From “All Our Yesterdays” – Jan 28, 1987 – a warning from history

I have a side project – a website on which I blog something that happened “that day” in “climate” (that’s a loose term) history. Today there’s two posts – here’s the second…

An extra “All Our Yesterdays” post today, in honour of two excellent scientists, Professor Veerabhadran Ramanathan and Professor Wally Broecker. It was Ramanathan’s work on non-carbon dioxide greenhouse gases which had stiffened the resolve of the Villach attendees, and Broecker had been similarly involved. On January 28, 1987 they testified to Congress. Here is a long quote from a chapter in an ancient but sadly prescient book, “The Challenge of Global Warming.”

The Senate took up the greenhouse effect and ozone depletion issues again in January 1987. In fact, it became the subject of the first major hearing by the Senate Environment and Public Works Committee in the new Congress. Two critical and relatively new problems were discussed at this hearing that were to become central aspects of the growing urgency associated with the global warming problem.

Ramanathan argued in the hearing that atmospheric greenhouse gas concentrations had already been altered sufficiently by 1980 to commit the earth to a 0.7 to 2 degrees Celsius warming. With each passing decade Ramanathan estimated that an additional 0.2 to 0.5 degrees Celsius was being added. His analysis meant that by the year 2020 – in 33 years – the earth would be committed to as much as 4 degrees Celsius warming. Many scientists believe that the earth has not been 4 degrees Celsius warmer for tens of millions of years. Ramantahan’s testimony established that society was already locked into a substantial amount of climate change no matter what governments did. The problem was no longer a question of whether a change would occur but how much and when.

The second major issue was raised by Wally Broecker, a geochemist at the Lamont Dougherty Laboratory.  Broecker’s testimony was a follow-up to a talk he had given at an EPA conference in June. Broecker said that an examination of the history of climate change suggested that the greenhouse effect might push the earth into a state of rapid change – reorganizing the earth systems in the process. Broecker had little faith that society would experience a linear and gradual change in global temperature and climate as suggested by general circulation models of the atmosphere. The key implication of Broecker’s testimony was that the buildup of greenhouse gases could force the climate system to go into a state of rapid change and that society ultimately had limited ability to predict what that change might bring.

Page 264 Pomerance, R. (1989) “Dangers from climate warming: A public awakening,” in Abrahamson, D. (1989) The Challenge of Global Warming. Washington, DC: Natural Resources Defense Council