Paul Solman: Are headlines trumpeting the fact that carbon dioxide levels in the earth's atmosphere have now passed 400 parts per million for the first time in something like three million years unduly alarmist? Or are they a timely warning?
I asked noted environmental economist Martin Weitzman to address the question. ...
... Weitzman has also been working on environmental economics and most recently, in a series of widely cited academic papers, on the economics of global warming; the most famous, on the "Economics of Catastrophic Climate Change." ...
Martin Weitzman: Recently the concentration of atmospheric carbon dioxide (CO2) reached an unprecedented level of 400 parts per million. What is the significance of this "milestone"? Does it portend catastrophic climate change? The short answer is no. The long answer is a more complicated and more nuanced maybe. ...
The whole piece is only 2474 words and well worth a read, especially if you don't understand Weitzman when he writes for the journals (i.e., there are no equations as in, e.g., REStat, 2009):
