The study, published Thursday in Geophysical Research Letters, found that climate change can be blamed for between 8 to 27 percent of the drought conditions between 2012 and 2014 and between 5 to 18 percent in 2014. Though these relative contributions of climate change differ between the two periods of time, due to differences in severity of the drought from year to year, the study said climate change’s absolute contribution was “virtually identical” between the two periods — meaning climate change has contributed a fairly steady amount to California’s drought over the last three years.
The study does make it a little easier to illustrate how climate change and natural variability interact in a drought situation, however. Natural weather variability means temperatures, precipitation levels, and humidity are constantly changing — but they’re changing while the undercurrent of climate change steadily brings temperatures up. Climate change, Williams said, “is like a bully that demands part of your money every year, and every year it demands more of your money than the year before. Every year, the bully — or atmosphere — is demanding more resources — or water — than ever before.”
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