It's not easy to kill a full-grown tree — especially one like the piñon pine. The hardy evergreen is adapted to life in the hot, parched American Southwest, so it takes more than a little dry spell to affect it. In fact, it requires a once-in-a-century event like the extended drought of the 1950s, which scientists now believe led to widespread tree mortality in the Four Corners area of Utah, Colorado, New Mexico and Arizona. So, when another drought hit the area around 2002, researchers were surprised to see up to 10% of the piñon pines die off, even though that dry spell was much milder than the one before. The difference in 2002 was the five decades of global warming that had transpired since the drought in the 1950s. That led terrestrial ecologists at the University of Arizona (UA) to pose the question, With temperatures set to rise sharply over the coming century if climate change goes unchecked, what impact will it have on the piñon pine?
The entire Time Magazine article is here.