Seventy three years ago, on this day, May 6th, 1953,
The Hobart Mercury runs a story on the presentation by Canadian physicist Gilbert Plass at the American Geophysical Union meeting in Washington DC.
The amount of carbon dioxide in the air was roughly 313ppm. As of 2026 it is 430ppm, but check here for daily measures.
The broader context was that in the 19th century scientists had figured out that something must be trapping a certain amount of the Sun’s heat from bouncing back into space. Eunice Foote and John Tyndall had figured out it was carbon dioxide (aka carbonic acid). At the end of the 19th century Svante Arrhenius had said that – over thousands of years – man’s release of carbon dioxide from burning fossil fuels would heat the planet. In 1938 British steam engineer Guy Callendar said it probably wouldn’t take that long.
The specific context was that World War Two had boosted the ability of humans to collect data and to analyse it. Plass had access to data and computers. And had ‘institutional heft’, being at Johns Hopkins University.
What I think we can learn from this is that the idea we might toast ourselves was well-reported a very long time ago.
What happened next. Sixteen years later a Tasmanian chemistry professor warned the Senate Committee looking at Air Pollution about carbon dioxide.
The 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.
Also on this day:
May 6, 1969 – a legacy lunch in Melbourne… – All Our Yesterdays
May 6, 1997 – The so-called “Cooler Heads” coalition created
May 6, 2004 – Australian Prime Minister John Howard meets business, to kill renewables