Earth Notes: In the Southwest, Climate Change Is Global Warming

Mar 30, 2016

Most scientists today prefer the term “climate change” to “global warming,” since human-caused changes to the Earth’s atmosphere produce many changes beyond temperature. But especially in the southwestern states “warming” is an apt term too.

Lake Mead
Credit Ethan Miller/Getty

According to a new analysis of monitoring data by Climate Central, the U.S. is warming across the board—but to different extents in different places. And the effect varies by season, too.

For the Southwest, the most notable warming has come in the spring and fall. In fact the Four Corners states, plus Nevada, have experienced more springtime warming than any other states in the lower 48. No state has warmed more in the spring than Arizona, where Phoenix this February recorded its earliest-ever 90-degree day.

Snow cover, or the lack of it, is contributing to the rising tide of heat. As temperatures climb, in some regions snow is replaced by rain.

In the Southwest, where spring temperatures are rising fastest, light-reflecting snow packs are melting earlier, exposing more of the darker ground beneath. That’s increasing solar energy absorption in a feedback loop that can send late-winter and spring temperatures soaring even higher.

And the higher temperatures, in turn, affect other ecological factors, from water supply to the blooming of flowers to the occurrence of wildfires.

Is there a place to go for those who crave cold? Some measurements show that temperatures in parts of Antarctica may be dropping—cold comfort for those worried about where the weather’s headed.