科学美国人60秒:Heat Will Hit America's Poorest Worst

In President Trump's June 1^st speech withdrawing the U.S. from the Paris Climate Accord, he claimed the climate agreement was costing American workers. In a whole lot of ways: "In terms of lost jobs, lower wages, shuttered factories, and vastly diminished economic production."

Of course, doing nothing about climate change is an option. But what is the economic price…of that choice? A team of economists and scientists set out to answer that question, by linking up economic and climate models to estimate how much warming temperatures could cost the U.S. economy. 

And they found that for every degree Celsius the temperature goes up? It docks the U.S. gross domestic product, the GDP, by 1.2 percent. 

But that economic penalty will not be evenly applied. Because the southern U.S. is already much poorer than the northern U.S. today. Oh, and it's hotter, too. "You know, if you're already a really hot location, heating up is really harmful." Solomon Hsiang, an economist at UC Berkeley. "Going from 70 to 75 isn't nearly as bad as going from 90 to 95."

Add in more hurricane damage, smaller crop yields, lost jobs, an increase in death and disease—and the analysis finds that climate change could eat up 20 percent of the poorest counties' income by the end of the century.

"Effectively we're harming the poorer populations and helping the wealthier northern populations. So this means climate change can actually increase inequality within the United States." The study is in the journal Science. [Solomon Hsiang et al, Estimating economic damage from climate change in the United States]

Warming temperatures probably won't help President Trump reach his forecasted three percent growth rate for the U.S. economy, either. "You know, this is essentially going to slow down the growth rate gradually." In other words: it won't be a good climate for negotiation.

—Christopher Intagliata