In this May 23, 2016 photo, arborist Jim Clark inches up a giant sequoia to collect new growth from its canopy in the southern Sierra Nevada near Camp Nelson, Calif. Clark volunteers with Archangel Ancient Tree Archive, a nonprofit group that collects genetic samples from ancient trees and clones them in a lab to be planted in the forest. The group believes the giant sequoias and costal redwoods are blessed with some of the heartiest genetics of any trees on earth and that propagating them will help reverse climate change. (AP Photo/Scott Smith), APTOPIX