Rising Oregon temperatures turn annual snowfall to rainfall

James Trotter, News Contributor

As Corvallis heads into its winter season, Oregon State University researchers analyze the impacts of longer wildfire seasons and rising temperatures on local Oregon forests and wildlife, finding a potential for lasting negative impacts.

Meghan Dalton, a climate researcher with the Oregon Climate Change Research Institute, said that winters in Oregon have been warming at a rate of approximately 2.7 degrees Fahrenheit per century since 1896. 

“The winter of 2014-15 was the warmest winter of these recent years at 6.5 degrees Fahrenheit above the 20th century average,” Dalton said via email. “Temperature since the beginning of this water year (which started October 1, 2018), has been warmer than normal in western and northeast Oregon, generally where the mountains are.”

Dalton went on to say that, given these statistics and local context, it is too soon to tell how this winter will turn out. Temperatures in the Pacific Ocean have been favorable for the development of an El Niño in the coming 6 months, which has the potential to make warmer and drier weather in Oregon.

Karen Shell, associate professor of atmospheric science and climate science program head, said that rising temperatures negatively affect the amount of snow falling and resulting snowpack levels in the Pacific Northwest, although it is uncertain whether the total amount of precipitation is changing.

According to Shell, snowpacks normally produced by winter snowfall act as a source of water for forested areas as they melt in the Spring and Summer. However, due to an increase in rain and a decrease of snow, that supply of water to forests is limited.

“The melt occurs earlier, so forests are getting drier, which means they’re more susceptible to wildfires,” Shell said. “So actually the wildfire season is starting earlier than it used to because forests are getting drier.”

According to Dalton, snowpack has declined in Oregon by 37 percent on average between 1955 and 2015. The lack of snowpack paired with a drier spring caused the 2015 wildfire season to be the largest recorded in the Pacific Northwest, with 1.6 million acres burned across Oregon and Washington.

Overall reduced snowpack also leads to decreased fresh water in streams, with agriculture as well as local wildlife suffering, according to Shell.

Boone Kauffman, professor of senior research with the Department of Fisheries and Wildlife, said that the increases in greenhouse gases and increased droughts raises the question of how local biota, or natural communities, will respond.

“We do know that if we get longer drought periods, we’re going to see less base flow, warmer streams, and that’s going to have profound impacts on iconic species like salmon,” Kauffman said. “Coldwater species are going to disappear from many of the watersheds of the pacific northwest.”

The largest contributors to these climate changes are the burning of fossil fuels, followed by deforestation and loss of forest cover, according to Kauffman. Fossil fuel emissions account for 80 percent of greenhouse gas emissions, and deforestation the other 15-20 percent, said Kauffman. Significant sources of fossil fuel emissions in the Pacific Northwest range from transportation. Methane released by livestock is another significant source of greenhouse gases according to Kauffman.

Kauffman believes the most important thing that an individual can do to reverse the effects of climate change is vote for politicians supporting climate-friendly policies.

“Vote for politicians that will do something in terms of policy that will truly move our society and global society following the Paris climate accords that are aimed a limiting changes due to climate change. ” Kauffman said. “The United States was the only country that, sad to say embarrassingly, has dropped out. We need to leading the world in addressing climate change – USA needs to be a leader, Oregon could be a leader.”

In Kauffman’s opinion, if Oregon adopted meaningful carbon emission reduction policies, it could be one of the few states to achieve carbon-neutral status through improved forest and public land management policies. Kauffman thinks policies extending timber rotations on public lands and protecting old growth forests, which act as greenhouse gas sinks, would yield positive effects as well.

Additional policies, Kauffman said, relating to decreasing livestock grazing on public land could aid in balancing greenhouse gas emissions in the western USA.

“So much of our land use today exacerbates the impacts of climate change through over-grazing, abusive grazing practices,” Kauffman said. Grazing removes forest cover over rivers thus impairing water quality and increasing stream temperatures. “Removing livestock grazing from public lands would greatly improve carbon sequestration in the rangelands of the public lands as well as improve water quality and quantity in these critical time.”

Oregon State University’s climate change research is something that students and staff can all be proud of, Kauffman said.

“Oregon State has long been a leader in some tremendous climate change research,”  Kauffman said. “We’re preparing our students through courses like Global Change Biology to meet challenges of climate change in the future.”

Global Change Biology, a course taught by Kauffman, studies the impact of a changing climate on natural systems and highlights actions that can be taken to slow widespread climate change.

As individuals, there are changes people can make to their lifestyles to reduce their carbon footprints, such as using alternative transportation, biking places instead of driving, lowering meat intake and having fewer children, but these need to come with policy changes as local state and national levels, according to Kauffman.

If Oregonians collectively do not take action against climate change, things are going to get a lot worse than they are now, according to Kauffman.

“We really need to highlight the need for students today to do something, the time to do something is now, or it’s really going to really, really affect your careers and certainly your children’s careers,” Kauffman said. “Your generation and future generations are going to depend on natural resources, and the cards are stacked against you right now if we don’t become carbon neutral by about 2050 or so. With threats to sea level rising and acidification and increasing temperatures and storms, we’re going to see some pretty difficult scenarios emerge in the coming 50 years.”

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