Every three weeks, the U.S. experiences an extreme weather event in which damages and costs top $1 billion.
That compares with every four months in the 1980s, when adjusted for inflation, according to the latest installment of the U.S. National Climate Assessment released November 14.
Created in 1990, the national climate assessment is mandated by law and is produced every four years, though it sometimes gets delayed. This latest version—the fifth—expands on findings from the last assessment in 2018 and was written by more than 750 experts and reviewed by 14 federal agencies.
For the first time, the assessment includes a separate chapter on the economic impacts associated with climate action, noted Amrith Ramkumar of The Wall Street Journal. The chapter “really paints a much broader picture of the ways in which climate change is affecting daily life,” said Delavane Diaz, a principal team lead at the Electric Power Research Institute and a co-author of the report. To enable people to see the impacts of climate change in their city and state, the Biden administration has created an online tool.
Due to global warming, average temperatures in the United States are rising about 60 percent faster than they are in the world as a whole. Every part of the country is feeling the effects of the warming planet, the report finds. Rising fatalities from extreme heat in the Southwest. Earlier and longer pollen seasons in Texas. Northward expansion of crop pests in the Corn Belt. More damaging hail storms in Wyoming and Nebraska. Stronger hurricanes in Puerto Rico and the Virgin Islands. Shifting ranges for disease-spreading ticks and mosquitoes in many regions.
For every 1 degree Fahrenheit that the planet warms, the U.S. economy’s growth each year is 0.13 percentage points slower than it would be otherwise, according to the report. As The New York Times’ Raymond Zhong pointed out, that seemingly small effect can add up, over decades, to a sizable amount of forgone prosperity.
The report concludes that Americans’ efforts have mostly been “incremental” instead of “transformative”: installing air-conditioners rather than redesigning buildings, increasing irrigation rather than reimagining how and where crops are grown, elevating homes rather than directing new development away from floodplains. About 40 percent of the U.S. population lives in coastal communities exposed to sea level rise, and millions of homeowners could be displaced by the end of the century, according to the assessment.
Switching to zero-carbon energy could reduce air pollution enough to prevent 200,000 to 2 million deaths by 2050, the report says.
The National Climate Assessment is extremely influential in legal and policy circles, and affects everything from court cases about who should foot the bill for wildfire damage, to local decisions about how tall to build coastal flood barriers, NPR reported. "It really shapes the way that people understand, and therefore act, in relation to climate change," says Michael Burger, the director of the Sabin Center for Climate Change Law at Columbia University.