Fifty four years ago, on this day, March 4th, 1970, a scientist talks about a human-induced Ice Age. Not likely, he finds.
I find that the present particulate loading would have to be increased by a factor of 5 to produce a 3°C drop in mean planetary surface temperature. This work was done in November and December of 1969 and was presented before the International Solar Energy Society in Melbourne, Australia, on 4 March 1970.
Earl W Barrett,, 1971 letter in Science
The amount of carbon dioxide in the air was roughly 324ppm. As of 2024 it is 425ppm, but check here for daily measures.
The context was that scientists, especially in America, were beginning to look seriously at carbon dioxide buildup at national conferences, starting to get findings. And scientists fancied an international jolly – sorry, “opportunity to network and further the advance of the human species’ knowledge.”
Australia was still in the dark ages on carbon dioxide buildup, it would be 1971-72 before scientists (Pearman, Pittock) started being paid to look at this stuff. Meanwhile, Melbourne was in the grip of its pollution fever. So Barrett’s comments will have free received interest in the media.
Also, in September 1969, the C02 issue had already been discussed by Australian scientists – in public fora.
What I think we can learn from this
“International networks of concerned scientists” etc. Science is international blah blah. But from the late 1960s, carbon dioxide was being looked at.
What happened next
In 1972 a clean air conference in Melbourne that had a specific set of papers about CO2 buildup. We ignored the scientists until 1988. Then we heard them but have basically ignored them since then.
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:
March 4, 1998 – The Australian Greenhouse Office gets a boss…
March 4, 2003 – “Luntz memo” exposes Bush climate strategy
March 4, 2023 –Letter in FT: Global carbon price call is a classic delaying tactic
March 4, 2003 – Republicans urged to question the scientific consensus…