THE LIGHTBULB

A bitter cold gripped Washington over the long holiday weekend as thousands came to the city for annual political marches.

Political prognosticators could have forecast this too: Yet another blustery attempt from President Trump to denounce the theory of man-made climate change because of the cold snap.

On Sunday, Trump asserted on Twitter that the United States could use "a little of that good old fashioned Global Warming" after temperatures tumbled below freezing for an extended stretch.

This is hardly the first time Trump has tried to used chilly winter weather to dismiss global warming. It isn't even the first time he has tweeted something phrased just like this

First, let's clear this up: Global warming means that average temperatures are going up globally. The vast majority of scientists studying the issue say human activity, like the burning of fossil fuels, is driving that increase. A single cold snap in one spot in the world — or even several — does not mean that thousands of climate scientists are wrong about that fact.

As Jason Furtado, an assistant professor of meteorology at the University of Oklahoma, put it to The Post's Deanna Paul: “One down day on the Dow Jones doesn’t mean the economy is going to trash.”

Or as Stephen Colbert once joked: “Global warming isn't real because I was cold today! Also great news: World hunger is over because I just ate.”

Indeed, three of the past four years — 2016, 2015 and 2017, in that order — have been Earth's warmest in more than a century of record-keeping, according to the National Oceanic and Atmospheric Administration.

In fact, one hotly debated area of climate research concerns whether shrinking Arctic sea ice is responsible for sending surges of cold air southward through North America during winter months. Much of the Lower 48 is in the middle of one of these polar vortex events right now.

And what about 2018? We don't know the official numbers because many federal workers responsible for its release are furloughed.

Meanwhile, Trump's persistent hostility toward climate science is consequential beyond the tongue-in-cheek tweets. Trump's deputies at agencies across the federal government are trying to increase the production of fossil fuels — even during the partial government shutdown.

POWER PLAYS

SHUTDOWN WATCH

“The invasion continues”: Jeanne Romero-Severson, a plant geneticist at the University of Notre Dame, was set to meet with colleagues at an annual conference to discuss the emerald ash borer, an invasive insect killing ash trees across North America. But the annual Agriculture Department invasive species conference was canceled due to the ongoing partial government shutdown, The Post’s Todd C. Frankel and Joel Achenbach report. “The invasion continues. The trees continue to die,” Romero-Severson said. “We’re losing time we cannot recover.” “The most severe costs of the shutdown may be these invisible ones — the loss of relatively obscure activities by a massive federal bureaucracy with responsibilities that stretch into unexpected corners of society,” Frankel and Achenbach write.

Wildfires don’t stop either: There were about 200 federal workers meant to begin forest fire training in Colorado Springs earlier this month who were forced to drop out. Another training in Tennessee was also canceled. “The missed training means many workers will not be qualified to help fight forest fires or can’t move on to become crew bosses or incident commanders,” Frankel and Achenbach add.

Day of service curtailed: Because of the shutdown, volunteer projects at national park sites across the country scheduled for the Martin Luther King Jr. Day holiday were derailed. “[T]he absence of help at federal sites is a loss for the National Park Service, and a letdown for volunteers,” The Post’s Michael E. Ruane reports. Karen Davis, senior vice president for advancement at the Virginia-based Student Conservation Association said it “equates to a little more than 800 hours of service that they would have been putting in for the national park.”  

Another missed chance: And with national park staff still furloughed, the bare bones staffing at parks across the country left them vulnerable. “The high visitation at some national parks over the weekend also highlight a missed opportunity. Holiday weekends typically are big revenue generators,” The Hill reports. John Lauretig, executive director of Friends of Joshua Tree, “estimated that a three-day weekend at Joshua Tree could generate close to $100,000.”

THERMOMETER

— New Pentagon report highlights climate risk to military installations: A report out last week from the Defense Department found climate change is putting about two-thirds of U.S. military installations at risk. “Examining 79 military installations, the report finds that 53 already suffer from ‘recurrent flooding,’ 43 have been exposed to drought, and 36 to risk from wildfires,” The Post’s Brady Dennis, Chris Mooney and Missy Ryan report. “And it finds that risks like these could extend to more installations in the coming years.” They add the 22-page document settles a long-standing sense that the military “is well attuned to how the planet is changing due to the burning of fossil fuels.”

But critics say the report is short on details: “It seems like they have not made it past anecdote to analysis,” said John Conger, director of the Center for Climate and Security and former acting assistant secretary of defense for energy, installations and the environment. “It’s concerning to me because Congress was looking for the department’s best judgment on how to prioritize the risks.”

—  A “tipping point” in Greenland: The island’s massive ice sheet is melting so fast that it may have hit a “tipping point,” according to a new study published Monday, the latest in recent research that suggests the impact of warming is outpacing what scientists previously thought. “The Arctic is warming at twice the average rate of the rest of the planet, and the new research adds to the evidence that the ice loss in Greenland, which lies mainly above the Arctic Circle, is speeding up as the warming increases,” the New York Times reports. “The authors found that ice loss in 2012 was nearly four times the rate in 2003, and after a lull in 2013-14, it has resumed.”

— Key West to ban sunscreens that may harm coral reefs: The Key West City Commission unanimously voted last week to ban sunscreens that can harm coral reefs. The measure, which bans sunscreens with oxybenzone and octinoxate, must be reviewed and passed by the commission a second time before it becomes law, Gwen FIlosa reports for The Post. “This is to me something we need to do in this community to protect our economy," said City Commissioner Jimmy Weekley, one of the measure’s sponsors. "What if we don’t pass this and three to five years down the road we have no reef?”

OIL CHECK

— PG&E’s wildfire woes: U.S. District Court Judge William Alsup in San Francisco tentatively ruled that the electric utility’s equipment was “the single most recurring cause of the large 2017 and 2018 wildfires.” The judge noted "the susceptibility of PG&E’s distribution lines to trees or limbs falling onto them during high-wind events,” NBC News reports. PG&E said last week it was reviewing the tentative conclusion, adding that it is “committed to complying with all rules and regulations that apply to our work."

— California lawmakers face tough question: Following PG&E’s decision to file an intention to declare bankruptcy, lawmakers must decide whether to save the utility with a history of fatal safety missteps that’s critical to the state’s clean energy goals, The Post’s Scott Wilson reports. “At the moment, there is little political motivation to assist PG&E, whose bankruptcy announcement prompted the company to fence-off the entrance to its $1 billion San Francisco headquarters for fear of demonstrations,” he writes. “The answers in the capital will provide both short-term and long-term guidance for how the nation’s most populous state, and in many ways its most pioneering on the issue of climate change, will ensure that publicly traded utilities remain economically viable as California enters the age of the endless fire season."

— Tesla announces plan to cut 7 percent of its workforce: The automaker announced it will reduce its workforce by 7 percent as part of an effort to make its Model 3 sedan more accessible. “In a memo to employees, chief executive Elon Musk said the layoffs are a way to boost margins as the company plans to ramp up production on the Model 3 while also bringing down the price,” The Post’s Taylor Telford reports. “Tesla declined to specify how many employees will be affected, but it could be more than 3,100. Tesla had a workforce of 45,000 in October, according to a tweet from Musk. Last year, the company grew 30 percent — more than the company can support, Musk said in the memo.”

DAYBOOK

Coming Up

  • Johns Hopkins University’s China Studies and Energy, Resources & Environment Programs holds a forum on sustainable transport and urban prosperity in China on Wednesday.
  • The Energy Department’s Office of Energy Efficiency & Renewable Energy is scheduled to hold a call on energy efficiency and resiliency on Thursday.
  • The United States Energy Association holds its annual State of the Energy Industry Forum on Thursday.
  • The World Resources Institute is scheduled to hold an event on driving equitable climate transitions on Jan. 31.
EXTRA MILEAGE

— In case you missed it: Kevin Ambrose compiled for The Post photos of Sunday night's "Super Blood Wolf Moon":