lockyer Valley "inland tsunami" on 10 January. ~A$2.38bn insured losses; A$5–7bn total.
- Attribution: No formal attribution study. A record La Niña amplified the event; flood attribution in this region remains complex.
- Citation: Queensland Floods Commission of Inquiry, 2012 — https://www.queenslandfloodscommission.qld.gov.au/

#### The Angry Summer (Sep 2012 – Feb 2013)

- Region: Australia-wide
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: September–December 2012 was Australia's hottest four-month period on record (+1.61°C). On 8 January 2013 the national area-averaged maximum reached 40.33°C, the highest ever recorded, and the Bureau extended its forecast colour scale past 54°C.
- Attribution: Climate change increased the probability of Australia's record national average temperature by at least five times.
- Citation: Lewis & Karoly 2013, GRL 40:3705–3709 — https://doi.org/10.1002/grl.50673

#### Great Barrier Reef mass bleaching (2016 & 2017) (2016 and 2017)

- Region: Queensland
- Hazard: Marine
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Back-to-back events bleached two-thirds of the Great Barrier Reef. 2016: severe bleaching on 38% of surveyed reefs, 22% reef-wide coral mortality, concentrated in the far north. 2017 hit the central third.
- Attribution: Without global warming the probability of bleaching this severe would have been close to zero.
- Citation: Hughes et al. 2017, Nature 543:373–377 — https://doi.org/10.1038/nature21707

#### Australia's hottest and driest year (2019)

- Region: Australia-wide
- Hazard: Heat
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: National mean temperature +1.52°C above the 1961–1990 average and mean maximum +2.09°C — both records broken comprehensively. Rainfall 277.6 mm, 40% below average: the driest year on record. Forest Fire Danger Index the highest since records began in 1950.
- Attribution: Driven by a record positive Indian Ocean Dipole on top of the long-term anthropogenic warming trend; established the preconditions for Black Summer.
- Citation: BoM Annual Climate Statement 2019 — https://www.bom.gov.au/climate/current/annual/aus/2019/

#### Black Summer bushfires (Jul 2019 – Mar 2020)

- Region: Eastern and southern Australia
- Hazard: Fire
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Over 24 million hectares burned (Royal Commission figure; estimates range ~18–33 Mha by method). 33 direct deaths plus an estimated 417 excess deaths from smoke (95% CI 153–680; Borchers Arriagada et al., MJA 2020) across four eastern states only, so a national undercount. ~3 billion animals killed or displaced (WWF). Over 3,000 homes lost; more than A$10bn in financial impact. Population-weighted PM2.5 peaked at 98.5 µg/m³ on 14 January 2020, over 14 times the historical mean.
- Attribution: Climate change induced at least a 30% increase in the risk of fire weather this extreme, driven mainly by temperature extremes which have become at least twice as likely. The authors call their estimate conservative because models underestimate the observed trend. No attributable trend was found in extreme annual drought.
- Citation: van Oldenborgh et al. 2021, NHESS 21:941–960 — https://doi.org/10.5194/nhess-21-941-2021
- Note: The Royal Commission that followed warned of "consecutive and compounding natural disasters" and led to the creation of the Australian Climate Service.

#### Great Barrier Reef bleaching during La Niña (Mar 2022)

- Region: Queensland
- Hazard: Marine
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: Fourth mass bleaching in seven years and the first ever recorded during a La Niña — a phase that normally brings cooler, cloudier conditions. Of 719 reefs surveyed, 91% showed some bleaching; 43% severe.
- Attribution: No single-event probability study. AIMS researchers described bleaching under La Niña as a clear sign of escalation beyond the reef's capacity to recover.
- Citation: AIMS Reef Snapshot 2021–22 — https://www.aims.gov.au/monitoring-great-barrier-reef/gbr-condition-summary-2021-22

#### Northern Rivers / Lismore floods (Feb–Mar 2022)

- Region: New South Wales
- Hazard: Flood
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: Lismore's flood peaked at ~14.4 m — more than 2 m above any previous record, surpassing 1954 and 1974. Five died in February and one in March. 3,170 of Lismore's 4,145 firms affected. Insured losses across the broader south-east Queensland and northern NSW event reached ~A$5.8bn, Australia's costliest flood insurance event.
- Attribution: WWA found climate change made the rainfall more intense, but model spread made precise quantification difficult; no peer-reviewed rapid study specific to the Lismore record has been identified.
- Citation: WWA 2022; Insurance Council of Australia — https://www.worldweatherattribution.org/

#### Australia's hottest day (13 Jan 2022)

- Region: Onslow, Western Australia
- Hazard: Heat
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: Onslow Airport reached 50.7°C, equalling the national record set at Oodnadatta in January 1960. Roebourne and Mardie both hit 50.5°C the same day. Onslow is coastal, which makes the reading more remarkable.
- Attribution: No single-day attribution study; sits within Australia's attributed +1.51°C warming since 1910.
- Citation: Bureau of Meteorology — https://www.bom.gov.au/climate/extreme/records.shtml

#### Fifth GBR bleaching & the Western Australia marine heatwave (2024 and 2025)

- Region: Queensland and Western Australia
- Hazard: Marine
- Attribution status: PARTIAL — contextual or trend attribution, or a study with wide uncertainty
- Impact: March 2024 brought the largest spatial footprint of bleaching ever recorded on the Great Barrier Reef: 73% of surveyed reefs bleached, and for the first time extreme bleaching appeared in all three regions. Heat stress in the Keppel Islands reached 12–15.5 °C-weeks, the highest ever measured on the reef. 2025 brought a sixth event, plus the worst bleaching on record for Western Australian reefs, with anomalies of +3 to +4°C off the Kimberley and first-ever mass bleaching at Rowley Shoals and the inshore Kimberley.
- Attribution: Part of the fourth global bleaching event, attributed to human-caused ocean warming with very high confidence in IPCC AR6.
- Citation: AIMS; NOAA Coral Reef Watch — https://www.aims.gov.au/monitoring-great-barrier-reef/gbr-condition-summary-2023-24

#### Tropical Cyclone Alfred (Feb–Mar 2025)

- Region: South-east Queensland
- Hazard: Storm
- Attribution status: NONE — no formal attribution study exists
- Impact: Peaked at Category 4 offshore, then crossed Moreton Island as a Category 1 around 1 am on 8 March 2025 — the first tropical cyclone to make landfall this close to Brisbane in the modern record. Widespread coastal erosion, power outages and flooding across south-east Queensland and northern NSW.
- Attribution: No formal attribution study. CSIRO and BoM report cyclone numbers in the Australian region have declined since 1982 while projecting fewer but more intense systems.
- Citation: Bureau of Meteorology — https://www.bom.gov.au/cyclone/history/Alfred2025.shtml

### Australia, 2025–26

#### Summer of climate whiplash (Nov 2025 – Mar 2026)

- Region: Victoria, South Australia, NSW
- Hazard: Compound
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Victorian fires destroyed approximately 451 homes and over 1,000 other buildings across ~450,000 hectares. On 9 January 2026 Victoria issued its first "Catastrophic" fire danger warning since Black Summer, with more than 200 fires burning. Late January brought six consecutive days with an Australian location at or above 49°C, and Port Augusta reached 50°C — the most southerly point on Earth ever to do so. Between 26 and 31 January, 62 weather stations set all-time daily maximum records. The season was Australia's 8th hottest summer (+1.1°C on 1961–1990) and its wettest in nearly a decade, 32% above average — heat and deluge in the same season.
- Attribution: The 5–10 January south-eastern heatwave was made ~5× more likely and ~1.6°C hotter by human-caused climate change. La Niña cut the event's probability by 20–45% and shaved 0.3–0.5°C off temperatures, but that cooling was overwhelmed by the warming signal. Events like this used to arrive roughly every 25 years; they now return about every five.
- Citation: WWA, 22 Jan 2026 — https://www.worldweatherattribution.org/climate-change-eclipses-la-nina-cooling-in-australia-to-drive-extreme-heatwave-and-heightened-fire-risk/
- Note: Cross-reference the Garnaut Review of 2008, which predicted on Bureau and CSIRO modelling that intensifying fire seasons "should be apparent by 2020".

### First half of 2026

#### Southern Africa floods (Dec 2025 – Jan 2026)

- Region: South Africa, Mozambique, Zimbabwe
- Hazard: Flood
- Attribution status: PENDING — too recent; assessment not yet published
- Impact: More than 200 people killed across southeastern Africa with hundreds of thousands displaced (DW, 19 Jan 2026). South Africa: at least 31 deaths across Limpopo and Mpumalanga, over 1,300 houses damaged in Mpumalanga alone, Kruger National Park evacuated; a National Disaster was declared on 18–19 January. Mozambique: over 103 deaths and more than 173,000 affected. Zimbabwe: ~70 deaths.
- Attribution: Attribution assessment pending. No rapid attribution study for this event was retrievable at the time of compilation.
- Citation: South African Government; AP News; DW — https://www.sanews.gov.za/south-africa/government-declares-national-disaster-over-flooding-severe-weather

#### Chile & Argentina fire weather (Jan–Feb 2026)

- Region: Central Chile, Patagonia
- Hazard: Fire
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Dangerous fire weather across central Chile and Argentine Patagonia during the southern summer.
- Attribution: Climate change made dangerous fire weather 3× more likely in central Chile and 2.5× more likely in Patagonia. Not yet peer-reviewed at the time of reporting.
- Citation: WWA, via Carbon Brief, 11 Feb 2026 — https://www.carbonbrief.org/climate-change-made-fire-weather-in-chile-and-argentina-three-times-more-likely

#### Record March heat in western North America (Mar 2026)

- Region: Western North America
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Record-shattering March temperatures across the region.
- Attribution: Assessed as virtually impossible without climate change, using ERA5, CPC gridded data and CMIP6 models. Full probability ratios were not retrievable from the report.
- Citation: WWA, 20 Mar 2026 — https://www.worldweatherattribution.org/record-shattering-march-temperatures-in-western-north-america-virtually-impossible-without-climate-change/

#### European June heatwave (Mid-to-late Jun 2026)

- Region: Western and central Europe
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Western Europe recorded its hottest June on record at 20.74°C, +3.06°C above the 1991–2020 June average, beating June 2025. England and France had their warmest June ever; Germany its second. EuroMOMO recorded ~14,260 excess deaths across 24 countries in the week of 22–28 June — the highest weekly June excess since monitoring began. Germany: 5,753–5,780 excess deaths in that week alone (Destatis), with the Robert Koch Institute noting more heat deaths in 2026 than the previous six years combined. France: at least 2,025 (Santé Publique France), a 36% excess described as the worst mortality rate since 2003. Belgium 1,747; England and Wales ~2,200; Spain ~610–1,033.
- Attribution: A WWA trend study (Scientific Report No. 85, June 2026) found fossil fuel emissions have rapidly worsened European heatwaves within just a few decades. For the UK specifically, an Imperial College / Met Office / LSHTM analysis attributed 59% of May heatwave deaths and 38% of June heatwave deaths to human-caused climate change. A dedicated rapid study for the June 2026 mortality event itself was not retrievable at compilation.
- Citation: WWA Report No. 85; Copernicus C3S; Carbon Brief, 17 Jul 2026 — https://www.worldweatherattribution.org/wp-content/uploads/FINAL-WWA-Scientific-Report-European-Heatwave.pdf
- Note: Excess-death figures are provisional. Heat mortality is counted weeks to months after the event, and early figures almost always rise.

#### France & Spain wildfires (Late Jun – Jul 2026)

- Region: South-west France, central Spain
- Hazard: Fire
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Fires broke out across Gironde and Landes in France and Toledo, Ávila, Madrid and Guadalajara in Spain, following months of drought and extreme heat. The EU Civil Protection Mechanism deployed aircraft and personnel.
- Attribution: Climate change increased the likelihood of the compounding drivers of severe fire conditions — chiefly exceptional heat and worsened drought. The study identifies a wet-spring-then-hot-dry-summer whiplash pattern being intensified by warming. Specific probability ratios were not fully retrievable.
- Citation: WWA, 30 Jul 2026 — https://www.worldweatherattribution.org/climate-change-increases-likelihood-of-compounding-drivers-of-severe-wildfire-conditions-in-france-and-spain/

#### Southeast Asia monsoon floods (Late Jun – Jul 2026)

- Region: Indonesia, Sri Lanka, Thailand, Bangladesh
- Hazard: Flood
- Attribution status: PENDING — too recent; assessment not yet published
- Impact: Over 1,300 deaths across the region. Sumatra alone: 708 dead and 504 missing by 5 July, with ~3.2 million affected, 2,600 injured and a million evacuated after heavy monsoon rain and a rare Malacca Strait tropical storm. Sri Lanka: 410 dead and 336 missing from Cyclone Ditwah, with the President declaring it the most challenging natural disaster in the country's history. Southern Thailand: ~181 deaths. Bangladesh: at least 51 deaths, most in Cox's Bazar, with over a million affected.
- Attribution: Attribution assessment pending. No rapid study for these events was retrievable at compilation.
- Citation: BritBrief, 5 Jul 2026; BBC, 12 Jul 2026 — https://www.bbc.com/news/articles/ce8k7e75k7go
- Note: The deadliest events of H1 2026 are also the ones without attribution studies. That asymmetry is itself a finding.

#### South Asian monsoon floods (Jul – Aug 2026)

- Region: Assam, Kerala, Afghanistan, Pakistan
- Hazard: Flood
- Attribution status: PENDING — too recent; assessment not yet published
- Impact: Ongoing at compilation. Assam: at least 82 deaths by 2 August, ~178,000 people affected across seven districts, 349 villages hit and 15,060 ha of crops submerged — described by the state minister as the worst floods in six decades. Kerala: 18 deaths, 13,496 people in 363 relief camps, over 350 mm of rain in places. India total ~92. Afghanistan and Pakistan: at least 46 deaths.
- Attribution: Attribution assessment pending.
- Citation: Times of India; The Hindu; ABC News — https://www.bbc.com/news/articles/cqlx61p3wz0o

#### FIFA World Cup humid heat (Jun–Jul 2026)

- Region: North America
- Hazard: Heat
- Attribution status: ROBUST — formal attribution study with a quantified result
- Impact: Dangerous wet-bulb globe temperatures assessed across tournament venues during the 11 June – 19 July window.
- Attribution: Climate change has significantly increased the likelihood of dangerous humid heat at World Cup venues.
- Citation: WWA, 14 May 2026 — https://www.worldweatherattribution.org/climate-change-big-player-at-fifa-world-cup-2026/

## The contrarian record

### Global Climate Coalition, 1989–2002

A 1995 internal science-committee primer, released later in litigation, explicitly accepted anthropogenic climate change and rebutted contrarian arguments one by one. That section was cut before publication; the distributed version said claims of significant human impact "seem unsubstantiated."

### ExxonMobil's internal science versus its public messaging

Supran & Oreskes 2017 (ERL, 10.1088/1748-9326/aa815f) found 83% of ExxonMobil's peer-reviewed papers acknowledged human-caused climate change against 12% of its newspaper advertorials. Supran, Rahmstorf & Oreskes 2023 (Science, 10.1126/science.abk0063) found 63–83% of the company's own projections accurate. ExxonMobil disputes the framing of both analyses.

### The hockey stick

The 2006 National Research Council review (10.17226/11676) found the core conclusion broadly correct and robust to alternative methods, while noting pre-1400 uncertainties had been conveyed too confidently. Wahl & Ammann 2007 (10.1007/s10584-006-9105-7) showed the principal-components critique did not substantively alter the reconstruction.

### "Climategate," 2009

Four inquiries followed the CRU email release. The Oxburgh panel found no scientific malpractice. The Muir Russell review found the scientists' "rigour and honesty are not in doubt" while criticising a pattern of insufficient openness on information requests. The House of Commons Science and Technology Committee found no corruption of conclusions. A Penn State inquiry cleared Michael Mann. No inquiry found data fabrication.

### The "hiatus"

Karl et al. 2015 (Science, 10.1126/science.aaa5632) corrected sea-surface and land record biases and found early-21st-century warming at least as fast as the late twentieth. Medhaug et al. 2017 (Nature, 10.1038/nature22315) showed the residual was explained by definition choices, dataset differences and natural variability. Every year from 2015 to 2025 then ranked among the eleven warmest.

## Known caveats — read before citing

- **Black Summer area burned.** The Royal Commission's official figure is "over 24 million hectares." Satellite and state-agency estimates range from roughly 18 to 33 Mha depending on which fire types, states and dates are counted. Any single figure is methodology-dependent.
- **Black Summer smoke deaths.** The peer-reviewed estimate is 417 (95% CI 153–680); a later estimate by the same group gives ~445. Both cover only four eastern states and therefore understate the national toll.
- **Derna, Libya, 2023.** Death tolls run from 4,333 (Libyan Red Crescent) to over 11,300 (UN OCHA reporting), with higher figures cited by some officials. No systematic count exists. The WWA report URL for this event no longer resolves; the "up to 50×" rainfall figure is cited via secondary sources referencing that report and should be checked against the peer-reviewed version.
- **2010 Russian heatwave.** The ~55,000 figure is a modelled excess-mortality estimate, not a registry count; credible ranges run 25,000–56,000.
- **Hurricane Maria, 2017.** 2,975 is the official recognised toll; Kishore et al. estimated 4,645. Both are methodologically defensible.
- **First Mauna Loa annual mean above 400 ppm.** The first daily reading (9 May 2013) and the 2013 global annual mean (395.3 ppm) are confirmed; the exact year the annual mean crossed 400 ppm could not be verified to a primary NOAA source.
- **Pre-1990 IPCC figures.** Some FAR, SAR and TAR headline numbers and sub-report URLs were assigned from the established archival record rather than extracted from the original Summary for Policymakers text. Verify against archive.ipcc.ch for formal citation.
- **Two omitted papers.** A 2025 Nature paper on attributing economic damages to individual emitters, and Newman & Noy on global attributable extreme-weather costs, could not be verified and were excluded rather than cited speculatively.
- **Högbom (1895–96) and Ångström (1900).** No accessible digitised originals were found; both rest on the American Institute of Physics history of climate physics as an authoritative secondary source.
- **Australian Academy of Science.** *The Science of Climate Change: Questions and Answers* exists in 2010 and 2015 editions only. The 2021 update was published under a different title, *The Risks to Australia of a 3 °C Warmer World*. There is no 2021 edition of the Q&A.
- **Australia's National Climate Risk Assessment.** The status and findings of the 2024–25 NCRA could not be verified and it is therefore not entered in the canon.
- **H1 2026 gaps.** Official July 2026 Copernicus and NOAA bulletins were unpublished at compilation; the July figure shown is a preliminary independent ERA5 estimate. Mauna Loa monthly CO2 for January–March and June 2026 was not retrieved. No IPCC AR7 progress for H1 2026 could be verified. Disaster figures derive from news reporting against named official sources rather than EM-DAT aggregation. No verified distinct West African, East African or South American H1 2026 events were retrieved beyond the Chile–Argentina fire weather study; absence of a retrieved record is not evidence that nothing occurred.

## Principal sources

- [Intergovernmental Panel on Climate Change](https://www.ipcc.ch/)
- [World Meteorological Organization](https://wmo.int/)
- [US National Academies Press / National Research Council](https://nap.nationalacademies.org/)
- [NOAA National Centers for Environmental Information](https://www.ncei.noaa.gov/)
- [NASA GISS Surface Temperature Analysis](https://data.giss.nasa.gov/gistemp/)
- [Copernicus Climate Change Service](https://climate.copernicus.eu/)
- [Met Office Hadley Centre — HadCRUT5](https://www.metoffice.gov.uk/hadobs/hadcrut5/)
- [Berkeley Earth](https://berkeleyearth.org/)
- [NOAA Global Monitoring Laboratory — Mauna Loa](https://gml.noaa.gov/ccgg/trends/)
- [World Weather Attribution](https://www.worldweatherattribution.org/)
- [CSIRO & Bureau of Meteorology — State of the Climate](https://www.csiro.au/en/research/environmental-impacts/climate-change/state-of-the-climate)
- [Australian Bureau of Meteorology](https://www.bom.gov.au/climate/)
- [Australian Institute of Marine Science](https://www.aims.gov.au/)
- [Australian Academy of Science](https://science.org.au/)
- [National Snow and Ice Data Center](https://nsidc.org/)
- [NOAA Coral Reef Watch](https://coralreefwatch.noaa.gov/)
- [Global Carbon Project](https://globalcarbonbudget.org/)
- [UNEP Emissions Gap Report](https://www.unep.org/resources/emissions-gap-report-2024)
- [US Global Change Research Program — NCA5](https://nca2023.globalchange.gov/)
- [American Institute of Physics — History of Climate Physics](https://history.aip.org/climate/)
- [EM-DAT, CRED / UCLouvain](https://www.emdat.be/)
- [UNFCCC](https://unfccc.int/)

## How to cite

*Global Code Red: The Climate Research Record, 1824–2026.* codered.global, compiled 4 August 2026.

When citing a specific finding, cite the primary source linked from that entry rather than this document. This record is an index to the literature, not a substitute for it.