Climate Science

1824 – ongoing47 items

climatescience
Mauna Loa Observatory, Hawaii, where the Keeling Curve has been measured since 1958, with Mauna Kea behind, 2004. Photo: Forrest M. Mims III, NOAA Photo Library. Public domain, via Wikimedia Commons.
Mauna Loa Observatory, Hawaii, where the Keeling Curve has been measured since 1958, with Mauna Kea behind, 2004. Photo: Forrest M. Mims III, NOAA Photo Library. Public domain, via Wikimedia Commons.

Two centuries of climate science

In 1824 Joseph Fourier asked why the Earth is as warm as it is. The answer, gases that let sunlight in and hold heat back, was worked out over the next 130 years by a handful of physicists, one of them a woman in upstate New York. From 1958 it was measured on a Hawaiian volcano, and from 1988 it was assessed by the IPCC and argued over by the world’s governments.

How it is laid out

  • Until 1988 it is a chain of discoveries: each item is a paper or a measurement the next one builds on.

  • From 1988 the bands are the IPCC’s assessment cycles and the Kyoto Protocol’s commitment periods, with the treaties and summits set against them.

  • The last items are the records: carbon dioxide at Mauna Loa, and global temperature since 2023.

Filter by carbon dioxide, climate models (how much a doubling of CO₂ warms the world), temperature, ipcc or diplomacy to follow one thread.

Concentrations are in parts per million (ppm) of dry air. Warming is given in °C above pre-industrial, meaning the 1850–1900 average the IPCC uses, with the dataset and the year each figure applies to. Dates are Gregorian.

Human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future. — Roger Revelle and Hans Suess, 1957

Items

  1. The greenhouse on paper

    72 years

  2. Fourier: the atmosphere keeps the Earth warm

  3. Eunice Foote: carbonic acid gas traps the Sun’s heat

    Albany, New York

  4. Tyndall measures heat absorbed by gases

    Royal Institution, 21 Albemarle Street, London

  5. Arrhenius calculates the warming from doubled CO₂

  6. A theory set aside

    ≈ 56 years

  7. Ångström’s objection

  8. Callendar links fuel, CO₂ and a warming world

  9. Plass: the saturation argument fails

  10. Measuring the rise

    ≈ 31 years

  11. Revelle and Suess: a “geophysical experiment”

    Scripps Institution of Oceanography, La Jolla

  12. International Geophysical Year

    ≈ 1 year, 6 months

  13. Keeling starts measuring CO₂ at Mauna Loa

    Mauna Loa Observatory, Hawaii

  14. Manabe and Wetherald’s model

  15. Broecker asks about “global warming”

  16. The Charney report

    Woods Hole, Massachusetts

  17. Villach conference

    Villach, Austria

  18. Vostok ice core: CO₂ and temperature move together

    Vostok Station, Antarctica

  19. Hansen tells the Senate the warming has begun

    Dirksen Senate Office Building, Washington

  20. IPCC First Assessment (FAR)

    ≈ 1 year, 9 months

  21. The IPCC meets for the first time

    Geneva

  22. IPCC Second Assessment (SAR)

    ≈ 3 years, 5 months

  23. The climate convention is signed at the Earth Summit

    Riocentro, Rio de Janeiro

  24. IPCC Third Assessment (TAR)

    ≈ 4 years, 2 months

  25. Kyoto Protocol adopted

    Kyoto International Conference Center

  26. The hockey stick

  27. IPCC Fourth Assessment (AR4)

    ≈ 5 years, 4 months

  28. Nobel Peace Prize for the IPCC and Al Gore

    Oslo City Hall

  29. IPCC Fifth Assessment (AR5)

    ≈ 6 years, 4 months

  30. Kyoto: first commitment period

    ≈ 5 years

  31. Copenhagen Accord

    Bella Center, Copenhagen

  32. Kyoto: second commitment period

    ≈ 8 years

  33. Mauna Loa passes 400 ppm

    Mauna Loa Observatory, Hawaii

  34. IPCC Sixth Assessment (AR6)

    ≈ 7 years, 8 months

  35. Paris Agreement adopted

    Paris–Le Bourget exhibition centre

  36. IPCC special report on 1.5 °C

    Songdo Convensia, Incheon

  37. United States outside the Paris Agreement

    3 months, 17 days

  38. IPCC: human influence is “unequivocal”

  39. Nobel Prize in Physics for climate modelling

    Royal Swedish Academy of Sciences, Stockholm

  40. Mauna Loa erupts and cuts off the observatory

    Mauna Loa Observatory, Hawaii

  41. 2023: the warmest year on record

  42. COP28 names fossil fuels

    Expo City Dubai

  43. 2024: the first year above 1.5 °C

  44. The hottest day measured

  45. Mauna Loa peaks above 430 ppm

    Mauna Loa Observatory, Hawaii

  46. 2025: third warmest, and three years above 1.5 °C

  47. The United States leaves the Paris Agreement again