Forests and brush moving up mountainsides as the climate warms could take a big gulp from streams and rivers, potentially cutting runoff by as much as 25 percent by the end of the century. Warmer temperatures will accelerate plant growth, triggering more water absorption and evaporation, according to researchers with UC Irvine and UC Merced.
“Scientists have recognized for a while that something like this was possible, but no one had been able to quantify whether it could be a big effect,” said UCI professor of Earth system science Michael L. Goulden. “It’s clear that this could be a big effect of climate warming and that water managers need to recognize and plan for the possibility of increased water losses from forest evaporation.”
According to the researchers, runoff from mountain ranges is vulnerable to temperature hikes that lengthen growing seasons and result in more vegetation growth at high elevations, according to the study, to be published this week in the Proceedings of the National Academy of Sciences.