UW professor points to increased warming trends in Northwest
By Ann McCreary
No matter what steps are taken to head off the consequences of climate change, there is nothing that can be done now to avoid them entirely — it’s just a matter of “how fast and how much” the climate will change, according to a University of Washington climate researcher.
“The warming is already in the pipeline,” said Amy Snover, director of the UW Climate Impacts Group.
“We have set ourselves on the path to a future that does not look like the world we are living in,” Snover told a standing-room-only audience at The Merc Playhouse last week.
Last year was the warmest year on Earth since recordkeeping began in the 1880s, surpassing 2014, which was the second-hottest year. Of the 16 warmest years on record, 15 have taken place since 2001.
Snover brought the impacts of climate change home in a talk called “Climate Change in the Northwest: Implications for our Landscapes, Water and Communities.” Her Oct. 4 appearance was sponsored by the Methow Conservancy.
By the 2050s, average temperatures in the Northwest are predicted to increase by 4-6 degrees Celsius, and even more later in the century, Snover said.
“Our dominant impact pathway is through our snowpack,” Snover said. The mountain snowpack, which “predicts how much water we have for the summer dry period,” is expected to decrease in the Northwest by up to 30 percent in the 2020s, 44 percent in the 2040s, and 65 percent by the end of the century, she said.
In the Methow Valley specifically, however, the decrease in snowpack won’t be felt quite as soon, because the Methow River watershed is a somewhat colder ecosystem than other parts of the Northwest. The snowpack here is predicted to decrease by 44 percent by the 2080s, Snover said.
As the planet warms, precipitation will increasingly come in the form of rain, rather than snow. That means less snow stored in the mountains to feed rivers and streams during dry summer months, higher streamflows fed by rain in autumn and early winter, quicker snowmelt runoff, and lower summer streamflows, Snover said.
The Methow Valley watershed will likely not feel the impacts of these changes as soon as other areas, Snover said.
“This is not a super-sensitive basin … unlike the Yakima Basin, which changes almost entirely to a rain-dominated basin,” she said.
The transformation of precipitation to rain rather than snow means significant changes in the amount and timing of water availability, Snover said.
For production of hydropower, for example, it means an increased ability to make energy in winter and decreased ability to make energy in summer.
“But that is opposite of what demands will be. We’ll need less heat in winter and more cooling in summer” as the climate warms, she said.
It will mean more competition for scarce water in summer, and will limit the amount of water available to irrigators.
Salmon are also expected to suffer in this scenario as stream temperatures rise and become incapable of supporting the fish, “especially in the middle Columbia Basin,” Snover said.
Wildfire — no stranger to the Northwest now — will become more frequent and extreme, Snover said.
“The area burned by fire in the Columbia River basin is projected to double by the 2020s, triple by the 2040s, and increase five-fold by the 2080s,” relative to the median number of wildfires experienced between 1916-2006.
Forests will become increasingly vulnerable to the “combined risks of wildfire, drought and insects. These changes … have implications for all creatures that live in these ecosystems,” she said.
In attempting to cope with the changes to come, humans will need to “look at the complex interaction in these systems we depend on and figure out how to make them more adaptive and resilient in the future,” Snover said.
“I’m proud to claim the Northwest and Washington state … are at the forefront of the issue of climate change and what it means,” Snover said.
She pointed to the Okanogan-Wenatchee National Forest, which includes the Methow Ranger District, as an example of a government agency adopting a forward-thinking approach to climate change.
The Okanogan-Wenatchee National Forest was the first to include climate change as a consideration in its Forest Management Plan in the early 1990s, she said. And the Okanogan-Wenatchee Forest Restoration Plan bases restoration goals on ecosystem conditions that are anticipated in the future, rather than on current or past conditions.
“They’re thinking about the next hotter and drier ecosystem than the one they’re in,” she said.
“Climate change is redefining what is normal,” Snover said, and “will require innovative and nimble responses and longer-term transformation of our communities and expectations.”
Although the international community agreed to try to hold the rise in temperature to 2 degrees Celsius by the end of the century, Snover said the Paris Agreement adopted in 2015 is unlikely to meet that goal, even if all countries met their targets for reducing emissions and controlling greenhouse gases.
Society must prepare for the consequences by considering climate change in all aspects of life, such as land use planning, transportation, energy, public works, building and construction, parks and recreation, and social services.
Climate change will affect all natural and manmade systems, and escalate pressures on those systems that are already being felt, she said.
“To solve climate change there are no silver bullets, there are silver BBs,” Snover said. “We are already behind on what we need to do to align our economies and ecology … and climate change is just going to make it go faster.”