Fifty one years ago, on this day, December 3rd, 1974,
The CO2 question (that is, long-term temperature and precipitation changes caused by rising carbon dioxide levels) was absent from the Dynamical Climatology Branch and rarely touched on by Mason. This changed with the airing of Nigel Calder’s BBC television programme, The Weather Machine, in 1974. Calder, a well-known British science writer and former New Scientist journalist, painted the imminent coming of a new Ice Age in such dramatic terms that the House of Commons ordered the Meteorological Office to report on Calder’s pronouncements
‘Meteorological Office: Ice Age Predictions, House of Commons Debate,’’ 3 Dec 1974, Hansard, Vol. 882, cc. 440-2W
via Martin-Nielsen,
The amount of carbon dioxide in the air was 330ppm. 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 all sorts of predictions – about getting hotter and getting colder, for various reasons, were being thrown about in the 1960s and 1970s. Carbon dioxide build-up was acknowledged by all, but some (including Nigel Calder) were not interested.
One does wonder what Nigel’s dad, Lord Ritchie-Calder, thought…
The specific context was – 1974 was busy year, politically, and there was still ambiguity about what the future would hold for the climate (it wasn’t really for another 10 years that all doubt could be removed, though certainly by the second half of the 1970s more and more people were saying “it’s gonna get hotter, and carbon dioxide is the reason why”).
What I think we can learn from this – the BBC used to have the power to upset the applecart.
What happened next – a fierce prolonged two year spat between the BBC and John Mason, who was, by all accounts, an, ah “forceful personality.”
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:
December 3, 1968 – UN General Assembly says yes to a conference about environment. CO2 mentioned.
December 3, 1970 – Olof Palme looks to the future…
December 3, 1972 – #climate scientists write “gizza grant” letter to President Nixon