Scott Stephens, a professor of environmental science, policy and management at Berkeley and co-director of Berkeley Forests, joins SHORT WAVE, the daily science podcast from NPR with an urgent message: They've been here 1,500 years, and each tree maybe survived 60, 70, 80 fires. That's incredible. And then one fire comes in 2020. And all of a sudden, they're gone. That is a travesty. Unless we see some regeneration at some of these sites, my goodness, you're not going to see sequoia here.