“Now’s a good time to go visit national parks with big trees,” said Nate McDowell, an earth scientist at the Pacific Northwest National Laboratory and the lead author of a paper forecasting that in southwestern US forests more than half of conifers, the dominant type of trees, could be killed by 2050. “It’s like Glacier national park – now’s a good time to see a glacier before they’re gone.”
Since 2010, 129m trees are estimated to have died in California’s national forests, as a result of a hotter climate, insects and other factors. Astonishingly, 48.9% of all trees in a comprehensive study of the southern Sierra Nevada mountain range were killed.
Forests absorb around one-quarter of all human carbon emissions annually, and increasingly there are worries that if forests die back they will switch from storing carbon to emitting it, because dead trees will release all the carbon they have accumulated.