report

the main reason neither Congress nor much of the American public cares about global warming is that, as problems go, it seems remote. Anyone who reads the latest National Climate Assessment, released on Tuesday, cannot possibly think that way any longer.

The study, produced by scientists from academia, government and the private sector, is the definitive statement of the present and future effects of climate change on the United States. Crippling droughts will become more frequent in drier regions; torrential rains and storm surges will increase in wet regions; sea levels will rise and coral reefs in Hawaii and Florida will die. Readers can pick their own regional catastrophes,

Taken alone, the small-scale transformation in my yard doesn’t matter all that much. But a constellation of small patches of milkweed, connecting one neighborhood to the next, might mean the difference between life and death for the monarchs. We need to start thinking not just about what used to be, but what could be. It’s going to take a lot of work. But it sure beats despair. The author of “My Backyard Jungle: The Adventures of an Urban Wildlife Lover Who Turned His Yard Into Habitat and Learned to Live With It,” and an associate professor of creative writing at the University of South Carolina.

Nature can survive far more than what we can do to it and is totally oblivious to whether homo sapiens lives or dies in the next hundred years. Our concern should be about protecting ourselves — because we have only ourselves to protect us. Alan Lightman is a physicist who teaches humanities at M.I.T. His most recent book is “The Accidental Universe.”