Out of the cold: the slow beginnings of climate change science

Remembering theories about the Earth’s temperature sketched out by French mathematician and physicist Joseph Fourier a few decades before – that the Earth is surrounded by an insulating blanket of gases, what we now understand as the ‘greenhouse effect’ – Foote concluded, almost in passing: “An atmosphere of that gas would give to our Earth a high temperature.”

Later that year, her findings were presented at a meeting of the American Association for the Advancement of Science (AAAS), and were published in the American Journal of Science and Arts. The work was also cited in a write up of the AAAS meeting by Scientific American, albeit under the dismissive heading ‘Scientific Ladies’, and Foote garnered mentions in the New-York Daily Tribune as well as Canadian, Scottish and German journals. It sparkled for a time, but her work was quickly forgotten.

Lost visionary

In fact, Foote was so thoroughly forgotten that when Irish physicist John Tyndall made similar points in 1859 based on his own experiments at the Royal Institution, London, he didn’t cite her. As Tyndall’s biographer Roland Jackson points out, it’s perhaps more striking that no one else seems to have thought to send Tyndall a copy of Foote’s work in response. Jackson has pored through Tyndall’s correspondence to find any reference to someone saying a comment along the lines of “You might enjoy this similar work by one Eunice Foote”, to no avail. Instead, Tyndall is the name celebrated as a great-grandfather of modern climate science – a major, multi-university climate research centre is named after him.

Meanwhile, Foote’s work was completely lost until 2010 when retired geologist Ray Sorenson spotted it in journal archives. Then, the story of a female scientist who spoke of a warming climate back in the 1850s (and was largely ignored) hit a nerve.

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Today, it is tempting to see Foote as a great visionary, whose potentially invaluable findings were hidden by the sexism of history. There is some truth to this, but it’s important to remember that neither Foote nor Tyndall had our modern understanding of an emerging climate crisis. They weren’t worried by what they found, nor did they link the Industrial Revolution happening around them to their studies of heat and gases. It would be several decades before scientists realised that burning fossil fuels might add enough carbon dioxide to the air to cause climate change; then several decades more before it was established that this wasn’t just an abstract worry for the future, but already happening.

With the advantages of modern science, we now know that by the 1850s the combination of culling trees to clear land for agriculture and the burning of fossil fuels meant climate change was underway in the 19th century. The Earth was already warming under Foote’s feet. People at the time had no idea. Tyndall had started his scientific career working on the railways, writing movingly about the huge shifts to the landscape due to industrialisation, and yet still the idea that humans could do something as huge as change the Earth’s climate was out of reach to him.

For most people, it would have seemed quite ludicrous.

Fear of falling

Only at the end of that century did scientists connect the ever-increasing quantities of coal being burned with the possibility of global warming. A Swedish scientist named Svante Arrhenius – who, incidentally, is a distant relative of the young climate activist Greta Thunberg – had been arguing over the causes of ice ages at the Stockholm Physics Society and picked up Fourier and Tyndall’s works to see if he had something to add to the conversation.

But like many of his contemporaries, Arrhenius was actually more worried that temperatures would fall rather than rise, so he started by studying the impact of halving the amount of carbon dioxide in the air. It would, he found, cool the world by as much as 5°C, enough to bring on another ice age. A colleague suggested he might consider it the other way around, too: what if carbon dioxide was added? He ran the maths again and calculated that a doubling of atmospheric carbon dioxide would raise the Earth’s temperature by 5°C or even 6°C.

Arrhenius presented a paper at the Royal Swedish Academy of Sciences at the end of 1895, and the following spring it was translated into English in the Philosophical Magazine, which meant his findings made their way to Britain and the United States. Right at the end of the century, in 1899, another colleague pointed out that if people kept burning coal at current rates, there might be a doubling of atmospheric carbon dioxide sometime soon, at least in a few centuries. Arrhenius included this observation in his 1908 popular science book Worlds in the Making, noting that “The slight percentage of carbonic acid in the atmosphere may by the advances of industry be changed to a noticeable degree in the course of a few centuries.”

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Still, he wasn’t too worried. If anything, the notion of a warmer Earth seemed quite pleasant. The obvious joke to crack here is that he was Swedish, after all. More to the point, access to warmth would have been much more scarce than today, even in rich countries. Heat was a literal life saver (as it continues to be, despite our greater awareness of how its power can hurt, destroy and kill).

Plus, no one had run the research to unpick how a warming climate could mess with ecosystems or increase the likelihood of extreme weather. When Popular Mechanics magazine picked up Arrhenius’ findings in 1912 it mused that future generations would look back on the rise of coal and thank their ancestors for “milder breezes” and the chance to “live under sunnier skies”. It’s awkward, if not slightly painful, to read such attitudes now, but at the time it made sense.

Sceptics and deniers

From then on, a few scientists picked up the idea, while other lab work seemed to refute the research, allowing other scientists to argue convincingly that the oceans would soak up the carbon, or that volcanic dust was the main problem, or that clouds would reflect the sunlight back into space. Thomas Chrowder Chamberlin, an American geologist who had initially been excited by this area of research, would go on to repeat how sorry he was for ever being taken in by the carbon dioxide theory of global warming. He was not alone, as most scientists turned their back on it.

Yet the idea just wouldn’t go away. In 1938, a steam engineer who enjoyed a bit of weather mathematics on the side, Guy Callendar, took a paper entitled ‘The artificial production of carbon dioxide and its influence on temperature’ to the Royal Meteorological Society in London. He had calculated that since the end of the 19th century, humans had added 150,000 million tonnes of carbon dioxide to the atmosphere through the burning of fossil fuels, causing about a third of a degree of warming.

Guy Callendar calculated that since the end of the 19th century, humans had added 150,000 million tonnes of carbon dioxide to the atmosphere through the burning of fossil fuels, causing about a third of a degree of warming

Modern climate scientists reckon he was pretty much spot on. In 1938, he was laughed out of the room – politely and in a posh British scientist way, but the upshot was that the idea was dismissed once again.

Like those before him, Callendar was not too worried about it. His day job was in fossil fuels and he appreciated their power, seeing coal and its various warming powers as largely for the good. From his point of view, it would save the world from an ice age; what’s more, all that carbon dioxide might be good for plants.

The inescapable problem for those who dismissed carbon dioxide’s role in warming the planet was that the weather did keep getting hotter. There had been some media coverage of Arrenhius’s work in 1912 after a heatwave had provoked a journalist to dig into the weather records, where he realised that, yes, it really was unusually hot, and not just a matter of old men complaining that winters weren’t like they used to be.

Scientists measuring the ice caps established they were shrinking at a surprising rate and as the US and Soviet Union circled around the Cold War, the Arctic became freshly important as a possible battleground. Such military concerns presented opportunities for scientists, as did talk of weaponising the weather. There were new techniques and equipment, like computers and carbon dating, and money to try them out.

In 1957, just over a century after Eunice Newton Foote’s important findings, a global project was agreed - the International Geophysical Year - to use science and work together to study our home planet. This included exciting research possibilities, like satellite launches. The American oceanographer Roger Revelle was also asked to testify in Congress and mentioned, almost in passing, the huge quantities of carbon dioxide that were being emitted via the burning of fossil fuels.

By warning that this amounted to a giant “geophysical experiment” on the Earth, one that should be studied, he successfully lobbied for funding for a new project in Hawaii. Run by Charles Keeling, it would track atmospheric carbon dioxide, and within a decade Revelle, Keeling and their teams were establishing the concern over carbon emissions into US science policy.

Soon, the first international conference on the topic had been called, engaging ecologists who added a new layer of caution to the debate. Modern climate science had finally begun.

Dr Alice Bell is a climate policy specialist based in London and the author of Our Biggest Experiment: A History of the Climate Crisis (Bloomsbury Sigma, 2021)

This article was first published in the November 2022 issue of BBC History Revealed