KPBS: The Sierra Nevadas deliver freshwater runoff that could dry up if temperatures continue rising.
A new study suggests rising global temperatures could cut into California's water supply by altering high-altitude vegetation.
Water used to irrigate crops in the Central Valley often begins as runoff from the top of Sierra Nevada mountains. It's so cold up there, vegetation can't take root. But with global temperatures rising, that could change.
"Rain or snow comes in, and the vegetation -- the...