WASHINGTON, D.C. – President Barack Obama on Tuesday released the third U.S. National Climate Assessment, the most comprehensive report to date on how climate change is affecting the United States.
The report concludes that the Northwest United States may experience warmer temperatures; increased occurrences of troubling phenomena such as major wildfires, ocean acidification and coastal erosion; and potentially dramatic changes to its agriculture and ecosystems.
Oregon State University’s Philip Mote, director of the Oregon Climate Change Research Institute, co-authored the report’s Northwest chapter and served on the advisory committee for the overall report.
One important potential impact is dwindling mountain snow, according to Mote. “Climate models continue to project snow will melt earlier in the season.”
Climate scenarios for the Northwest disagree on exactly how precipitation will change in the future. However, most scientists agree that as the Northwest warms, the region will see more rain and less snow.
“This decrease in snowpack is potentially troubling for many communities that rely on snowpack for agriculture and municipal water,” Mote said.
Mote, who was in Washington D.C. for the release of the report, said the region’s snow loss is due to increasing temperatures, which could rise in the northwest by anywhere from 3.3 to 9.7 degrees Fahrenheit by 2100, according to the report.
“Changes in climate include a drying trend in the summer months, which will complicate the agriculture sector,” said University of Idaho agriculture researcher Sanford Eigenbrode, coauthor on the Northwest chapter.
Eigenbrode said Northwest farmers could see their crops threatened due to drought and extreme heat.
Major changes to the Northwest’s forests are expected by the 2040s, according to the report.
“A lot of the new research we present has to do with projected changes in ecosystems due to disturbances from fire, insect mortality in forests and how vegetation might change due to climate,” said Jeremy Littell, a research ecologist at the Department of Interior’s Alaska Climate Science Center and another chapter co-author.
Littell said many of the changes that are expected for Northwest forests could happen quickly.
“We often think of vegetation change as slow, but one point we make in the chapter is, given the rate of disturbance in the Northwest, we think the systems will change faster than we otherwise would expect,” Littell said.
Other potential changes covered by the report include what is referred to as ocean acidification.
Ocean acidification is the popular name for the process by which atmospheric carbon dioxide dissolves in the ocean making the world’s seawater less basic and hence more difficult for animals such as oysters to construct their calcium carbonate shells.
Ocean acidification is expected to increase along the Northwest’s coasts, according to the report.
“The coast is one of those areas where risk is going to be focused,” said Amy Snover, director of the Climate Impacts Group at the University of Washington and another co-author.
Global sea levels have risen by eight inches since that late 1800s. Worldwide, sea levels are projected to rise by another 1-4 feet by the end of the century.
In the Northwest, sea levels are rising slightly slower than the world average due to the region’s unique tectonic geology, which has been slowly raising the Northwest coastline. However, this will not last forever, Snover said.
“The point is sea level rise will be different in different places, but under pretty much all scenarios the rising sea will exceed what’s been seen before and it will do so at an accelerating rate,” Snover said.
Rising sea levels are expected to increase erosion of the region’s beaches and affect coastal ecosystems and communities.
Snover said the report’s Northwest chapter represents just a quick snapshot of the climate research and data that is now available.
“The good news is we know a lot about what to expect from climate change – this report and the attention that is coming to it is an opportunity to highlight that,” Snover said.
In December, Mote, Snover and OCCRI’s Meghan Dalton, published a 270-page assessment report covering the northwest. The report, Climate Change in the Northwest, further details the findings in the Northwest chapter.
The report’s national findings conclude climate change is caused primarily by human activity. The report states the impacts of climate change are already widespread across the United States. These impacts – which include effects to infrastructure, agriculture and human health – will persist as extreme storms, droughts and high temperatures are projected to continue into the future, according to the report.
The report notes adaptation to climate change is becoming more prevalent across the country.
Climate Change in the Northwest is available through Island Press or can be downloaded from occri.net. The third U.S. National Climate Assessment can be found on the White House website and on nca2014.globalchange.gov