We like to think of climate change as something that has only recently become understood by scientists. After all, if we had known before we committed to them as our primary fuel source that burning fossil fuels would lead to disastrous consequences, then why would we continue to do it?
The answer is not just ignorance, but also greed. In this article, we will go through each of the major advances from the history of climate science to find out when we knew what we know now, and how the trailblazers of climate science made their shocking discoveries.
Carbon Dioxide – 1640
When you hear about climate change, it is always in the context of CO2 emissions. While this is certainly not the only Greenhouse Gas (GHG), nor even the most potent, it is the most relevant to human-induced climate change. That is solely down to the sheer quantity of the stuff we have released into the atmosphere.
In 1640, a Belgian alchemist by the name of Johann Baptista Van Helmont was the first to realise that the atmosphere was made up of different gases rather than just ‘air’. He named one of these gases the ‘wild spirits’, and realised that this same gas was released whether you were burning coal, burning wood, or fermenting grapes. Wild spirits, you may have guessed, turned out to be carbon dioxide.
The Greenhouse Effect – 1824
Another major breakthrough would not come for 184 years, when another four-named man with a similar first name came along. Jean-Baptiste Joseph Fourier was a French mathematician and Egyptologist. He was one of many scholars to accompany Napoleon Bonaparte on his famous ‘expedition’ to Egypt in 1798, during which the Rosetta Stone was ‘discovered’.
In 1824, Fourier had a strange realisation. He knew roughly how hot the earth’s surface was, and he knew roughly how much sun the earth gets, but these numbers did not match up. Not by a long shot. He realised there had to be something trapping heat in the earth system. Fourier speculated that it was the atmosphere itself that was keeping the heat from dissipating into space.
He compared the earth and its atmosphere to a box with a glass cover. The box heats up because the sun’s heat enters but then is unable to escape. While he didn’t use the phrase, Fourier had described the greenhouse effect. We now know that the earth would be approximately 33℃ colder than it is now without the greenhouse effect, making it uninhabitable to humans!
Greenhouse Gases Cause Climate Change – 1856
The first published work which specifically showed that varying levels of CO2 and water vapour in the atmosphere could affect global temperatures came in 1856. The author was a woman named Eunice Foote, who was largely ignored by her peers because she was a woman, an amateur and an American. Until recently, she had been all but erased from the history of climate science. She was, however, entirely correct.
Most histories of climate change credit Irish-born physicist John Tyndall with this discovery in 1859, 3 years after Foote’s paper was published. With his greater resources and experience, Tyndall was able to conduct sophisticated experiments testing each of the major gases in the atmosphere to see which of them would trap heat.
He found that the two most common gases, nitrogen and oxygen, had no effect on the storing of heat within the atmosphere, but that CO2, water vapour and ozone could have this effect. It appears that Tyndall was unaware of Foote’s work, as if he was he likely would have focused on water vapour and CO2 rather than testing nitrogen and oxygen first. However, it is also perfectly possible that he simply didn’t respect women (or Americans) enough to give credence to Foote’s work.
We have known for about 160 years that adding CO2 to the atmosphere would increase global temperatures. While Foote did not make this distinction, Tyndall even realised that incoming radiation would be re-emitted as ‘long-wave infrared’, although this phrase did not yet exist.
Fossil Fuels Release Greenhouse Gases – 1896
The next major milestone came in 1896, when Swedish scientist Svante Arrenhius discovered that burning coal releases significant amounts of carbon dioxide into the atmosphere. He even linked this release of carbon dioxide to increasing global temperatures, and predicted that the atmosphere would warm as a result of burning fossil fuels.
Arrenhius even estimated how much CO2 the ocean would be able to absorb. He also predicted that a 40% increase or decrease in atmospheric CO2 might lead to glacial advances or retreats.
So…126 years ago we basically had all the information we needed to take action. We knew that burning fossil fuels releases carbon dioxide, and that the release of carbon dioxide traps solar radiation in the earth system, leading to an increase in temperatures. However, even Arrenhius did not put two and two together. He believed that the warming resulting from burning fossil fuels would be beneficial to humanity.
The Planet is Warming – 1938
In 1938, English engineer G.S. Callendar found that CO2 levels in the atmosphere were increasing, and compared this to global temperatures. He published a paper entitled ‘The Artificial Production of Carbon Dioxide and its Influence on Temperature’. It is worth repeating the first lines of this paper here:
“Few of those familiar with the natural heat exchanges of the atmosphere, which go into the making of our climates and weather, would be prepared to admit that the activities of man could have any influence upon phenomena of so vast a scale. In the following paper, I hope to show that such influence is not only possible, but is actually occurring at the present time”.
You would think that with his advanced understanding of climate change, Callendar would have understood that it presented a problem for humanity. No such luck.:
“In conclusion, it may be said that the combustion of fossil fuel, whether it be peat from the surface or oil from 10,000 feet below, is likely to be beneficial to mankind in several ways, besides the provision of heat and power. For instance, the above mentioned small increases of mean temperature would be important at the northern margin of cultivation, and the growth of favourably situated plants is directly proportional to the carbon dioxide pressure. In any case the return of the deadly glaciers should be delayed indefinitely”.
What Callendar did not anticipate was the rate and scale at which we would burn fossil fuels over the following 84 years. He could not have predicted the advances in technology and massive population boom that would lead to such a thorough extraction of the planet’s fossil fuel reserves. He ought to have been less worried about another ice age, and more worried about the now imminent age of ice-free poles. What he did predict, however, was that a doubling of CO2 levels in the atmosphere would lead to a 2℃ increase in global mean temperature.
This number is commonly referred to as the Equilibrium Climate Sensitivity (ECS) of the earth system and is still used today. Unfortunately, it is a bit higher than Callendar thought. It is now estimated that a doubling of CO2 in the atmosphere will lead to between 2.6 and 4.1℃ of warming, with the best estimate being around 3℃ or a little higher. Still, not too shabby for 1938!
Climate Science Enters the Public Eye – 1988
In 1988, a scientist by the name of James Hansen testified to the US congress that climate change was now an urgent problem. His clear and urgent message made him an icon of the environmentalist movement, not just for his work on the science of climate change, but also for his recognition that scientists have a responsibility to communicate the importance of climate change to the public.
By this time, it can be said that greed was now the primary reason for inaction rather than ignorance. The science was there, and it had been effectively communicated to the US government in a prescient testimony that was widely covered by the world media. Fossil fuel corporations and lobby groups now stepped up to the plate to replace ignorance as the major barrier to climate action.
For a full breakdown of what these companies did to spread misinformation, see ‘The Climate Deception Dossiers’. This document, released by the Union of Concerned Scientists, lays out the many ways fossil fuel companies sowed doubt about climate change. One particularly shocking line from a strategy memo by the American Petroleum Institute states that ““victory” would be achieved for the campaign when “average citizens” and the media were convinced of “uncertainties” in climate science”. It does not get much more clear than that.
Hansen’s testimony led George Bush Sr. to vow to use the ‘White House Effect’ to combat the greenhouse effect. In fairness to Bush, it was during his presidency that the US became one of the founding members of the United Nations Framework Convention on Climate Change (UNFCCC – commonly referred to as U-N-F triple C), a body that remains hugely important in guiding climate action to this day. That said, his record was far from spotless.
The IPCC is Formed – 1988
The year of Hansen’s seminal testimony also saw the formation of the Intergovernmental Panel on Climate Change (IPCC). This body has released reports every few years ever since updating the world on the current state of climate science as new research is conducted. The 6th and most recent report came in 2022, and is widely considered to be the last IPCC report that will be released while we still have time to avert climate catastrophe.
The 6th IPCC report was once again a dire warning that humanity is fast approaching the turning point at which catastrophic climate change will become unavoidable. We have already locked in serious climate impacts, but this report makes clear that things could get far far worse. No matter what, we will be feeling the effects of climate change for decades or even centuries to come. The question now becomes how severe the climate change impacts will be.
The history of climate science can be seen as the gradual realisation of the severity of this crisis. The science, however, has moved at a faster pace than the response. Governments and ordinary people have remained detached from the science, due in part to poor communication on the part of scientists and in part to an unwillingness to accept that the way we have done things for hundreds of years could be leading us down an extremely dangerous path from which we may never return.
Recognising the achievements of the researchers who have opened our eyes to the changing climate is the first step towards paying the appropriate respect to their work and to the climate system itself. We are small as individuals, but as a collective we can have a huge influence on phenomena on a vast scale. While this is the root of this crisis, it can also be the root of the solution.
Callendar – https://www.rmets.org/sites/default/files/qjcallender38.pdf
Climate Deception Dossiers – https://www.ucsusa.org/sites/default/files/attach/2015/07/The-Climate-Deception-Dossiers.pdf
ECS – https://www.weforum.org/agenda/2020/07/climate-change-equilibrium-climate-sensitivity-global-warming/#:~:text=Likely%20range%20of%20Equilibrium%20Climate,it%20is%20above%204.5C.
UCAR – https://scied.ucar.edu/learning-zone/how-climate-works/history-climate-science-research
Fourier – http://www.easterbrook.ca/steve/2017/03/the-discovery-of-the-greenhouse-effect/
Fourier – http://mpe.dimacs.rutgers.edu/2013/01/19/the-discovery-of-global-warming/
Foote – https://blogs.scientificamerican.com/voices/the-hidden-figure-in-climate-science/
Hansen – https://grist.org/article/james-hansens-legacy-scientists-reflect-on-climate-change-in-1988-2018-and-2048/
Hansen 2 – https://news.climate.columbia.edu/2018/06/26/james-hansens-climate-warning-30-years-later/
IPCC – https://www.ipcc.ch/site/assets/uploads/2018/03/ar4-wg1-chapter1.pdf
Van Helmont – https://www.britannica.com/summary/Jan-Baptista-van-Helmont
Header Image Credit: Michal Jarmoluk from Pixabay