Trump tweeted: In the East, it could be the COLDEST New Year's Eve on record. Perhaps we could use a little bit of that good old Global Warming that our Country, but not other countries, was going to pay TRILLIONS OF DOLLARS to protect against. Bundle up!
Before sending that message, Trump had not sent any tweet containing the phrase "climate change" or "global warming" since becoming president, according to the Trump Twitter Archive.
In contrast, two years ago during the chilly winter of 2015, Trump sent off at least nine tweets holding up the thermometer as evidence global warming can't be happening.
- It's record cold all over the country and world - where the hell is global warming, we need some fast!
- Record low temperatures and massive amounts of snow. Where the hell is GLOBAL WARMING?
Indeed, temperatures some 15 to 30 degrees lower than normal will grip much of the United States east of the Rockies for the next seven to 10 days. The cold snap will likely be the most frigid since February 2015 - when Trump last cast doubt on climate science because it was cold outside.
But a single cold streak does not prove climate change is fake. Man-made global warming, as the name suggests, refers to the steady rise of average temperature of Earth's climate system due to the buildup of heat-trapping gases in the atmosphere. Indeed, at the moment much of the rest of world is warmer than normal even if a portion of the United States is chilly.
And from January to November, the Lower 48 experienced the third warmest period on record, according to the National Oceanic and Atmospheric Administration.
That added energy to Earth's climate system alters more than just average temperatures. One active and heavily debated area of climate research concerns the degree to which climate change causes the jet stream encircling the Arctic to wobble southward, and send a surge of cold air across portions of North America - as it is now.
Right now, the jet stream is crashing south in the eastern half in the continent while surging northward in the west half. That phenomenon, called the North American Winter Dipole, is strangely enough simultaneously responsible for freezing temperatures in the East and the roasting temperatures in the West, which are fueling recent forest fires in California.
Brian Brettschneider, a climatologist based in Alaska, calculated that New Year's Eve would be third coldest since 1948. In the eastern United States, 2014 was actually a hair colder than the current forecast. His basis for comparison is the forecast from the Global Forecast System forecast model, which is the National Weather Service's main prediction model, sometimes called the American model.
Trump's tweet is reminiscent of the remarks Sen. James Inhofe, R-Okla., made on the Senate floor in February 2015, after a Washington snowstorm. The senator, who has consistently questioned the connection between human activity and climate change, brought a snowball onto the floor and recalled how his children had built an igloo.
"It's very, very cold out. Very unseasonable," remarked Inhofe, who chaired the Senate Environment and Public Works Committee at the time.
Referring to the snowball as an example of "scientific analysis," he threw it at the sitting Senate president, and declared, "So, catch this."