There is much to be said about the Obama administration's linkage of California's extreme drought and global warming. For starters, President Obama and John Holdren, his chief science advisor, should spend a little time in the United States Global Change Research Program's library. There they will find the U.S. government's recently updated 2008 study on the issue, “Weather and Climate Extremes in a Changing Climate.”
The study notes that the 1930s and 1950s were drier than the current decade and concludes that “droughts have, for the most part, become shorter, less frequent, and cover a smaller portion of the U. S. over the last century … The trends averaged over all of North America since 1950 are similar to U.S. trends for the same period, indicating no overall trend.”
|Droughts have, for the most part, become shorter, less frequent, and cover a smaller portion of the U. S. over the last century.|
Obama and Holdren would also do well to check out the UN Intergovernmental Panel on Climate Change for 2012, which said this about the global drought situation: “There is not enough evidence at present to suggest high confidence in observed trends in dryness due to lack of direct observations, some geographical inconsistencies in the trends, and some dependencies of inferred trends on the index choice. There is medium confidence that since the 1950s some regions of the world have experienced more intense and longer droughts (e.g., southern Europe, west Africa) but also opposite trends exist in other regions (e.g., central North America, northwestern Australia).”
As for California, Obama and Holdren should read the Jan. 25 edition of the San Jose Mercury News, which reported the conclusions of scientists studying droughts in the Golden State: “Through studies of tree rings, sediment and other natural evidence, researchers have documented multiple droughts in California that lasted 10 or 20 years in a row during the past 1,000 years -- compared to the mere three-year duration of the current dry spell. The two most severe mega-droughts make the Dust Bowl of the 1930s look tame: a 240-year-long drought that started in 850 and, 50 years after the conclusion of that one, another that stretched at least 180 years.”
In other words, as Prof. Roger A. Pielke of the Center for Science and Technology Research at the University of Colorado puts it: “Some places have become dryer, others wetter, and not much confidence in asserting the presence of any trends at the global scale.” Since the science doesn’t support assertions by Obama and Holdren that the California drought is a product of global warming, and since surely neither of these worthies would ever intentionally deceive the American people, the only reasonable explanation that remains is that those assertions are political, pure and simple.
Political, that is, as in being intended to satisfy Obama's dedicated supporters in the Big Green environmental movement who worry that their man may be about to approve the Keystone XL pipeline. They probably shouldn't worry, though, because the president doesn't appear inclined to do anything that would offend his political base, and especially not Big Green.