Driving through southern Utah today from Arizona, we saw thousands of pine trees that have been killed by the voracious pine beetle. Normally, severe winter cold will slow down the pine beetle, but winters lately in the American West have been warmer, another effect of climate change.
Treehugger has a photo and more information on the apparently unstoppable march of the pine beetle.
Much of the damage you saw was probably from prior years, as dead trees may continue to stand for a decade or more. However, if warming climate were to blame for the increasing infestation, one would think that last winter’s extreme cold might have killed them off. Here on the Parowan Valley floor, we had the coldest winter in decades– ten nights in a row hit between -25 and -32.
I can find no reports to either confirm or disprove any change in the bark beetle infestation as a result of the unusually cold winter. But I did find a scientific report siggesting that this species of bark beetle has the ability to increase its cold tolerance. See it here.