When, in the early 1930s, Roger Revelle explored carbon dioxide in seawater as part of his PhD, he probably didn’t imagine the political hot potato he was handling.
Born in Seattle in 1909, Revelle grew up in a middle class family in Pasadena, California. He was identified as ‘clever’ at an early age, even included in Stanford psychologist Lewis Terman’s study of children with high IQ. When he started college, he’d planned on journalism, but soon switched to geology. In 1931 he took up a post as research assistant in oceanography at the Scripps Institute of Oceanography in La Jolla, California. Because oceanography is awesome, this meant he got to go on loads of boats out into the Pacific ocean and do a PhD on stuff he found there (yes, I am still bitter my high school science teacher failed to tell us how awesome oceanography is).
In 1931 he also married Ellen Virginia Clark, grandniece of Ellen Browning Scripps, who’d been key to establishing the oceanography institute (I’m mainly saying this so I can also tell you to look up Ellen Scripps, because she’s super-interesting).
Being the age he was, by the 1940s, Revelle got pulled into the war. Despite his flat feet, the Navy took him on and he ended up reaching rank of Commander. He also acted as a key liaison with military research, ended played a key role in shaping research priorities, both during the war and as it ended, being moved back to DC to work for the Office of Naval Research when Japan surrendered. In 1946, he was assigned to the first postwar atomic test at Bikini Atoll, studying the environmental effects of the bomb.
Fast forward to the mid-1950s, and Revelle was Director of Scripps - out of the Navy, but still taking a lot finding from them. Racelle was the sort to enjoy puzzling over a range of different topics at once, and sounds like an exciting time. As Revelle put it in a 1989 speech: “In those heady days of the 1950s one could hardly go to sea without making an important, unanticipated discovery.”
One of the questions interesting Revelle was what we might call the age of the ocean. If a bit of seawater absorbed something or another, how long would it take for that bit of water to mix through? Oceans being pretty massive, people thought that second stage might take a while. But they didn't really know. Thousands of years? Less? Was there “fossil water” that had been around even longer? If we assumed that loads of the carbon dioxide the industrial revolution was belching out was simply being absorbed by the sea (as many people did at the time) how long did that take?
Enter the new whizzy new techniques being developed around a radioactive form of carbon, carbon-14, which could be used to work out how old things are. So-called “carbon dating” was useful to archaeology, and there were medical applications, but research in the topic could rely on generous support from the military too. A chap called Hans Suess picked up these new techniques and, working with the National Park Service, applied it to the rings in old trees. He figured it'd be interesting to explore how carbon travelled through the planet, and funders were keen to let him if it meant they could learn more about carbon-14.
Revelle spotted Suess’ work, and invited him to Scripps to apply it to the sea. They worked out that a carbon dioxide molecule would hang around the atmosphere for around 10 years before surface water would pick it up, and then the oceans would take a few hundred years to turn over. So it wasn’t exactly a speedy carbon extraction, but from where they were sitting, this seemed fast enough to swallow up all the extra CO2 humans were pumping out. In 1957. They started to prepare a paper on the subject for an oceanography journal.
And yet there was still that work from Guy Callender, suggesting the carbon dioxide in the atmosphere was going up, that it wasn’t being absorbed by the oceans. Had they just miscalculated how much carbon the forests were dealing with, or were they getting something wrong with the sea calculations? Revelle knew from his PhD and the research he’d done at Bikini Atoll that seawater was very sensitive to change. Yeah, the sea would swallow up all that carbon dioxide we’re pumping out at it, but then it’ll regulate itself to avoid getting too acidic, and split a load back out again at us. This wasn't new chemistry, but it hadn't been applied to this question before.
Or, to put it another way, the idea that we could just keep pumping carbon dioxide out in the atmosphere because the seas would soak it up was dead in the water (or, rather, not dead in the water, that being the problem...). It was one of the key “oh shit” moments in the history of climate science.
Revelle added a note on this in his paper with Suess, but it doesn’t seem to have entirely seeped in yet. As Spencer Weart describes in his book the Discovery of Global Warming, it is literally taped on: “The incongruity of the paragraph had already been clear to me on repeated readings of the published paper, but it was gratifying confirmation to find the paragraph [in archives] typed on a different kind of paper and taped onto the earlier version.”
By way of conclusion, Revelle also noted that "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." It’s a line that has haunted a lot of climate policy since.
Moreover, he highlighted there’d be an opportunity with the International Geophysical Year to study this issue more. He also spoke in Congress in 1956 and 1957 about the issue, lobbying for funds. Revelle was then key to recruiting Charles David Keeling to measure carbon dioxide in the atmosphere, and getting him his first swathe of funding. That research project is still running, and has been crucial to our current knowledge of global warming (there’s a whole other post about that if you want to read about Dr Keeling and his curve).
Revelle actively raised the issue of carbon dioxide and global warming with politicians and the media throughout the latter decades of the 20th century. He was also, infamously, the guy who taught Al Gore Jr about climate change, after Gore took a class from Revelle at college. Perhaps for this reason, his memory has been used in a fair bit of skeptic vs. activist football.
In November 1990, when he received the National Medal of Science from the first President George Bush, we reportedly remarked: "I got it for being the grandfather of the greenhouse effect." A I’m not sure grandfather is the right word. We’d have to go back a lot further for that title – Arrhenius maybe, or Fourier. Midwife might be a better description.
He died in 1991 aged 82, in a medical centre he'd co-founded.