Expert: Global warming could hurt salmon

BOISE – During the next 50 years, global temperatures could rise 7 degrees resulting in a permanent reduction of Idaho’s average snowpack by more than a third, an expert told Idaho lawmakers this week.

Some of the changes, predicted by models accepted by a consensus of scientists, are already apparent, said Philip Mote, a University of Washington climate scientist.

“Most of the West has seen an increase in March flows just as the models predict,” Mote told the Idaho Legislature’s 36-member Expanded Resources Interim Committee on Thursday. The committee is looking at water issues statewide.

Mote said the current drought can’t be tied by the data to global warming. But the trends show the human-caused warming has changed nature since 1960.

Mote also said the average temperature increase would affect salmon, which rely on snowpack to provide water for their journey to the ocean.

In some streams, flooding will increase, scouring eggs from their stream beds at a critical time, Mote said. In other places, warmer water and lower stream levels will hurt fish in the summer. “There will be some stocks of salmon that will have a difficult time with global warming,” Mote said.

Other predictions include a reduction in the amount of snow in lower elevations, which could make it harder to store water in reservoirs and reduce the natural recharge of the expansive Snake River Plain Aquifer that provides water for much of southern Idaho.

Ron Abramovich, a water supply specialist with the federal Natural Resources Conservation Service, said that even if the same amount of precipitation fell as rain instead of snow, it would move through the watersheds early in the year and before the reservoirs are ready to begin capturing water.

“You’d have to more closely watch the management of reservoirs,” said Abramovich in a separate interview with the Associated Press.

Mote said allowing more flexibility in spring river management could aid Idaho and other Northwest states in addressing the changing snowfall and rain patterns.

“We’d have less concern for flood control and more concern on keeping reservoirs full in the summer,” he said.

Mote’s remarks were given to lawmakers, water experts and lawyers who are skeptical about human-caused global warming.

But the consensus of scientists, Mote said, is that humans are changing the global climate by dramatically increasing the concentration of greenhouse gases into the atmosphere.

“I’ve never really bought on big to the whole global warming theory,” said Sen. Dean Cameron, R-Rupert. “But I was impressed by the way he laid out the evidence.”