“The Southwest is already experiencing the impacts of climate change.” That is one of the conclusions of the Third National Climate Assessment, released today. For those of us who live, work, and recreate in the Southwest, that conclusion rings true. The Assessment, which Gary Graham and I contributed to in its early stages, describes impacts to specific sectors across the nation, such as agriculture, forests, the energy sector, and human health, among others, as well as broad regional impacts. It provides a roadmap for the type of adaptation that’s likely to be needed, and underscores the urgency to mitigate our emissions.

In the Southwestern region, reduced water availability or projected changes in snowpack (“snow water equivalent”) is one of the most critical impacts. Snow water equivalent, which is the amount of water in the snowpack at a critical date (April 1 for much of the Interior West), is projected to decline by 13% in the Upper Colorado River basin by mid-century, relative to the recent average. In California, which is in the thick of one of the worst droughts on record, snow water equivalent is projected to be just 66% of the historic average by mid-century. In river systems like the Colorado, there is little or no “wiggle room” – less water available means a city, farmer, or the environment gets less water. Indeed, some of the most severe impacts may be felt by the Southwest’s agricultural sector.

Figure 20.2, featured in the Southwest Regional summary.

 Figure 20.2, featured in the Southwest Regional summary project snow water equivalent

Reading the litany of current and future impacts in the assessment – earlier snowmelt, hotter summers, more frequent and intense droughts, increased wildfires, along with the secondary impacts on human health and environmental resilience – makes the challenge seem daunting. But along with the report released today, the White House is emphasizing the actions the administration is taking to curb these impacts. Most importantly, in June the Environmental Protection Agency will release draft standards for greenhouse gas (GHG) emissions from existing power plants, which account for 33% of our nation’s GHG emissions.

Western Resource Advocates has been working with states, utilities, and other stakeholders to prepare for these regulations. Several western states, such as Colorado, have made significant investments in renewable energy, energy efficiency, and retiring coal units. WRA’s model for meeting those standards would provide states and utilities flexibility in meeting emissions reductions (e.g., renewable energy and energy efficiency can count toward reductions), credits utilities or states (such as Colorado) for their early actions, and ensures that carbon reductions are real and verifiable. EPA’s forthcoming standards are perhaps the best chance we have at curbing our nation’s greenhouse gas emissions, and avoiding the worst of the impacts described in the National Climate Assessment. That, in turn, protects our region’s land and water resources, which westerners have said – rather resoundingly – they cherish.