The settled science seems to be neither settled nor science.
We have already seen how the claims of President Obama and Governor Brown directly contradict those of:
- NOAA, which said the California drought wasn’t caused by global warming (“We are saying climate change would have not been a main driver of the precipitation anomalies, which was the fundamental cause of the drought,” said Seager.)
- Sheffield, who said that even though the atmosphere has warmed, droughts are no more frequent
- And Ljungqvist, who pointed out how warmth does not lead to greater wet/dry extremes
And yet, some scientists, as if to emphasize that the science isn’t settled, are nonetheless linking global warming with the West Coast drought. Lisa Sloan of U.C. Santa Cruz predicted in 2004 that melting Arctic sea ice would significantly decrease precipitation in the American West. Her theory is that global warming results in a rising column of relatively warm air that creates a high-pressure system that blocks the path of storms heading toward the West. Noah Diffenbaugh, a Stanford University climate scientist, concluded that greenhouse gases were likely a factor in California’s drought. His team found that the worst droughts in California's history occurred when conditions were both dry and warm, and asserted that global warming is increasing the probability those two weather patterns will coincide. He claims that this overlap of very dry and very warm years would not have happened without human influence. According to the Natural Resources Defense Council: “Parts of the Western U.S. are already experiencing water crises because of severe dry-spells, but with climate change, the entire country will likely face some level of drought.”