Across the West, from San Diego to Seattle, Portland to Denver, signs of our rapidly changing climate become clearer each year. Records show that temperatures are higher, snowpack is lower, forests are drier, and sea levels are encroaching on our coasts.
Photo: U.S. Department of Agriculture
As temperatures warm, the prevalence and duration of drought is expected to increase. California is currently in the midst of one of the state's worst droughts and climate models unanimously project increased drought in the American Southwest, including a growing risk of “mega-droughts” that last more than two decades.
Rising temperatures are leading to reduced mountain snowpack and earlier snowmelt in the West. These trends can exacerbate water scarcity by disrupting the timing and availability of water supplies. Reduced water availability forces greater tradeoffs between competing water use, including agriculture, ecosystems, and urban areas.
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Photo: Rejané Claasen/Flickr
Increasingly, dry conditions will increase the pressure on groundwater supplies as more is pumped to meet demand even as less precipitation falls to replenish it. Groundwater supplies are like a bank account – when inputs match outputs, groundwater levels remain stable. Groundwater levels decline when more groundwater is pumped out than is replenished. Groundwater levels have been declining for decades in many places in the Western U.S., such as California’s San Joaquin Valley and the Ogallala Aquifer in the High Plains region.
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Photo: WA DNR
As temperatures rise in the Western U.S., wildfires are increasing, wildfire season is getting longer, and costs are soaring. Higher spring and summer temperatures and earlier spring snow-melt result in forests that are hotter and drier for longer periods of time, priming conditions for wildfires to ignite and spread. The wildfire season has grown from five months, on average, in the 1970s to seven months today, and the annual number of large wildfires has increased by more than 75 percent over the same time period.
Photo: Benjamin Drummond/bdsjs.com
The Pacific Northwest has warmed at least 1.3°F since 1895 and the impacts of this warming on the sensitive ecosystems of the region are already apparent to many residents. Shellfish hatcheries are failing because of an acidifying ocean, record-breaking wildfires are destroying forests and communities, and declining snowpack and earlier snowmelt in the mountains are jeopardizing freshwater species like salmon and trout.
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Tens of millions of trees have died in the Rocky Mountains over the past 15 years, over an area as large as Colorado, victims of a climate-driven triple assault of tree-killing insects, wildfires, and stress from heat and drought. Iconic tree species of the West, such as piñon pine, aspen, and whitebark pine, may face staggering losses across much of their current range, if heat-trapping emissions continue to rise. Severe droughts may become commonplace within a few decades, causing widespread tree mortality and major changes in the character of Western landscapes.
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Photo: PixHouse/iStock
Hotter temperatures also pose threats directly to human health. For example, global warming is increasing the frequency and duration of heat waves in the West. Extreme heat brings greater risk of death from dehydration, heat stroke, heart attack, and other heat-related illnesses, particularly for less affluent neighborhoods that may lack shade trees and access to air conditioning. In addition, climate change will increase ozone pollution across many parts of the West, which exacerbates lung diseases such as asthma and can cause breathing difficulties even in healthy individuals.
Rising temperatures are leading to increased sea levels due to thermal expansion of warming oceans, as well as melting land ice (glaciers, ice caps, and ice sheets). The risks of rising seas include tidal flooding, shoreline erosion, saltwater intrusion, larger storm surges, and permanent inundation. Ocean acidification also threatens significant marine species such as oysters and Pacific salmon.
California is leading the nation in developing a comprehensive set of solutions to reduce global warming pollution in the state. The foundation for the state’s pollution-fighting activities is a 2006 law, the California Global Warming Solutions Act (AB 32), which calls for reducing the state’s global warming emissions to 1990 levels by 2020.
To help meet that goal, California is implementing numerous measures, including standards for renewable energy, a policy to scale up the use of clean fuels, requirements and incentives to increase the use of electric vehicles, and a flexible market-based cap on carbon emissions that creates economic incentives for major carbon polluters to cut their emissions. Furthermore, UCS analysis has found that California’s climate policies are saving consumers money.
California must continue to lead the way in addressing the risks of a warming climate. In 2015, UCS helped California pass a law (SB 350) that requires half of California’s electricity to come from renewable sources by 2030.UCS is now working to make sure California continues the progress it has begun by adopting a comprehensive plan to reduce carbon emissions 40 percent below 1990 levels by 2030.
Meanwhile, Washington and Oregon also have the opportunity to become leaders in addressing global warming. UCS is working in both states to make the case for holding polluters accountable for their carbon emissions by placing a price on carbon, while also advancing key solutions such as renewable energy, clean cars, and clean fuels.
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We can reduce global warming emissions and ensure communities have the resources they need to withstand the effects of climate change—but not without you. Your generous support helps develop science-based solutions for a healthy, safe, and sustainable future.
Rising temperatures are increasing wildfire risk throughout the Western U.S.
Sea level is rising—at an accelerating rate—especially along the U.S. East Coast and Gulf of Mexico.
Tell ExxonMobil to come clean—it's time to stop spreading climate science disinformation and time to stop attacking groups like the Union of Concerned Scientists.
