Region feeling the heat, says expert
Drought or no drought, climate change has arrived in the Pacific Northwest.
That means higher average annual temperatures, reduced snowpack, earlier spring thaws and less river water in summer, said state climatologist Phil Mote.
“The warming seems to be unprecedented in the last 1,000 years,” Mote told a group of about 320 scientists in Tacoma on Tuesday.
The University of Washington research scientist, who belongs to the school’s Climate Impacts Group, was keynote speaker at the annual Washington Hydrogeology Symposium, held at the Sheraton Tacoma Convention Center. His topic: “Pacific Northwest Climate: Past, Present & Future.”
Mote apologized for what he said was a grandiose title, then went on to describe how atmospheric carbon dioxide was associated with temperature change even during the Ice Age.
Mote and other scientists blame excess carbon dioxide, a byproduct of fuel combustion, for temperature increases that first became apparent in the waning decades of the 20th century.
As for the region’s current snow deficit – and related drought status – Mote said scientists are investigating whether recent weather patterns reflect the influence of human-caused climate change. He insisted it’s too soon to know.
Even so, Mote, who has compared decades of Pacific Northwest snow records, said the region’s increasingly high average annual temperatures have already reduced average annual snowpack accumulations, particularly near the snow line.
“So should you buy a ski chalet at Snoqualmie Pass, or is that a bad investment?’’ Mote asked, then used a collection of graphs and charts to explain what’s going on.
Throughout the Pacific Northwest, average annual temperatures are likely to rise nearly 3 degrees between 2020 and 2030 and more than 4 degrees between 2040 and 2050, the Climate Impacts Group predicts. Those increases are compared to temperatures recorded between 1990 and 2000.
“Temperature alone is enough to drive changes in snowpack,” Mote said. So given what’s expected to happen during the next 15 to 20 years, buying that Snoqualmie Pass real estate probably “depends on whether you like hiking.”
Using computer models, the Climate Impacts Group has predicted that higher annual temperatures will most likely lead to more winter rain and less winter snow. Mote predicted a 59 percent reduction in Oregon and Washington snowpack by 2050, using 20th-century snowpack averages as his benchmark.
The Climate Impacts Group also has predicted an increased risk of winter floods as more precipitation arrives in the form of rain. Oregon’s Willamette River is particularly vulnerable, Mote said.
In Washington, the timing of the peak spring runoff now occurs about two weeks earlier than 20th-century records indicate.
Scientists aren’t sure what will happen as the volume of so-called greenhouse gases – including carbon dioxide – trapped in the atmosphere increases, Mote said. “We are pushing our climate to a state where we have no experience to judge,” he said.
He compared the situation to driving a car at 120 mph when it’s designed to go only 70: Accidents could happen.
Climate-related changes in the region’s water cycle are likely to affect everyone who depends on mountain snowfall, not just skiers, he said.
Mountain snowpack provides a reservoir for hydropower, irrigation, municipal water systems and fish.
Heavy spring rains and conservation might avert a shortage in Western Washington this year. But Mote said the forecast remains grim for the Yakima Valley, where irrigation water is already in short supply.
This story courtesy of the Tacoma News Tribune:
Region feeling the heat, says expert