National Average Economic Damage in USA
Source: Estimating Economic Damage from Climate Change in the United States, Science, June 2017
The day after Thanksgiving, the Trump administration released the Fourth National Climate Assessment (NCA4), which detailed the latest estimates of the impact climate change would have on the United States. Media coverage following the release zeroed in on one statistic, which showed that climate change would “knock as much as 10 percent off the size of America’s economy by century’s end.” Critics—the White House included—used the statistic to paint the report as “radical” and “extreme.”
What’s the truth behind the stat? The stat comes from a Science magazine study co-authored by Amir Jina, an assistant professor at the University of Chicago Harris School of Public Policy. As the chart shows, in one sense the 10 percent is an overestimate—representing the estimated damages for warming of 15°F above pre-industrial levels, which is unlikely. If the world adheres to the goals of the Paris Climate Accord, then a more moderate warming scenario would likely play out, with warming of between 2°F to 7°F. Under this outlook, the nation’s GDP would shrink by about one percent to four percent. At the same time, the chart shows how climate change will impact health, labor and agricultural productivity, energy demand, crime and coastal property. These are important, but leave out many other effects that could be as dramatically affected or worse, such as ecosystem loss, changes to water availability, wildfires, migration, and many others. Once all the impacts across the economy are tallied, 10 percent would likely be an underestimate.