Is Global Warming Causing the California Drought?
Most of the United States west of the 100th meridian is very dry. But back in the 19th century, when a period of unusually wet growing seasons was observed in the American West, many claimed it was proof that God was sending rain to help the white man settle the West, which had formerly been much more arid. God had withheld the rain from the "savages," but now that the Americans had arrived, "the Great American Desert" as it had often been called, was going to turn green. "Rain follows the plow" was another slightly less triumphalist theory, and settlers were told that growing crops out west would bring more rain.
Equally superstitious and unprovable is the assertion that the current drought in California is caused by man-made global warming. Anyone familiar with the west knows that huge swings in rainfall and climate can occur from one decade to the next. One such swing in conditions caused the Dakota Boom (and the resulting bust).
There is no doubt that the current lack of precipitation in California is unusual even in this context. Nevertheless, the region has been subject to more than one so-called “megadrought” in history. USA Today notes:
"As of now, probably very little of the California drought can be attributed to climate change with any certainty," said tree-ring scientist Edward Cook of Lamont-Doherty.
Overall, past droughts have probably been due to subtle changes in water temperatures in the tropical Pacific Ocean. Cooler water temperatures — known as La Niñas — tend to produce drier conditions in the West.
Another USAToday article notes: "Peer-reviewed studies are divided on whether the drought can be blamed on climate change."
But you certainly wouldn't know this from reading most news outlets. It's "settled science" to use an unintentionally ironic term used by some. Moreover, we might note that the issue of whether or not global warming is happening is completely independent of the question of whether or not the California drought is caused by global warming. But acknowledging this logical fact would get in the way of some good headlines.
As I've noted before, when we're talking economics and public policy, the presence of global warming is rather beside the point, since the climate scientists have never offered any actual proof that their preferred "solution" of mass impoverishment via carbon controls will do anything to solve their stated problem. And of course, since their plan is based on coercion, the burden of proof is very much on them. Moreover, climate scientists should stick to climate science, and not to political economy.