Kate Marvel writes:

It rains in the Amazon because the trees want it to. There is plenty of moisture in the oceans that surround the continent, but there is also a hidden reservoir on the land feeding an invisible river that flows upward to the sky. The water held in the soil is lifted up by the bodies of the trees and lost through the surfaces of their leaves to the atmosphere. The local sky plumps with moisture, primed for the arrival of the seasonal rains driven by the annual back-and-forth march of the sun’s rays. As climate scientist Alex Hall puts it, the trees are co-conspiring with the sky to attract an earlier monsoon.

This is the decade we knew we were right. It began with the warmest year on record; it then broke that record at least five times. Carbon dioxide in the atmosphere reached levels unprecedented since humans were hominins. There were droughts and floods and brutal heat waves. Coral reefs turned white and gave up. Australia is in drought. The Amazon is on fire.

Nothing is eternal and nothing is infinite. There were once forests in the Sahara—if not quite the Amazon, still lush and tropical, clustered around the largest freshwater lake on the planet. In geologic time, this was practically yesterday: less than ten thousand years ago. The lake is mostly gone now, vanished in the span of a few hundred years. In its place there is nothing but dust.

The changes now are different. We expected most of them, and they are occurring with a terrifying rapidity that is no more reassuring because it is easily understood. We have known that carbon dioxide traps heat for over a hundred years. We have known that we are changing the planet for decades now. There is no consolation in being right. [Continue reading…]