The National Academy of Sciences (NAS) has just issued yet another report on global warming. A substantial part of it is based upon the "U.S. National Assessment" (USNA) of global warming, yet another government report that came out right before the last election. In turn, it was based, in large part, on computer models used in yet another government report on global warming, from the United Nations' Intergovernmental Panel on Climate Change.
Together, the best I can tell, these were produced by a total of a couple thousand people. Together, they were dead wrong about the most fundamental aspect of climate change, namely how we are changing our atmosphere.
First, a little physics. It has been known since at least 1872 that carbon dioxide--a byproduct of combustion, or the meta-respiration of civilization, dependent upon your point of view--traps warming radiation. It has also long been known that its warming effect becomes less at increasingly high concentrations. As a result, a constant increase in atmospheric carbon dioxide results in less and less warming over time.
So, the only way to keep warming the atmosphere at a constant rate is to add carbon dioxide at an increasing, or exponential rate. This is what the U.N., the USNA, and the National Academy all assume ... at least inasmuch as the Academy report states its parentage is the USNA, in its section titled "Consequences of Increased Climate Change".
The fact is that carbon dioxide has not accumulated in the atmosphere at an exponential rate for the last quarter-century: This is obvious to anyone with an Internet connection (in order to download a graph of the carbon dioxide history), eyeballs and a ruler. You will see that the behavior of the last 25 years looks a lot more like a straight line than an upward-pointing curve. Those with statistical expertise could also enter the data into a program like Excel and see if drawing an up-curve through the data results in a significant improvement over a straight line. The answer, for the last 25 years, is no.
This can only mean one thing. The linear change in carbon dioxide for the last quarter-century will result in an inevitable and inexorable slowing of global warming in coming decades.
So why isn't carbon dioxide increasing exponentially, even as the number of people are? Two reasons: We are becoming increasingly efficient, and the planet is getting greener.
We now produce a (deflated) dollar's worth of stuff using about half as much energy as we used to. Neither the U.N. nor the EU, despite their blustering, forced us to do this. Instead, stockholders made it happen, demanding more output for less cost. There's every reason to expect this behavior to continue.
The earth got greener because more carbon dioxide made the plants grow better, and a warming, primarily of the winter, lengthened the growing season. Will this greening stop, as some fear, when forests become mature and fall over? Not if they're turned into houses, which last for hundreds of years. This is one very good argument for managed, as opposed to "natural" forestry.
How could the Academy, the National Assessment Team, and the United Nations fail to notice that they got the basic behavior of carbon dioxide (and therefore, future warming) wrong? Could thousands of scientists simply miss what anyone with a hard drive and a ruler can see? Of course not. But where would my profession be if we couldn't scare you into funding us any more?
In a world where he who presents the scariest argument gets the most funding, everything is threatening and nothing is benign.
It's not just in climate science, either. How about cancer? We spend just about as much money there as we do on global warming. The government regales us with impressively weak associations between diet, urban air, polar ozone depletion and death, when the lion's share of cancer deaths would go away if people would simply choose not to smoke ciggie butts. Which causes more cancer--increasing ultraviolet radiation by 2 percent from ozone depletion (itself maybe too large an estimate) or going to the beach and taking off 98 percent of your clothes? But simple behavior changes cashier armies of regulators, who, thank you, would much rather be employed. So we tout the obscure while ignoring the obvious.
Which, sadly, is why thousands of the best minds in America aren't eager to tell you that changes in atmospheric carbon dioxide have been so slow that global warming is likely to slow down in future decades. Exactly when, though, no one knows. Please pass the funding until I figure this out.