You can see the dead and dying from the air.
In coastal Alaska and British Columbia, swaths of yellow cedar trees are losing their needles and withering away. Under normal conditions, these economically and culturally valuable trees can live 1,000 years or more, but enough of them are dying that the trees are now being considered for protection under the US Endangered Species Act.
A yellow cedar’s demise is not instantaneous. It takes years for a tree to die, slowly, from the inside out. It has similarly taken a long time to prove exactly why these trees are dying.
After three decades of searching, scientists have finally resolved the cause: climate change.