Sixty years ago, on this day, November 23rd 1965, American scientist Walter Orr Roberts gave a speech. In it, this –
“Perhaps, through this mechanism, we are already modifying the atmosphere, unknowingly and on a large scale, as we clearly are already doing on the city scale. Indeed, can we be sure that city-scale modification is simply city-scale? Or are the atmospheric solids and gases put in over the city bringing changes on a larger scale? The relative abundance of carbon dioxide is clearly rising in the atmosphere, almost certainly through man’s intervention. But no one seems at all secure about what this is doing to the climate.”
Bulletin of the American Meteorological Society Vol. 47, No. 3, March 1966 Based on an address delivered at the International Symposium on Electromagnetic Sensing of the Earth from Satellites, Miami, Fla., 23 November 1965.
The amount of carbon dioxide in the air was 320ppm. As of 2025, when this post was published, it was 430ppm. This matters because the more carbon dioxide in the air, the more heat gets trapped. The more heat, the more extreme weather events. You can make it more complicated than that if you want, but really, it’s not. Fwiw, I have a tattoo of the Keeling Curve on my left forearm.
The broader context was since the early 1950s the question of carbon dioxide build-up and its possible climatic consequences had been known. Not necessarily taken seriously, but by the mid-1960s, this was -just- beginning to shift.
The specific context was Roberts gave his speech in the aftermath of the release of the PSAC report on November 7th 1965.
What I think we can learn from this – it wasn’t secret or arcane information. I am not saying “everyone knew” but, well, a lot of people did.
What happened next – the emissions kept climbing. NCAR kept investigating.
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
Sixteen years ago, on this day, November 17th, ,2009 email hack at the Climatic Research Unit of University of East Anglia.
“Early on the morning of November 17, Gavin Schmidt sat down at his computer and entered his password. It didn’t work. Strange, he thought. He tried a few other accounts and none of them worked, either. Now he was alarmed. As a leading climatologist with NASA’s Goddard Institute in Manhattan, he’d been hacked before. He was used to e-mails from people who disapproved of his work,
The amount of carbon dioxide in the air was 387ppm. As of 2025, when this post was published, it is 430ppm. This matters because the more carbon dioxide in the air, the more heat gets trapped. The more heat, the more extreme weather events. You can make it more complicated than that if you want, but really, it’s not. Fwiw, I have a tattoo of the Keeling Curve on my left forearm.
The broader context was that scientists doing “impact science” work on climate had been attacked, smeared and intimidated since 1989 (e.g. hatchet jobs on James Hansen). It had hit an early peak in 1994-5 when the IPCC’s second assessment report was underway. It had continued against Michael Mann for the “hockey stick”.
The specific context was the Copenhagen climate sumit was about to start – and those opposed to action were going to do absolutely anything they could to reduce the chances of progress (the chances were vanishingly low, btw).
What I think we can learn from this – we should see this attack as part of a longer trend.
What happened next – there were various investigations and it was deemed a “nothing burger” – except the denialists, obvs, cried ‘cover-up’.
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
Fifty-nine years ago, on this day, November 2nd, 1966, Manabe and Weatherald’s pivotal paper was submitted
“According to our estimate, a doubling of the CO2 content in the atmosphere has the effect of raising the temperature of the atmosphere (whose relative humidity is fixed) by about 2C. Our model does not have the extreme sensitivity of atmospheric temperature to changes of CO2 content which was adduced by Möller.”
The amount of carbon dioxide in the air was 321ppm. As of 2025, when this post was published, it is 430ppm. This matters because the more carbon dioxide in the air, the more heat gets trapped. The more heat, the more extreme weather events. You can make it more complicated than that if you want, but really, it’s not. Fwiw, I have a tattoo of the Keeling Curve on my left forearm.
The broader context was questions of what would happen if carbon dioxide levels went up dramatically (the Keeling Curve was relatively flat back then, but simple extrapolation suggested trouble) was mostly of scientific interest at the time.
The specific context was the carbon dioxide issue had received a boost in 1965 with Lyndon Johnson’s message to Congress about pollution, and a report at the end of the year by the President’s Science Advisory Committee (see November 7th).
What I think we can learn from this – the scientists were looking into it…
What happened next – it got published, obvs. And their 1975 paper was an even bigger deal…
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
Thirty one years ago, on this day, October 26th, 1994,
Scientists, politicians and economists recently gathered in New Zealand for the Greenhouse 94 conference from October 10 to 14. Discussions at the conference confirmed that the heat is on: sea levels are rising, climate patterns are shifting, and the atmosphere is heating up. ZANNY BEGG reports on the implications of global warming.
Ben Elton, in his best-selling novel Stark, was able to describe the earth as a stinking trash can of multinational companies — with an ozone layer in tatters, sea temperatures rising and pollution transforming the air into a toxic soup — and keep it funny. But when straight-faced scientists begin to talk about the threat global warming poses to the planet there isn’t much to laugh about.
Two thousand five hundred scientists working for the Intergovernmental Panel on Climate Change (IPCC) issued a statement on September 14 that told the world what we didn’t want to know: carbon dioxide levels are on the rise and the world’s climate is at a serious risk from human activity. This was confirmed by discussions at the Greenhouse 94 conference, convened by CSIRO, which concluded that sea levels and temperatures in the Oceania region have been rising steadily since the beginning of the century.
Elwin Jackson attended the Greenhouse 94 conference for Greenpeace. His prediction for the future, if no reduction of greenhouse gases occurs, is as stark as Ben Elton’s. “In the year 2040”, he explained to Green Left Weekly, “we could see famine stalking through South-East Asia. We could see more droughts, increased flooding, rapidly changing weather conditions and more pests. The conditions we see in many parts of Africa could come to this part of the world. The human cost of this would be horrific.
Anon, 1994. Greenhouse alert: global warming is a global warning. Green Left Weekly October 26, 1994
The amount of carbon dioxide in the air was 359ppm. As of 2025, when this post was published, it is 425ppm. This matters because the more carbon dioxide in the air, the more heat gets trapped. The more heat, the more extreme weather events. You can make it more complicated than that if you want, but really, it’s not. Fwiw, I have a tattoo of the Keeling Curve on my left forearm.
The broader context was that the first “Greenhouse” conference, in 1987, had been crucial – an opportunity for scientists working in different domains to compare notes. For a few years the scientists were being sorta listened to (which is distinct from saying they had a lot of influence).
The specific context was by 1994 climate had disappeared from the front pages and into the boring bits where policies are combatted and not really explained. Yawnsville. Still, the grinding work of science goes on…
What I think we can learn from this – issue attention cycles are a thing. More people should know about them
What happened next – scientists kept sciencing. Emissions kept climbing.
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
If you and I lived in a rational world, a world that cared about the future of human life – and indeed all life – on the planet, then by now October 15 would be internationally recognised as “The Day We Woke Up.”
We don’t, it isn’t, and the carbon dioxide concentration continues its relentless climb because we are pouring 40 billion tonnes into the atmosphere every year.
October 15 has two claims to be Wake Up day. The first and perhaps weaker one is that 54 years ago, in 1971, a report with the ominous title “Inadvertent Climate Modification” was published, in the run-up to the first big United Nations conference on the human environment, in June 1972.
The bigger claim, the one this article/blogpost/jeremiad covers, is the climax of a meeting of climate scientists gathered (not for the first time) in Villach, Austria in October 1985.
The statement they made is that day is painful. Here’s the beginning of it.
The Conference reached the following conclusions and recommendations:
1. Many important economic and social decisions are being made today on long-term projects major water resource management activities such as irrigation and hydro-power, drought relief, agricultural land use, structural designs and coastal engineering projects, and energy planning all based on the assumption that past climatic data, without modification, are a reliable guide to the future. This is no longer a good assumption since the increasing concentrations of greenhouse gases are expected to cause a significant warming of the global climate in the next century. It is a matter of urgency to refine estimates of future climate conditions to improve these decisions.
2. Climate change and sea level rises due to greenhouse gases are closely linked with other major environmental issues, such as acid deposition and threats to the Earth’s ozone shield, mostly due to changes in the composition of the atmosphere by man’s activities. Reduction of coal and oil use and energy conservation undertaken to reduce acid deposition will also reduce emissions of greenhouse gases, a reduction in the release of chloro-fluorocarbons (CFCs) will help protect the ozone layer and will also slow the rate of climate change.
3. While some warming of climate now appears inevitable due to past actions, the rate and degree of future warming could be profoundly affected by governmental policies on energy conservation, use of fossil fuels, and the emission of some greenhouse gases.
Villach gave scientists who attended the confidence (and a document) to go knocking on as many policymakers’ doors as they could. They did this, and less than three years later the climate problem finally became an “issue” that politicians could not actively ignore (1).
The climate issue
An awareness that something must be trapping some of the sun’s heat goes back to 1824, and the French scientist Fourier. By the mid-19th century, “carbonic acid” (carbon dioxide in solution) had been identified as one of those “greenhouse gases” by Eunice Foote (her work forgotten and only rediscovered in 2010) and John Tyndall. At the end of the 19th century a Swede, Svante Arrhenius, did the calculations and guesstimated (if you call a year of manual calculations, mostly to distract from a messy divorce guesstimating) that if you doubled the amount of carbon dioxide in the atmosphere (principally by burning oil, coal and gas, with a side order of cutting down trees) then you’d heat the planet by 1.5 to 3 degrees above pre-Industrial levels. Arrhenius welcomed this – it would take hundreds or thousands of years and would allow food growing much further north. Soon after other scientists disputed Arrhenius’s findings, (falsely) saying that carbon dioxide didn’t act quite the way Arrhenius was assuming. Arrhenius replied, but carbon dioxide theory was largely (but not entirely) neglected until a British steam engineer called Guy Callendar presented a paper in 1938 saying that a) the world was warming (this was not controversial) and b) carbon dioxide levels were detectably higher (this was more controversial) and c) the first was being caused by the second (this was basically dismissed). Callendar received little support or interest in the UK, but American and Swedish scientists were less skeptical. The pivotal moment came in May 1953 when Gilbert Plass, a Canadian physicist working at Johns Hopkins University presented work that confirmed Callendar. Plass said that
The large increase in industrial activity during the present century is discharging so much carbon dioxide into the atmosphere that the average temperature is rising at the rate of 1.5 degrees per century.
From there on, other scientists took up the mantle. Thanks to the International Geophysical Year (1957-8) super accurate measurements of atmospheric carbon dioxide began to be taken around the world, most importantly and famously at the Mauna Loa observatory in Hawaii and Antarctica (as far away from factories and forests as you can get).
Throughout the 1960s, awareness and concern grew generally about the impacts of human actions on the natural world (Rachel Carson’s Silent Spring being the most famous, but by no means the only example).
In the late 1960s pressures grew and various bodies (including NATO!) began to monitor environmental issues. The International Council of Scientific Unions set up the Scientific Committee of Problems of the Environment (SCOPE). The 1972 UN Conference on the Human Environment put “environmental matters” on the agenda, and a few agreements were signed. Another outcome was the United Nations Environment Program (UNEP). SCOPE and UNEP co-hosted the Villach meeting, along with the World Meteorological Organisation.
At the same time, Exxon and other oil companies were looking at the problem. As the website, full of documents released because of various lawsuits, says “Exxon Knew.”) (see also All Our Yesterdays posts)
The first World Climate Conference, held in Geneva in February 1979 could have been the moment when the issue broke through, but rearguard actions by skeptical scientists (including John Mason, head of the influential United Kingdom Meteorological office) prevented a stronger statement. In the US, then led by Jimmy Carter, Gus Speth and others were trying to push through greater awareness of the issue (see for example the Global 2000 report).
The politicians were not interested. New UK Prime Minister Margaret Thatcher was briefed by her chief scientific advisor on the climate issue and was incredulous, saying “You want me to worry about the weather?”
Ronald Reagan was not even aware of Global 2000 (and famously said that trees cause pollution). The people behind him were actively hostile to environmentalism (see Dunlap and McCright). Nonetheless, scientific work continued, and members of congress (including a young Al Gore) were listening. By 1982 was on the evening news in the United States
Why 1985?
By 1985 UNEP and WMO had co-hosted several meetings on climate, chaired by the redoubtable and enormously respected Swedish scientist Bert Bolin (from 1959 onwards Bolin had been trying to raise concern about C02 build-up.
There are competing explanations for why the Villach Conference had what influence it did. One is simply that, thanks to recent work on the basket of non-C02 gases as being, if combined, almost as important as C02 the science was now clear enough, and the warming fingerprint emerging, that the scientists felt able, and indeed compelled to act.
The other is that – thanks to the discovery of the Ozone hole, atmospheric scientists now had enough credibility and access to decision-makers to make a concerted push on carbon dioxide worth a shot.
The short term impacts in the English-speaking world were most felt in Australia, the US and Canada.
In Australia the Science Minister of the day, Barry Jones, had been able to establish (in the teeth of indifference, derision and opposition from his Labor colleagues) a “Commission for the Future.” It chose to launch “The Greenhouse Project”.
I haven’t dug into the details, but this was in all probability influenced by Villach. The Australian Environment Council (made up of state and federal environment ministers) had been aware of the greenhouse issue in 1981 (and individually much earlier). It had then literally disappeared from the agenda of the AEF’s meetings until June 1986, when the head of the Atmospheric Physics Division of the CSIRO gave a presentation, based on Villach (2). Various ministers (including South Australia’s Don Hopgood, began spreading the word.
By 1988, ozone and greenhouse (often conflated and confused) were being discussed very widely in Australian society.
A report on Villach appeared in Search, the magazine of the Australian and New Zealand Association for the Advancement of Science.
In the United States, senators (Republican and Democrat – this before the Republican went totally mad) held hearings – the famous one is with Carl Sagan.
The Washington Post, until recently a proper newspaper ran articles based on Villach and its aftermath such as “A Dire Forecast for ‘Greenhouse’ Earth” (June 1986).
The Canadians, long aware of the issue, hosted a crucial meeting on The Changing Atmosphere in June 1988, in the same venue that they were also hosting the G7 meeting.
In the UK the response to Villach was much more muted. Fred Pearce quotes a senior scientist, Tom Wigley, as saying Villach was a “waffly non-event” whose influence has been “grossly exaggerated.” This is backed up by an interview I did recently with a British scientist who was also at Villach, and the documentary record I’ve been able to uncover at The National Archives – Villach did not “light a fire” under the British, for reasons that intrigue only me.
From 1988 on there have been countless reports and warnings. The IPCC continues to produce assessment reports (six and rising) and special reports on this that and the other. All these reports may eventually serve a purpose as flood defences. If “we” had been able to absorb the import of what those scientists said at Villach, and act accordingly, it might have been different – or, perhaps the most we could have done is delay the impacts we are seeing now for a few years.
Villach, for me, represents the tragic dilemma of our species. We are smart enough to cause ourselves no end of problems. We are smart enough to see some of those problems before they hit. We are not, it seems, smart enough to do much about some of them.
The amount of carbon dioxide in the atmosphere was just under 350ppm. Now it’s at 425 and climbing more each year. There are large amounts of gnarly trouble ahead. Relatively small bits are already here. More is to come.
Pearce, F. 2005. The Week the Climate Change. New Scientist volume 188; issue 2521
Footnotes
Things have changed back.
That scientist, Brian Tucker, is a somewhat confounding figure. He had written a monograph on Carbon Dioxide and Climate in 1981. Upon retirement he decided the whole issue was overblown, possibly a hoax, and contributed a couple of appalling articles to a right-wing/libertarian junk-tank, and generally made a fool of himself.
The effect of overlapping of atmospheric H2O, CO2 and O3 absorption bands on the radiation budget perturbation caused by CO2 doubling is investigated. Since the effect depends on the amount of gases in the atmosphere as well as on the strength of the absorption bands, we examine the effect associated with the variation of gas abundance using a narrow band representation for the absorption bands. This band representation allows for the absorption band structure and thus accounts for the correlation of the spectral feature of the absorbing gases.
It is found that the presence of H2O and O3 has a relatively small influence on the CO2-induced perturbation of both solar and thermal radiation in the stratosphere. However, in troposphere and surface, the overlapping effect appears to be quite significant and changes the vertical distribution of the CO2-induced radiation energy perturbation. For example, in the infrared, the effect is to reduce the effectiveness for CO2 to emit and in the mean time increases the tropospheric absorption of downward thermal flux from the stratosphere due to CO2 increase; the net effect of the overlapping of gases is to increase the tropospheric warming and decrease the surface warming caused by CO2 increase. It is also found that the overlapping effect exhibits strong seasonal and latitudinal variations due primarily to variations in atmospheric H2O.
The amount of carbon dioxide in the air was 340ppm. As of 2025, when this post was published, it is 430ppm. This matters because the more carbon dioxide in the air, the more heat gets trapped. The more heat, the more extreme weather events. You can make it more complicated than that if you want, but really, it’s not. Fwiw, I have a tattoo of the Keeling Curve on my left forearm.
The broader context was that by the early 1980s there was a noticeable uptick in the number of scientific papers examining the likely consequences of a lot more carbon dioxide in the atmosphere. Because we were putting a lot more carbon dioxide into the atmosphere, and showed no signs of wanting to stop, or even thinking that stopping might be a good idea.
The specific context was – aftermath of the First World Climate Conference, the Global 2000 report etc…
What I think we can learn from this is that we knew plenty, almost 50 years ago.
What happened next – it would be 1988 before the issue “broke through.”
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
Forty-eight years ago, on this day, August 15th, 1977,
Theoretical climate effects of doubling the atmospheric carbon dioxide content.
Presented at the Third Ecology-Meteorology Workshop, University of Michigan Biological Station, 15-18 August 1977
The amount of carbon dioxide in the air was 333ppm. As of 2025, when this post was published, it is 430ppm. This matters because the more carbon dioxide in the air, the more heat gets trapped. The more heat, the more extreme weather events. You can make it more complicated than that if you want, but really, it’s not. Fwiw, I have a tattoo of the Keeling Curve on my left forearm.
The broader context was that by the mid-1970s scientists studying the issue were getting more and more concerned. In 1975 the first “global warming” paper appeared – vale Wally Broecker) and the National Academies of Science started paying attention to “Energy and Climate”. President Carter had kicked off the “Global 2000” report too. Word was getting round…
The specific context was that American science wasn’t at that time under full assault by a bunch of crooks, thugs and wilfully ignorant theocratic racists. So, the good old days.
What I think we can learn from this – People knew. Not everyone, but more than you’d think.
What happened next – in 1979 the First World Climate Conference happened in Geneva, Switzerland, organised by the World Meteorological Organisation. It could have been pivotal, but wasn’t. The thick end of another decade was wasted.
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
The late Mesozoic rock and life records implicate short-term (up to 105 to 106 years) global warming resulting from carbon dioxide—induced “greenhouse” conditions in the late Maestrichtian extinctions that terminated the Mesozoic Era. Oxygen isotope data from marine microfossils suggest late Mesozoic climatic cooling into middle Maestrichtian, and warming thereafter into the Cenozoic. Animals adapting to climatic cooling could not adapt to sudden warming. Small calcareous marine organisms would have suffered solution effects of carbon dioxide—enriched waters; animals dependent upon them for food would also have been affected. The widespread terrestrial tropical floras would likely not have reflected effects of a slight climatic warming. In late Mesozoic, the deep oceanic waters may have been triggered into releasing vast amounts of carbon dioxide into the atmosphere in a chain reaction of climatic warming and carbon dioxide expulsion. These conditions may be duplicated by human combustion of the fossil fuels and by forest clearing.
The amount of carbon dioxide in the air was 335ppm. As of 2025, when this post was published, it is 430ppm. This matters because the more carbon dioxide in the air, the more heat gets trapped. The more heat, the more extreme weather events. You can make it more complicated than that if you want, but really, it’s not. Fwiw, I have a tattoo of the Keeling Curve on my left forearm.
The broader context was that the 1970s was the decade when the basic science became “settled.” For what that turned out to be worth!
The specific context was that by this time the World Meteorological Organisation had said it would hold the First World Climate Conference, in Geneva, in February 1979.
What I think we can learn from this is that information on its own is not worth a bucket of warm spit.
What happened next. The scientists tried to interest the politicians. The politicians didn’t listen. In 1988 the politicians began to pretend to listen. Meanwhile, the emissions just went up and up.
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
The amount of carbon dioxide in the air was 337ppm. As of 2025, when this post was published, it is 430ppm. This matters because the more carbon dioxide in the air, the more heat gets trapped. The more heat, the more extreme weather events. You can make it more complicated than that if you want, but really, it’s not. Fwiw, I have a tattoo of the Keeling Curve on my left forearm.
The broader context was that through the 1970s scientists working on climatology, pollution, energy, food were starting to study carbon dioxide build-ups effects and saying in effect “er, we may have a serious problem on our hands”. This was true especially in (parts of) Europe and the US.
The specific context was that the Carter Administration was rather taken with shale oil as a way of securing “energy independence”. This raised the question of CO2 build-up to serious concern, and Jule Charney was asked to come up with a “definitive” answer to whether it was something to take seriously.
What I think we can learn from this – sometimes an issue will be “entrained” because of another one (in fact, that is surely the norm, but we struggle to understand it). In this case, an “environmental” issue gets a boost because of energy policy debates….
What happened next Charney et al basically said “there’s no reason to believe that a doubling in atmospheric concentrations of carbon dioxide – which are likely by 2050 or so – will do anything other than result in an increase of global average temperatures of somewhere between 1.5 and 3.5 degrees.”
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
Forty-eight years ago, on this day, June 6th, 1977 German climatologist Herman Flohn, who had been aware of Guy Callendar’s work during the war, asked “whither the atmosphere and Earth’s climate?,
Flohn at “Growth without Ecodisasters?” conference – Whither the Atmosphere and Earth’s Climates? by Prof. Hermann Flohn (Germany): Chman Dr Thomas F. Malone (USA)
The amount of carbon dioxide in the air was roughly 333ppm. As of 2025 it is 430ppm, but check here for daily measures.
The broader context was that in the mid-1970s it became obvious to smart scientists that the carbon dioxide problem was going to be THE issue – see for example Wally Broecker in Science in 1975.
The specific context was that by the mid-1970s there was also a steady circuit of these sorts of hand-wringing international conferences, the humanities version of what the IIASA crowd of technocrats were doing…
What I think we can learn from this is that the 1970s really was – as per Richard Nixon and the UK Conservation Society – the “decade of decision.” And we – at a species level – decided by not deciding. Oops.
What happened next
Flohn kept up the good fight – as late as the 1990s he was trying to push back against the climate denialists (LINK)
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
