By the end of the century, many locations in the Northwest where snowpack levels are monitored will see rainfall more often than snowfall if the world continues on its current greenhouse gas emissions trajectory, according to a new scientific paper in the journal Geophysical Research Letters.
Sites at low- and mid-elevation levels, such as those in the Cascade Range, are the most vulnerable to near-term declines in snow days, according to the findings by researchers at Portland State University. Curbing emissions would help slow the rate of snow decline in the Northwest, the paper found.
The findings could have significant implications for hydropower supplies in the region as well as for the states that rely on that hydropower to keep emissions down. Hydropower produces as much as 80% of the Northwest's electricity each year, according to the Foundation for Water and Energy Education.
In the Northwest, snow accumulation, commonly referred to as snowpack, acts as a natural reservoir that accumulates throughout the winter in the mountains. When temperatures increase in the spring and summer, that snow melts and recharges groundwater and the rivers where many hydropower projects exist.
The paper also builds on several other recent scientific reports warning that more rainfall and lower temperatures increase the risk of rain-on-snow flash floods, which could impact hydropower facilities. Another recent paper indicated that most water infrastructure in the U.S. has not been designed to withstand increasingly extreme weather events tied to climate change.
