As Population Surges, Harsh Climate Of Southwest Will Only Get Harsher

A new report from several hundred scientists underpins the impacts already being felt across the Southwest as a crippling drought grips California and states across the region struggle to allocate water to meet the demand of communities, industries and ecosystems.

“Just think of this year’s California drought — the type of hot, snowless, severe drought that we expect more of in the future,” Gregg Garfin, a lead author of the Southwest portion of the National Climate Assessment and assistant professor of climate, natural resources, and policy at the University of Arizona, told ThinkProgress in an email.

A harsh climate is nothing new for the Southwest, even before it was exacerbated by climate change. One hundred and fifty years ago, intrepid explorers like John Wesley Powell and fearless scouts like Kit Carson struggled to traverse the hot, dry, relentless terrain to get from the flat Midwestern plains to the bountiful Pacific coast.

Some seven generations later, the Southwest is as hot and dry as ever, but the traditional challenges are compounded by an abundance of urban dwellers flocking to the region for the year-round sun and outdoorsy lifestyle. The Congressionally-mandated assessment from over 300 climate scientists and experts shows how climate change could undercut this quintessentially American settling of the West — a trend that’s reached a boiling point after several hundred years of steady buildup.

The Powell survey on its second trip down the Colorado River, 1871. CREDIT: USGS

The Southwest portion of the National Climate Assessment reads like a warning for future travelers to the region:

The introduction actually notes that tourism and recreation will be significantly “affected by reduced streamflow and a shorter snow season, influencing everything from the ski industry to lake and river recreation.” All the while, the population of the area is expected to increase from 56 million people to 94 million people by mid-century, an increase of more than two-thirds.

“What they’re saying is what we’ve been seeing for several years now,” Jeremy Nichols, director of the Climate and Energy Program at WildEarth Guardians, told ThinkProgress. “Unprecedented weather, forests under stress, the writing on the wall just keep getting clearer.”

The rivers we float on face an uncertain existence, the forests we backpack in are already under stress from drought and fire.

Nichols, who is based in Golden, Colorado, said that the NCA’s findings reinforce that the great outdoors of the West, which he and his family love, are not guaranteed.

“The rivers we float on face an uncertain existence, the forests we backpack in are already under stress from drought and fire,” he said. “My colleagues who work with endangered species, rivers, and public lands are all seeing the same thing — climate change is already raising its ugly head.”

On top of the resultant emissions, the fossil fuel boom associated with fracking is also trammeling many of the remote wilderness areas across the Southwest, said Nichols. “And when it comes to water, the Rio Grande has diminished to the point where species that depend on it are facing extinction.”

Urban sprawl in Herriman Utah, overlooking Mount Timpanogos. CREDIT: flickr/Photo Dean

Whether Kit Carson was searching for an oasis to quench his thirst or John Powell was charting the unwieldy Colorado River, the lifeblood of the Southwest has always been water. This holds true in the 21st century. On top of providing water for nearly 100 million people to drink and wash with — and swim in if they have any say — agriculture is a major part of the Southwest’s economy. According to the NCA, the Southwest produces more than half the country’s high-value specialty crops. California alone produces about 95 percent of U.S. apricots, almonds, artichokes, figs, kiwis, raisins, olives, cling peaches, dried plums, persimmons, pistachios, olives, and walnuts. Excluding Colorado, more than 92 percent of the region’s cropland is irrigated, and agricultural uses account for 79 percent of all water withdrawals in the region.

The mighty Colorado River has been dammed up and down since Powell first charted its course and it now provides water and power for millions of people. However, faced with a deepening water shortage this year on an already over-allocated system, federal authorities are for the first time decreasing the amount of water flowing into Lake Mead, the country’s largest reservoir.

“For the Southwest, climate change is water change,” said Garfin. “What affects the reliability of our water supplies, and the timing of rain and snow in our region affects everything. The snow-covered peaks of Colorado, Utah, and California are the water towers of the Southwest.”

Snow water equivalent refers to the amount of water held in a volume of snow, which depends on the density of the snow and other factors. Figure shows projected snow water equivalent for the Southwest, as a percentage of 1971-2000, assuming continued increases in global emissions A2 scenario (850 parts per million of CO2 in the air). CREDIT: National Climate Assessment

The brutal drought in California has given way to an early and intense start to the wildfire season, further elicited by high temperatures and windy conditions. A recent study found that in the last 30 years in the western United States, both the number of fires and the area that they burned have increased.