This past January, California Governor Jerry Brown declared a state of emergency: Water is in short supply. An almost non-existent winter has been followed by a fleeting spring, with summer temperatures arriving in California six weeks ahead of schedule – and very little rainfall has come between them.
California’s reservoirs are at extreme lows, cattle are being moved out of state and food prices are rising. The state’s population of 38 million is in the midst of a serious drought.
A new study led by the Assistant Professor of Climate at Utah State University, Simon Wang, has analyzed California’s drought against the backdrop of climate change, producing quantitative evidence that suggests a connection between the dry state and global warming.
The technical report describes the formation of a dipole, or high-pressure ridge, which emerged from the unusually cold waters of Southeast Asia. This ridge anchored over the Gulf of Alaska and, in effect, created a wall against the moisture that normally sweeps down over the North American west coast. This dipole is also a contributing factor to this past winter’s “Polar Vortex,” which caused extreme cold weather in the northeastern United States. While the high-pressure ridge was preventing air from passing down to California, a low-pressure ridge built up north of the Great Lakes, eventually pushing freezing air down over the Northeast.
This study is significant, Wang explains, because it establishes a direct correlation between climate change and a weather event. “The inference from this study is that the abnormal intensity of the winter ridge is traceable to human-induced warming,” the report states, “but, more importantly, its development is potentially predictable.”
Wang admits that this study will not solve California’s current drought but “the reduction of carbon levels will help reduce the intensity of such events” in the future, and help engineers, farmers and firefighters to plan for the years ahead. It may even convince some policy-makers in the process.