We have just experienced a monthlong heat wave that shattered records across the American West.
Temperatures topped 120 degrees in Los Angeles County. Red flag warnings of extreme fire danger are posted from the Mexican to the Canadian border. Bay Area smoke has been so thick that San Franciscans have had to check their watches to tell whether it is night or day. In Oregon, fire has been consuming entire towns at the rate of three or four per night.
These hellish conditions have spawned megafires so large and intense that they create their own lightning, their own tornados, and defy all efforts of men and machines to control them.
This isn’t just a stroke of stupendous bad luck. A century of gorging on fossil fuels has already changed the climate of the American West, making it vastly more prone to drought and fire. Climate scientists point out that seemingly small increases in atmospheric temperature, if sustained over time, have profoundly harmful consequences, one of which has become the periodic turning of the American West into an inferno.
Climate scientists tell us that permanently heating the climate by just 2 degrees Celsius (3.6 degrees Fahrenheit) greatly intensifies heat waves, droughts, storms and sea level rise, causing widespread economic and ecological harm. In the 2015 Paris accords, 195 nations heeded these warnings and committed to keeping global warming to less than 2 degrees Celsius.
Parts of California, Oregon and Utah have already permanently passed the 2 degrees Celsius benchmark.
Research published by the American Geophysical Union directly connects global fossil fuel consumption with the heat, drought and fire now destroying vast swaths of the American West. The study explains that rising air temperatures suck moisture from soil and vegetation, a process called evapotranspiration. By increasing evapotranspiration, each 1 degree Celsius rise in air temperature increases the water that a forest needs to stay viable by 20%.
At the same time, rising air temperatures reduce the water available to the forest by converting winter snows to rain and lengthening and intensifying summer dry seasons. Through these processes, a modest increase in the temperature of a forest environment exponentially increases the likelihood that it will burn.
The AGU study notes that since the 1970s, California’s summers have become modestly hotter (by 1.4 degrees Celsius). Over this time, California’s annual wildfire burn area has increased a catastrophic eightfold. The study shows that this warming is responsible for more than three-fourths of the disastrous increase in California’s forest fire activity, due to increases in moisture evaporation and the conversion of winter snows to rain.
Utah is vulnerable to climate change in nearly all the same ways that California is (desert climate, reliance on dwindling mountain snowpack, equivalent amount of permanent warming). Climate warming is drying up Utah’s forests and its primary water sources, setting up the state for the same catastrophic fires we see along the Pacific Coast.
For example, annual Colorado River flows since 2000 are 28% below its 100-year average. Permanently higher regional temperatures have caused roughly a third of that shortfall. If regional climate warming continues unabated, flows of the Provo and Bear rivers will suffer similar declines. Utah will have to expropriate the majority of the waters that feed the Great Salt Lake to meet the needs of its burgeoning population, which will eventually expand hardpan Salt Flats to the foot of the Wasatch Front.
Utah faces consequences from climate change that are as dire as California’s. To mitigate that harm, one would think that Utah would commit itself to making its economy carbon neutral by 2045, as California, Colorado and New Mexico have done, and would be asking the nation to do the same.
Malin Moench, Holladay, has degrees in law and economics from the University of Utah. After 37 years of legal analysis and econometric modeling work for the federal government, he now volunteers for the Citizens' Climate Lobby.