A new report from the federal government outlines the ways climate change is likely to affect the Pacific Northwest over the next century.
The report is called the Fourth National Climate Assessment and was produced by the U.S. Global Change Research Program. In it, the report states climate change is likely to affect everything from salmon numbers, to agriculture harvests and the location of towns in Washington state. It also falls in line with what University of Washington researchers had previously said could happen in King County.
The report starts with background, including the fact that the Pacific Northwest has warmed nearly two degrees since 1900, which is at least partially attributed to human-caused emissions of greenhouse gases. This has led to a reduction in mountain snowpack, increased wildfire activity and has sped up the usually slow release of water for people, rivers and fish and agriculture uses.
The hot, dry year of 2015 is often used as a benchmark for what the climate will likely look like by mid-century in Washington state. It was marked by drought, water scarcity and large wildfires that hurt farmers, hydropower production, drinking water, salmon and recreation opportunities. If these conditions become more common as the Earth continues to warm, it could lead to heat and drought impacts to agriculture, spikes in heat waves and record cases of infectious diseases.
The report focused on major areas that could be affected, including the region’s natural resources economy. The Pacific Northwest, including Washington, Idaho and Oregon, is one of the nation’s top producers of 28 agricultural products. Agriculture, forest and fisheries industries accounted for more than 700,000 jobs and more than $139 billion in sales during 2015, with $58 billion of this coming from Washington state from 303,000 jobs. These industries as well as outdoor recreation are sensitive to climate vulnerability, the report said.
Reduced water availability coupled with heat stress impacts crop production and livestock health as well as commercial fisheries, especially during dry years when river temperatures increase. Many species of fish, including salmon, are sensitive to warm water and often stop moving until water temperatures cool down. It can also drive fish further beneath the surface of lakes to areas where oxygen levels are not high enough and kill them.
The report said under high carbon emissions projections, up to 22 percent of salmon habitats in Washington state could be destroyed by late century resulting in $3 billion in economic losses. Toxic algae blooms on the Pacific Ocean are expected to increase, potentially leading to widespread fishery closures and waters warming as far north as the Bering Sea. While this could devastate the fishing industry, it could also allow for new opportunities in the Pacific Northwest if management agencies can coordinate effectively. Long term, the region will need to maintain current fisheries and open new ones.
A warming climate will change agriculture in the region. Irrigation demands among farmers in the Columbia River Basin are projected to increase 5 percent in response to climate change by the 2030s. Higher temperatures have already led to earlier flowering for tree fruits, which can lead to a mismatch between pollinators’ availability for fruit setting and can affect fruit quality and yield, the report said. Water and heat stressed plants are easier prey for pests and diseases.
In many parts of the U.S. West, including Washington state, water rights are metered out based on when the water right was established, meaning any water right created after the early 1900s only has junior water rights. These water rights holders are the first to have their water supply curtailed during drought. The report suggested states look at ways to create a more robust water rights market, but there are many institutional barriers to this.
In drier areas of Washington and Oregon, farmers are beginning to look at dryland farming, which includes relying on residual winter soil moisture instead of irrigation. Farmers in Puget Sound have said they may change the crops they grow in the future, possibly moving away from head lettuce or cabbage to cucumbers, tomatoes and peppers.
On wildlife, the report said endangered and snow-dependent species will be hit the hardest by warming temperatures. Game species like elk and deer may be helped by it as milder winters and less snowpack leave more food available for them. This same reduction in snow packs will also worsen drought and the availability of water supplies for fish and humans. Boating and water-based recreation will likely suffer due to lower reservoir and river levels during the summer.
Warmer temperatures could increase diseases and disease-carrying insects for both humans and animals. Lyme disease is already spreading more rapidly in the Pacific Northwest due to warmer temperatures, and West Nile virus-carrying mosquitoes are appearing earlier in their season.
Global warming will harm human health in other ways, too, the report said. Even under low-warming scenarios, the particulate levels from wildfires in the region are expected to increase by 160 percent by mid-century. This will be particularly dangerous to residents with respiratory illnesses like asthma, the young and the old.
On top of fires during the hot summer months, less precipitation will freeze during the wet winter months, resulting in higher concentrations of rain and flood and landslide risks. Areas of Washington state, particularly in southwest Washington, flood frequently and many East King County communities along the Snoqualmie River are vulnerable to flooding.
At the same time, sea levels are expected to rise more than four feet by the end of the century. Several tribes in Washington state, including the Quinault Indian Nation, are beginning to look at ways to move their towns out of the path of rising seas. Urban areas in Seattle and Portland will also be affected by higher sea levels.
The report comes weeks after Washington voters struck down Initiative 1631, which would have created a carbon fee on large producers in an attempt to curb emissions in the state. President Donald Trump was voted into office partially on a platform which denied climate change, calling it a hoax despite clear evidence to the contrary.
In October, the United Nations issued a report saying the world had only 12 years to prevent global temperatures from climbing more than 1.5 degrees Celsius. If temperatures reach above this, it will dramatically increase the risks of drought, floods, extreme heat and poverty for hundreds of millions of people, The Guardian reported last month.
