That year, there were five invited speakers at a symposium at Columbia University. Teller talked about some wild applications for nuclear bombs, but he started his talk with these words about carbon dioxide:
"Carbon dioxide has a strange property. It transmits visible light but it absorbs the infrared radiation which is emitted from the earth. Its presence in the atmosphere causes a greenhouse effect in that it will allow the solar rays to enter, but it will to some extent impede the radiation from the earth into outer space. The result is that the earth will continue to heat up until a balance is re-established. Then the earth will be at a higher temperature and will radiate more. It has been calculated that a temperature rise corresponding to a l0 per cent increase in carbon dioxide will be sufficient to melt the icecap and submerge New York. All the coastal cities would be covered, and since a considerable percentage of the human race lives in coastal regions, I think that this chemical contamination is more serious than most people tend to believe."This comes from a book review of the symposium's talks on Amazon, and it's what The Guardian printed earlier this year. There was a question after the talk's end that offers more insight into Teller's thinking:
Dean Brown: Here is another clarifying question. Would you please summarize briefly the danger from increased carbon dioxide content in the atmosphere in this century?Teller wasn't pessimistic enough. In 1970 atmospheric CO2 was 16% above the preindustrial value, 21% in 1980, and by 1990 it was 27%.
Dr. Teller: At present the carbon dioxide in the atmosphere has risen by 2 per cent over normal. By 1970, it will be perhaps 4 per cent, by 1980, 8 per cent, by 1990, 16 percent, if we keep on with our exponential rise in the use of purely conventional fuels. By that time, there will be a serious additional impediment for the radiation leaving the earth. Our planet will get a little warmer. It is hard to say whether it will be 2 degrees Fahrenheit or only one or 5. But when the temperature does rise by a few degrees over the whole globe, there is a possibility that the icecaps will start melting and the level of the oceans will begin to rise. Well, I don't know whether they will cover the Empire. State Building or not, but anyone can calculate it by looking at the map and noting that the icecaps over Greenland and over Antarctica are perhaps five thousand feet thick.
This was almost six decades ago. Scientists knew. The oil industry knew. The Lyndon Johnson administration knew. A large research program should have been set up then, and something like the IPCC. Those denying a CO2 role should be ashamed of themselves.