Even more dramatic was CNN’s headline, screaming that “climate change will shrink [US] economy” by 10 percent, a figure also repeated on The New York Times front page.
Actually, the UN’s climate scenarios envision US GDP per capita will more than triple by the end of this century, so this 10 percent reduction would come from an economy 300 percent larger than it is today. A slightly smaller bonanza, in other words.
But the 10 percent figure is itself dodgy. It assumes that temperatures will increase about 14 degrees Fahrenheit by the end of the century. This is unlikely. The US climate assessment itself estimates that, with no significant climate action, American temperatures will increase by between 5 and 8.7 degrees. Using the high estimate of 8.7 degrees, the damage would be only half as big, at 5 percent.