According to the AP article, just five years ago, Charles Monnett was of the scientists who helped galvanize the global warming movement by his observation that several polar bears had drowned in the Arctic Ocean. Now he has been placed on administrative leave and is facing accusations of scientific misconduct.
In this connection, an interesting (and bound-to-be-controversial) article is the one in the most recent issue of First Things written by the Cyrus Fogg Brackett Professor of Physics at Princeton University, Dr. William Happer, entitled "The Truth About Greenhouse Gases" (First Things, June/July, 2011), pp. 33-38. Just a few "sound bites":
I am a strong supporter of a clean environment. We need to be vigilant to keep our land, air, and waters free of real pollution, particulates, heavy metals, and pathogens, but carbon dioxide (CO2 ) is not one of these pollutants. Carbon is the stuff of life. Our bodies are made of carbon. A normal human exhales around 1 kg of CO2 (the simplest chemically stable molecule of carbon in the earth’s atmosphere) per day. Before the industrial period, the concentration of CO2 in the atmosphere was 270 ppm. At the present time, the concentration is about 390 ppm, 0.039 percent of all atmospheric molecules and less than 1 percent of that in our breath. About fifty million years ago, a brief moment in the long history of life on earth, geological evidence indicates, CO2 levels were several thousand ppm, much higher than now. And life flourished abundantly.
... Both the United States Navy (for submariners) and NASA (for astronauts) have performed extensive studies of human tolerance to CO2. As a result of these studies, the Navy recommends an upper limit of about 8000 ppm for cruises of ninety days, and NASA recommends an upper limit of 5000 ppm for missions of one thousand days, both assuming a total pressure of one atmosphere. Higher levels are acceptable for missions of only a few days.
We conclude that atmospheric CO2 levels should be above 150 ppm to avoid harming green plants and below about 5000 ppm to avoid harming people. That is a very wide range, and our atmosphere is much closer to the lower end than to the upper end. The current rate of burning fossil fuels adds about 2 ppm per year to the atmosphere, so that getting from the current level to 1000 ppm would take about 300 years—and 1000 ppm is still less than what most plants would prefer, and much less than either the NASA or the Navy limit for human beings.
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