Climate change will be a problem for everyone alive today, according to the National Climate Assessment. The U.S. federal government’s latest roundup of climate science is now in its fourth iteration and is letting readers know that climate change could make life in the Western U.S. difficult.
According to KUNC, the report is a product of the U.S. Global Change Research Program, a combination of 13 federal agencies. Its publication is required by law, according to KUNC.
In the assessment, climate scientists say with confidence that warm temperatures are reducing the water content of mountain snowpack and the flows of rivers and streams that depend on the snowmelt. The landing page of this chapter of the report shows a photos of low water levels at Lake Mead, the nation’s largest reservoir.
The Colorado River feeds the lake, according to KUNC. The watershed provides drinking and irrigation water for 40 million people across the U.S. The climate is also leading to more droughts, increasing the risk of severe floods, weakening infrastructure projects and depleting groundwater, according to the report.
According to the report, gaps between water supplies and demands in the desert southwest with continue to grow without coming up with ways to manage water and cut greenhouse gas emissions.
The report confirmed what many scientists already know: water security in the U.S. is in jeopardy. According to the report, the entire southwest region could see its average annual temperature rise an additional 8.6°F by 2100. Southern parts of the region could see their summers extend well into the spring and fall, with 45 more days each year where temperatures would climb higher than 90°F.
This warming means areas of the southwest are at risk for long term drought and will be seeing the risk increase for prolonged droughts in the future. According to KUNC, droughts can materialize from a lack of precipitation and a rise in temperature. Each drought product of particular circumstances, according to the report. The droughts can be intensified by dwindling groundwater, which acts as a buffer against scarce water supplies above ground in some regions.
Studies have shown that the warming temperatures in the Colorado River Basin are causing a decline in river flows and increasing evaporation in streams and reservoirs, according to KUNC. During the driest period on the Colorado River, between 2000 and 2014, climate change moved the scales toward higher temperatures resulting in between 17% to 50% reductions in streamflow.