President Donald Trump was panned on Monday for his dismissal of his own administration's recently released climate assessment.

"In all seriousness, the willful denial and obfuscation by Trump on climate change is a crime against humanity. Billions of people will bear incalculable harm for generations to come. Much, much, much worse than possibly colluding to steal an election." —Eric Holthaus

Speaking to reporters outside the White House, Trump said of the National Climate Assessment (NCA4), "I've seen it, I've read some of it, and it's fine." Asked about the report's conclusions on the climate crisis's economic impact on the country, Trump declared, "I don't believe it."

"We cannot afford a leader who sticks his head in the sand while people suffer the consequences," said Michael Brune, executive director of the Sierra Club.

"The climate assessment, put forth by Donald Trump's own administration," Brune added, "makes it clearer than ever that if we don't act now, the catastrophic effects of climate change will reshape the United States and the world to the detriment of those alive today, and for generations to come."

Sen. Bernie Sanders (I-Vt.), for his part, said on Twitter the comment made the president "an international embarrassment and incredibly dangerous":

The fact that we have a President of the United States who doesn't believe in science is an international embarrassment and incredibly dangerous. Climate change is already causing devastating consequences. We need bold action, not denials. https://t.co/SEpIA7YYAb — Bernie Sanders (@SenSanders) November 26, 2018

"Given what we know about the president's reading habits, I wonder if the report has any pictures," said Ken Cook, president of the Environmental Working Group, in response to Trump claiming he "read some of" the government's assessment.

"By now it's the safest bet in town that when President Trump doesn't believe something is true, it is," said Cook. "None of the president's policy positions are grounded in facts, and his unfortunate decision to dismiss his own government's alarming study further demonstrates his utter ignorance when it comes to the threats climate change presents to every American."

Meteorologist Eric Holthaus weighed in on social media as well, calling "the willful denial and obfuscation by Trump on climate change... a crime against humanity":

In all seriousness, the willful denial and obfuscation by Trump on climate change is a crime against humanity. Billions of people will bear incalculable harm for generations to come. Much, much, much worse than possibly colluding to steal an election.https://t.co/IFZzlbRwfz — Eric Holthaus (@EricHolthaus) November 26, 2018

Another lawmaker commenting on Trump's denial was Rep. Pramila Jayapal:

How can @realDonaldTrump still think climate change is a “hoax”? Fact: climate change could cost the US economy upward of $500 BILLION a year. The climate crisis is a threat to our communities, economy and planet. https://t.co/K6NoqPnqnI — Rep. Pramila Jayapal (@RepJayapal) November 26, 2018

"We have the moral responsibility to #ActOnClimate, NOT bury our heads in the sand," tweeted the March for Science in response to Trump's comments: