Extreme heat has smashed temperature records around the country and around the world in the past week alone.
But if we fail to significantly curb emissions of carbon pollution — the path set forth by President Trump’s climate policies — then these severe and deadly heatwaves will become the normal summer weather over the next few decades.
Typical five-day heat waves in the U.S. will be 12°F warmer by mid-century alone, according to the U.S. National Climate Assessment (NCA), which the White House itself reviewed and approved last November.
Other studies also show the devastating heat-related impacts the nation and the world face from Trump’s policies of abandoning the Paris climate deal, undoing Obama-era climate rules, and boosting carbon pollution.
For instance, America (and much of the world) will start seeing monster “humid heat waves” — where the heat index hits a fatal 131°F — every other year by century’s end.
Heat wave records have been falling at an astonishing rate in recent days around the country and around the globe. The brutal heat has spurred wildfires, water shortages, asthma attacks, power emergencies, and the like.
In many cases, the records were not simply beaten, they were obliterated. As NOAA reported in Southern California, where temperature records go back 140 years, records for July 6 were disintegrated by 14°F in downtown Los Angeles and Camarillo, and by 16°F in San Luis Obispo.
In Van Nuys, it hit 117°F on Friday, destroying the previous record for the day (99°F) by an astounding 18°F — and that record was just set last year.
We know that human-caused (anthropogenic) carbon pollution and global warming is now the leading factor in such records. A 2016 study in Nature Scientific Reports, led by climatologist Michael Mann, concluded, “In summary, our results suggest that the recent record temperature years are roughly 600 to 130,000 times more likely to have occurred under conditions of anthropogenic [climate change] than in its absence.”
The congressionally-mandated NCA, the “authoritative assessment of the science of climate change, with a focus on the United States,” projects a stunning 8°F to 10°F average warming over the interior of this country under the report’s “higher emissions” of carbon pollution scenario (see chart).
PROJECTED CHANGES IN ANNUAL AVERAGE TEMPERATURES (2070–2099) WITH STRONG CLIMATE POLICIES (LEFT) AND WITH PRESIDENT TRUMP’S CURRENT POLICIES (RIGHT). CREDIT: NATIONAL CLIMATE ASSESSMENT
But the NCA also makes clear that temperature extremes rise at an even faster rate than average temperatures.
For instance, the average temperature over the country is projected to rise about 9°F by late in the century (2071-2100) in the high emissions scenario where the Paris climate agreement fails and climate action stalls. But the temperature of the warmest five-day period during a once-in-a-decade heat wave is projected to rise some 12°F just by mid-century (2036–2065) in that case.
The NCA scientists explain that to achieve the low-emissions scenario, not only does every nation — including ours — have to meet its Paris climate pledge. But we all also have to keep ratcheting down the targets “with continually increasing ambition” until global emissions of carbon pollution are near zero by century’s end.
Current extreme heat waves — and the droughts and wildfires that accompany them — are already wreaking havoc on this country and the world.
Tragically, Trump’s policies will make such heat waves simply our normal climate, and create new monster heat waves with catastrophic impacts.
