On this day 64 years ago…
In 1961, the U.S Public Health service hosted a symposium on “Air Over Cities.”171 Like many meetings of its type, its primary focus was urban air pollution, widely recognized as a threat to public health. Carbon dioxide frequently appeared in these discussions. Helmut Landsberg, Director of the Office of Climatology for the US Weather Bureau, included it in a table labelled “Concentration of Some Air Pollutants in the Atmosphere of urban areas.” Carbon dioxide was the first pollutant listed, followed by carbon monoxide, oxides of nitrogen, sulfur dioxide, aldehydes, chlorides, and 167 Id. at 108. 168 Id. at 177. 169 Id. at 303. 170 Id. at 320. 171 US PUBLIC HEALTH SERVICE, SEC TECH. REP. A62-5, SYMPOSIUM: AIR OVER CITIES (1961) [hereinafter 1961 PHS SYMPOSIUM]. 55 others.172
James Lodge of NCAR also highlighted CO2, noting that it was “generally agreed that the concentration of this compound in the earth’s atmosphere has increased since the turn of the century….”173 Lodge agreed that more research was needed, particularly to improve measurement techniques.174 Wendell Hewson also attended this meeting and argued for more research to better understand “the possible influence on our climate of increased CO2 in the atmosphere resulting from our combustion of fossil fuels.”175
Oreskes et al 2025 page 54-5
Climate-Change-and-the-Clean-Air-Act-of-1970.pdf
NOVEMBER 6-7 1961
Document Display | NEPIS | US EPA
The amount of carbon dioxide in the air was 317ppm. 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 industrialisation brings smogs (a word only coined in about 1906). This was known from the early 19th century (and the burning of coal as an air pollution problem goes back hundreds of years – Fumifugium, much?).
The specific context was the first air pollution conference had happened in 1958 – and Chauncy Leake had raised the carbon dioxide issue…
What I think we can learn from this is that carbon dioxide as a problem was understood fairly well by the early 1960s…
What happened next – in 1963 the Conservation Foundation held an important meeting. In 1965 the President’s Science Advisory Council released a report (see yesterday’s post!). And it still took another two decades to break through the inertia and resistance…
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.
Also on this day:
November 6, 1988 – Australian cartoonist nails response to #climate change
November 6, 1989 – Noordwijk conference – “alright, we will keep talking”
November 6, 1990 – Second World Climate Conference underway
November 6, 2001 – Howard plays the jobs-card vs Kyoto in Hunter Valley – All Our Yesterdays
November 6, 2009 – Kevin Rudd playing politics with the climate
The amount of carbon dioxide in the air was roughly 327ppm. As of 2025 it is 430ppm, but check