Climate Change Timeline

July 7, 2012, 6:34 pm

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This article was originally published by the American Institute of Physics and {C}Spencer Weart as Timeline of Milestones. The original version contains detailed references and links to additional information on the history of climate change science.



  • Joseph Fourier calculates that the Earth would be far colder if it lacked an atmosphere.


  • Tyndall discovers that some gases block infrared {C}radiation. He suggests that changes in the concentration of the gases could bring climate change.



  • Chamberlin produces a model for global carbon exchange including feedbacks.


  • Second Industrial Revolution. Fertilizers and other chemicals, electricity, and public health further accelerate growth.


  • World War I; governments learn to mobilize and control industrial societies.


  • Opening of Texas and Persian Gulf oil fields inaugurates era of cheap energy.


  • Global warming trend since late 19th century reported.
  • Milankovitch proposes orbital changes as the cause of ice ages.



  • World War II. Grand strategy is largely driven by a struggle to control oil fields.


  • US Office of Naval Research begins generous funding of many fields of science, some of which happen to be useful for understanding climate change.


  • Ewing and Donn offer a feedback model for quick ice age onset.
  • Phillips produces a somewhat realistic computer model of the global atmosphere.
  • Plass calculates that adding CO2 to the atmosphere will have a significant effect on the {C}radiation balance.


  • Launch of Soviet Sputnik satellite. Cold War concerns support 1957-58 International Geophysical Year, bringing new funding and coordination to {C}climate studies.
  • Revelle finds that CO2 produced by humans will not be readily absorbed by the {C}oceans.


  • Telescope studies show a greenhouse effect raises temperature of the atmosphere of Venus far above the boiling point of water.


  • Downturn of global temperatures since the early 1940s is reported.
  • Keeling accurately measures CO2 in the Earth's atmosphere and detects an annual rise. The level is 315 ppm. Mean global temperature (five-year average) is 13.9°C.


  • Cuban Missile Crisis, peak of the Cold War.


  • Calculations suggest that feedback with water vapor could make the climate acutely sensitive to changes in CO2 level.


  • Boulder, Colo. meeting on causes of climate change: Lorenz and others point out the chaotic nature of climate system and the possibility of sudden shifts.


  • Emiliani's analysis of deep-sea cores shows the timing of ice ages was set by small orbital shifts, suggesting that the climate system is sensitive to small changes.


  • International Global Atmospheric Research Program established, mainly to gather data for better short-range weather prediction, but including {C}climate.
  • Manabe and Wetherald make a convincing calculation that doubling CO2 would raise world temperatures a couple of degrees.


  • Studies suggest a possibility of collapse of Antarctic ice sheets, which would raise sea levels catastrophically.


  • Astronauts walk on the Moon, and people perceive the Earth as a fragile whole.
  • Budyko and Sellers present models of catastrophic ice-albedo feedbacks.
  • Nimbus III satellite begins to provide comprehensive global atmospheric temperature measurements.


  • {C}First Earth Day. Environmental movement attains strong influence, spreads concern about global degradation.
  • Creation of US National Oceanic and Atmospheric Administration, the world's leading funder of climate research.
  • Aerosols from human activity are shown to be increasing swiftly. Bryson claims they counteract global warming and may bring serious cooling.


  • SMIC conference of leading scientists reports a danger of rapid and serious global change caused by humans, calls for an organized research effort.
  • Mariner 9 spacecraft finds a great dust storm warming the atmosphere of Mars, plus indications of a radically different climate in the past .


  • Ice cores and other evidence show big climate shifts in the past between relatively stable modes in the space of a thousand years or so, especially around 11,000 years ago.


  • Oil embargo and price rise bring first "energy crisis".


  • Serious droughts and other unusual weather since 1972 increase scientific and public concern about climate change, with cooling from aerosols suspected to be as likely as warming; journalists talk of ice age.


  • Concern about environmental effects of airplanes leads to investigations of trace gases in the stratosphere and discovery of danger to ozone layer.
  • Manabe and collaborators produce complex but plausible computer models which show a temperature rise of several degrees for doubled CO2.


  • Studies show that CFCs (1975) and also methane and ozone (1976) can make a serious contribution to the greenhouse effect.
  • Deep-sea cores show a dominating influence from 100,000-year Milankovitch orbital changes, emphasizing the role of feedbacks.
  • Deforestation and other ecosystem changes are recognized as major factors in the future of the climate.
  • Eddy shows that there were prolonged periods without sunspots in past centuries, corresponding to cold periods.


  • Scientific opinion tends to converge on global warming, not cooling, as the chief climate risk in next century.


  • Attempts to coordinate climate research in US end with an inadequate National Climate Program Act, accompanied by rapid but temporary growth in funding.


  • Second oil "energy crisis." Strengthened environmental movement encourages renewable energy sources, inhibits nuclear energy growth.
  • US National Academy of Sciences report finds it highly credible that doubling CO2 will bring 1.5-4.5°C global warming.
  • World Climate Research Programme launched to coordinate international research.


  • Election of Reagan brings backlash against environmental movement to power. Political conservatism is linked to skepticism about global warming.
  • IBM Personal Computer introduced. Advanced economies are increasingly delinked from energy.
  • Hansen and others show that sulfate aerosols can significantly cool the climate, raising confidence in models showing future greenhouse warming.
  • Some scientists predict greenhouse warming "signal" should be visible by about the year 2000.


  • Greenland ice cores reveal drastic temperature oscillations in the space of a century in the distant past.
  • Strong global warming since mid-1970s is reported, with 1981 the warmest year on record.


  • Reports from US National Academy of Sciences and Environmental Protection Agency spark conflict, as greenhouse warming becomes prominent in mainstream politics.


  • Ramanathan and collaborators announce that methane and other trace gases together could bring as much global warming as CO2 itself.
  • Villach conference declares consensus among experts that some global warming seems inevitable, calls on governments to consider international agreements to restrict emissions.
  • Antarctic ice cores show that CO2 and temperature went up and down together through past ice ages, pointing to powerful biological and geochemical feedbacks.
  • Broecker speculates that a reorganization of North Atlantic Ocean circulation can bring swift and radical climate change.


  • Montreal Protocol of the Vienna Convention imposes international restrictions on emission of ozone-destroying gases.


  • News media coverage of global warming leaps upward following record heat and droughts plus testimony by Hansen.
  • Toronto conference calls for strict, specific limits on greenhouse gas emissions; UK Prime Minister Thatcher is first major leader to call for action.
  • Ice-core and biology studies confirm living ecosystems give climate feedback by way of methane, which could accelerate global warming.
  • Intergovernmental Panel on Climate Change (IPCC) is established.


  • Fossil-fuel and other industries form Global Climate Coalition in US to lobby politicians and convince the media and public that climate science is too uncertain to justify action.


  • First IPCC report says world has been warming and future warming seems likely. Industry lobbyists and some scientists dispute the tentative conclusions.


  • Mt. Pinatubo explodes; Hansen predicts cooling pattern, verifying (by 1995) computer models of aerosol effects.
  • Global warming skeptics emphasize studies indicating that a significant part of 20th-century temperature changes were due to solar influences. (The correlation would fail in the following decade.)
  • Studies from 55 million years ago show possibility of eruption of methane from the seabed with enormous self-sustained warming.



  • Greenland ice cores suggest that great climate changes (at least on a regional scale) can occur in the space of a single decade.


  • Second IPCC report detects "signature" of human-caused greenhouse effect warming, declares that serious warming is likely in the coming century.
  • Reports of the breaking up of Antarctic ice shelves and other signs of actual current warming in polar regions begin affecting public opinion.


  • Toyota introduces Prius in Japan, first mass-market electric hybrid car; swift progress in large wind turbines and other energy alternatives.
  • International conference produces Kyoto Protocol, setting targets to reduce greenhouse gas emissions if enough nations sign onto a treaty.


  • "Super El Niño" causes weather disasters and warmest year on record (approximately matched by 2005 and 2007). Borehole data confirm extraordinary warming trend.
  • Qualms about arbitrariness in computer models diminish as teams model ice-age climate and dispense with special adjustments to reproduce current climate.


  • Ramanathan detects massive "brown cloud" of aerosols from South Asia.


  • Global Climate Coalition dissolves as many corporations grapple with threat of warming, but oil lobby convinces US administration to deny problem.
  • Variety of studies emphasize variability and importance of biological feedbacks in carbon cycle, liable to accelerate warming.


  • Third IPCC report states baldly that global warming, unprecedented since end of last ice age, is "very likely," with possible severe surprises. Effective end of debate among all but a few scientists.
  • Bonn meeting, with participation of most countries but not US, develops mechanisms for working towards Kyoto targets.
  • National Academy panel sees a "paradigm shift" in scientific recognition of the risk of abrupt climate change (decade-scale).
  • Warming observed in ocean basins; match with computer models gives a clear signature of greenhouse effect warming.


  • Studies find surprisingly strong "global dimming," due to pollution, has retarded arrival of greenhouse warming, but dimming is now decreasing.


  • Numerous observations raise concern that collapse of ice sheets (West Antarctica, Greenland) can raise sea levels faster than most had believed.
  • Deadly summer heat wave in Europe accelerates divergence between European and US public opinion.


  • In controversy over temperature data covering past millenium, most conclude climate variations were substantial, but not comparable to post-1980 warming.
  • First major books, movie and art work featuring global warming appear.


  • Kyoto treaty goes into effect, signed by major industrial nations except US. Work to retard emissions accelerates in Japan, Western Europe, US regional governments and corporations.
  • Hurricane Katrina and other major tropical storms spur debate over impact of global warming on storm intensity.


  • Fourth IPCC report warns that serious effects of warming have become evident; cost of reducing emissions would be far less than the damage they will cause.
  • Level of CO2 in the atmosphere reaches 382 ppm. Mean global temperature (five-year average) is 14.5°C, the warmest in hundreds, perhaps thousands of years.


Weart, S., & Physics, A. (2012). Climate Change Timeline. Retrieved from


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