Timeline of Climate Change
The science of human-caused warming, from Fourier's work in 1824 through greenhouse-gas experiments, measurements, climate models and international assessments to observations reported in 2026.
- Category
- Natural Sciences
- Events
- 24 events 1824–2026
- Generated
- by gpt-6-astra
1824: Fourier investigates Earth's heat balance
Joseph Fourier argued that Earth's temperature depended on how the atmosphere affected the exchange of heat with space. His work helped frame the planetary energy-balance problem, although it did not identify the molecular mechanism of greenhouse gases.
Wikipedia1856: Foote links carbon dioxide with warming
Eunice Newton Foote reported experiments in which sunlight warmed gases enclosed in glass cylinders and suggested that more atmospheric carbon dioxide would produce a warmer Earth. Her apparatus did not isolate infrared absorption, but her climatic inference anticipated later research.
Wikipedia1861: Tyndall publishes measurements of infrared absorption
John Tyndall published an extended study of how gases and vapors absorbed radiant heat, building on experiments begun earlier. Water vapor, carbon dioxide and other trace gases absorbed infrared radiation differently from the main components of air, establishing a physical mechanism for their climatic influence.
Wikipedia1896: Arrhenius calculates warming from additional carbon dioxide
Svante Arrhenius estimated how changes in atmospheric carbon dioxide could alter surface temperature. His calculations linked greenhouse-gas abundance with climate on a global scale, although later work revised both the methods and numerical estimates.
Wikipedia1938: Callendar connects observed warming with fossil fuels
Guy Stewart Callendar compiled temperature records and carbon dioxide measurements and argued that fuel combustion contributed to recent warming. His synthesis brought observations and greenhouse theory together when many scientists still doubted that human emissions could measurably change climate.
Wikipedia1956: Plass updates carbon dioxide absorption calculations
Gilbert Plass used improved spectroscopy and numerical calculations to assess how carbon dioxide affected outgoing infrared radiation. His work challenged arguments that overlapping absorption bands made additional carbon dioxide climatically unimportant.
Wikipedia1957: Revelle and Suess examine ocean carbon uptake
Roger Revelle and Hans Suess investigated exchanges of carbon dioxide between the ocean and atmosphere. Their work showed that ocean chemistry limited how readily seawater could absorb the carbon released by fossil-fuel use, supporting concern about atmospheric accumulation.
Wikipedia1958: Keeling begins a precise atmospheric carbon record
Charles David Keeling established high-precision carbon dioxide measurements at Mauna Loa and other sites. The resulting record separated a seasonal cycle from a persistent rise, providing direct evidence that atmospheric carbon dioxide was accumulating.
Wikipedia1967: Manabe and Wetherald model greenhouse warming
Syukuro Manabe and Richard Wetherald calculated the thermal response of an atmospheric column to changing carbon dioxide under specified humidity assumptions. Their model connected surface warming with changes aloft and helped establish quantitative climate modeling.
Wikipedia1975: Broecker warns of pronounced anthropogenic warming
Wallace Broecker published "Climatic Change: Are We on the Brink of a Pronounced Global Warming?" He argued that rising carbon dioxide would increasingly dominate natural variability, bringing the phrase global warming into wider scientific use.
Wikipedia1979: The Charney report assesses climate sensitivity
A US National Research Council study chaired by Jule Charney assessed the warming expected from doubling atmospheric carbon dioxide. Its estimated range of 1.5 to 4.5 degrees Celsius became a reference point for subsequent research on climate feedbacks.
Wikipedia1985: The Villach assessment links gases and climate risk
An international assessment meeting in Villach, Austria, examined carbon dioxide and other greenhouse gases together. Its conclusions helped move climate change from a specialist research question toward coordinated international scientific assessment.
Wikipedia1988: Hansen presents evidence of warming to Congress
James Hansen testified before the US Senate that the observed warming signal was consistent with an enhanced greenhouse effect. His testimony during a hot summer drew wide public attention to the relationship between climate measurements and human emissions.
Wikipedia1988: The Intergovernmental Panel on Climate Change forms
The World Meteorological Organization and the United Nations Environment Programme established the Intergovernmental Panel on Climate Change. The panel organized assessments of published research rather than running its own climate experiments or negotiating emissions treaties.
Wikipedia1990: The first assessment establishes a shared evidence base
The Intergovernmental Panel on Climate Change issued its First Assessment Report. It described greenhouse warming and possible future changes while noting that unequivocal detection of a human influence remained difficult against natural climate variability.
Wikipedia1995: The second assessment detects a human influence
The Intergovernmental Panel on Climate Change concluded that the balance of evidence suggested a discernible human influence on global climate. The finding reflected advances in observations and methods for distinguishing expected human effects from natural variability.
Wikipedia1999: Vostok ice extends the greenhouse-gas climate record
Researchers published an Antarctic ice-core record spanning roughly 420,000 years from Vostok. Air bubbles and ice chemistry linked greenhouse-gas changes with repeated glacial cycles, providing a long context for modern atmospheric measurements.
Wikipedia2004: An extreme heatwave receives an attribution study
Peter Stott, Dáithí Stone and Myles Allen estimated how human influence changed the likelihood of the 2003 European heatwave. The study helped establish a probabilistic approach to event attribution, rather than treating an extreme event as having only one cause.
Wikipedia2007: The fourth assessment strengthens attribution of warming
The Intergovernmental Panel on Climate Change judged that most observed warming since the mid-twentieth century was very likely due to human greenhouse-gas emissions. The assessment combined physical understanding, observations and modeling with an explicit statement of confidence.
Wikipedia2013: Mauna Loa crosses a carbon dioxide threshold
The daily mean carbon dioxide concentration measured at Mauna Loa exceeded 400 parts per million. The milestone referred to a daily reading at a specific monitoring station, not the global annual average or an instantaneous change in climate.
Wikipedia2018: A special report compares warming levels
The Intergovernmental Panel on Climate Change assessed the consequences of warming of 1.5 degrees Celsius compared with 2 degrees above preindustrial levels. It connected differences in impacts with emissions pathways and the remaining carbon budget.
Wikipedia2021: The sixth assessment establishes unequivocal human warming
The Intergovernmental Panel on Climate Change concluded that human influence had unequivocally warmed the atmosphere, ocean and land. Its physical-science assessment connected the observed changes with greenhouse-gas emissions and evaluated regional changes and extremes.
Wikipedia2024: A calendar year exceeds 1.5 degrees of warming
The Copernicus Climate Change Service estimated that the year's global mean surface air temperature was about 1.6 degrees Celsius above the 1850–1900 average. A single year above 1.5 degrees did not by itself establish that the Paris Agreement's long-term warming threshold had been crossed.
Wikipedia2026: A global assessment adds Earth's energy imbalance
The World Meteorological Organization's assessment of 2025 introduced Earth's energy imbalance as a climate indicator. It reported that the planet was gaining heat faster than it lost heat to space, alongside confirmation that 2015–2025 were the eleven warmest years in the instrumental record.
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