Fifty eight ago, on this day, April 12th, 1968,
12 April 1968. Brief mention of C02 build-up Hibbard, W. R. (1968). Mineral Resources: Challenge or Threat?: Can technology meet our future needs for minerals and still preserve a livable environment? Science, 160(3824), 143–149.
doi:10.1126/science.160.3824.143
The amount of carbon dioxide in the air was roughly 323ppm. As of 2026 it is 428ppm, but check here for daily measures.
The broader context was that by 1968 intelligent people involved in air pollution, atmospherics etc were well aware of carbon dioxide build up. It had been mentioned by Lyndon Johnson in the beginning of 1965 and in November 1965, the President’s Science Advisory Committee, PSAC had released a report Restoring the Quality of Our Environment, which had an entire chapter on CO2 build up. By 1967 in articles about air pollution in Time and Newsweek and so forth would have a paragraph on the topic.
What I think we can learn from this is that by the late 60s, the dangers were understood. It was not clear if they would the potential dangers were understood. It was not clear that they would definitely emerge, if there were competing theories, but knowledge was there.
What happened next: We kept ignoring the problem. In 1988 it “broke through” and became an issue. But we mostly continued to ignore it.
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:
April 12, 1992 – seminar asks “How sustainable is Australian Energy?” (proposes switch to gas)
April 12, 1993 – “environmental economics” gets a puff piece