The U.S. is not in the driver's seat when it comes to charting the future course of global climate change that may result from carbon dioxide emitted by human activities. That seat is occupied by the world's developing countries, with large populations seeking to improve their standard of living through better access to energy. The world's developed countries, like the U.S., have been relegated to the backseat. And like most backseat drivers, they may think that they exert some influence, but mostly they are powerless and annoying.
The U.S. can spin its imaginary steering wheel and stomp on its imaginary brake all it wants, but those actions won't change the direction or the speed of approach of the climate changes that are to come.
Case in point: The mid-range estimate from the latest United Nations' climate assessment report is that the earth's average temperature will rise by about 2.2 degrees Celsius between now and the end of this century. The same computerized climate models used to make those projections indicate that the U.S.'s contribution to that rise is about 0.14 C. But even this minor amount may be an overestimate.
A collection of scientific evidence has been published recently that suggests that these computer models predict too much warming from greenhouse gas emissions. Over the past 25 years, for example, the earth only warmed up about half as much as was predicted to have occurred by the climate models. So the 0.14 C is probably closer to 0.10 C.
That value — one tenth of a degree — is the most climate change that the Obama administration and the Environmental Protection Agency would be able to mitigate even if they were able to eliminate 100 percent of carbon dioxide emissions from existing coal-fired power plants and from everything else as well, including cars, trucks, lawnmowers, backyard propane grills, home furnaces, natural gas electrical plants and on and on. No matter how successful they are in reducing emissions, the impact on the weather and the climate from global to local scales, will be scientifically undetectable and environmentally meaningless.
The only way that the EPA's emissions limits will have any climatic impact at all will be if they engender new, carbon-free energy producing technologies that are reliable, safe and widely adopted. There is no guarantee that these particular regulations will lead to those outcomes. Nor is it clear that government involvement is the best way forward.
But in the meantime, Americans will have their energy choice limited, their pocketbooks lightened, the reliability of their energy supply threatened and more government intervention in their lives.
Undoubtedly, the climate road ahead will be a bumpy one, marred by strong hurricanes, major floods, prolonged heat waves and rising seas. The degree to which such occurrences will be marked by our own hand may never be known. Nature is pretty good at roughening the road on its own. But one thing that we can be sure of is that any attempt by the EPA to mitigate these effects through carbon dioxide emissions restrictions will be negligible at best — at least to the climate.