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UC Davis students hike in the Grand Canyon, a landscape that has changed dramatically over the past thousands and millions of years. Photo Credit: Joe Proudman/UC Davis |
People often say things like Phoenix has always been dry; Seattle has always been wet; and San Francisco has always been foggy. But “always” is a strong word.
A study from the University of California, Davis, synthesizes climate trends across the Western U.S. during a relatively young period of Earth’s history — the Holocene Era, which stretches from the present day to the past 11,000 years. This look at the really Old West shows that the hallmarks of California’s climate — the foggy coastlines that gave rise to towering redwoods, the ocean upwelling that spawned productive fisheries, the warm summers and mild winters — began around 4,000 years ago.
It also reveals a time when the Pacific Northwest was warm and dry and the Southwest was warm and wet.