Climate scientists are responding to President Donald Trump's comments on the fourth National Climate Assessment — a publicly reviewed, congressionally mandated climate assessment put together by 13 government agencies and a team of 300 experts.

On Monday, Trump was asked by reporters about the assessment — specifically the economic impact — to which he replied, "I don't believe it." Press Secretary Sarah Sanders also dismissed the report during Tuesday's press briefing.

Katharine Hayhoe, a climate scientist, who helped author the report, responded to the Trump administration via Twitter.

"The warming oceans, melting ice sheets, rising sea level, worsening droughts, floods, superstorms, and wildfires—they don’t care what Trump thinks," climate scientist Michael Mann told INSIDER. "And we are increasingly endangered — as a civilization — by this one man’s apathy, ignorance and malice."

Climate scientists are responding to President Donald Trump's comments on the fourth National Climate Assessment — a congressionally-mandated climate assessment put together by 13 government agencies and a team of 300 experts. The most recent assessment was released on Friday, November 23, and what it portends is dire: a potential economic cost of hundreds of billions of dollars, sea-level rise, extreme weather events, and insect-borne disease.

On Monday, Trump was asked by reporters about the assessment — specifically the economic impact — to which he replied, "I don't believe it." He also stated that it was "important" to him to have clean air and water.

He repeated these claims in a wide-ranging interview with the The Washington Post published on Tuesday.

"One of the problems that a lot of people like myself, we have very high levels of intelligence but we’re not necessarily such believers," Trump told The Post about the report. "You look at our air and our water, and it’s right now at a record clean."

"As to whether or not it’s man-made and whether or not the effects that you’re talking about are there," he continued, "I don’t see it."

Press Secretary Sarah Sanders also dismissed the report during Tuesday's press briefing.

"We think that this is the most extreme version and it’s not based on facts," Sanders said in response to a reporter's question about the report. "It’s not data driven. We’d like to see something that is more data driven. It’s based on modeling, which is extremely hard to do when you’re talking about the climate."

She also reiterated Trump's talking points on clean air and water: "The president’s certainly leading on what matters most in this process, and that’s on having clean air, clean water."

Read more: 12 scary takeaways from the climate report the Trump administration dropped on Black Friday — and one reason for hope

Climate scientists strongly disagree with Trump's comments

Katharine Hayhoe, a climate scientist, who helped author the report, responded to the Trump administration via Twitter. Hayhoe is a professor of political science, director of the Climate Science Center at Texas Tech University, and a part of the Department of Interior's South-Central Climate Science Center,

"The Fourth US National Climate Assessment was released on Friday," Hayhoe tweeted on Tuesday. "Since then, a number of politicians + pundits have made statements about it that are not accurate. As an author, I'm here to set the record straight. Here we go!"

First, Hayhoe responded to Sanders's, "most extreme version" comment.

"No: the report considered a very broad range of scenarios, from one where carbon emissions go negative to one where they continue to grow," Hayhoe tweeted citing chapter two of the report. She also goes on to point out where the report made an effort to show what the different scenarios would mean in the future.

National Climate Assessment National Climate Assessment

Hayhoe also states that the report was "publicly reviewed" and that "authors were required to respond to each comment individually." Both comments and responses are available for the public to read, and she stated that there are full citations and documentation in the report.

She does concede that Sanders is right on one count. Sanders told the press that "modeling the climate is an extremely complicated science that is never exact."

"That is absolutely true," Hayhoe says. "And that’s why, in the chapter I wrote with [climate and sea-level scientist Bob Kopp] called 'Potential Surprises,' this conclusion is so worrisome."

It's actually possible that the climate models will "underestimate temperature change during warm paleoclimates" suggesting that "climate models are more likely to underestimate than overestimate the amount of long term future change."

Hayhoe also responded to President Trump's comments that he does not believe the report.

"But climate science isn't a religion: it's real, whether we believe it or not," she writes. "If our decisions are not based in reality, we are the ones who will suffer the consequences." (You can read her full thread here.)

Michael Mann, a professor of atmospheric science and director of the Earth System Science Center at Penn State University, echoes this sentiment.

"Climate change is real, human-caused — and increasingly dangerous — regardless of what one deeply ignorant and misguided individual might happen to think," Mann said in an email to INSIDER in response to Trump's comments. "The warming oceans, melting ice sheets, rising sea level, worsening droughts, floods, superstorms, and wildfires—they don’t care what Trump thinks. And we are increasingly endangered — as a civilization — by this one man’s apathy, ignorance and malice."

What Hayhoe recommends.

As Business Insider's Dana Varinsky reported last week, there is some hope when it comes to adapting to and mitigating the impacts of climate change — and the report has a chapter on each response.

For those wondering how one person can make an impact, or if it's too late to mitigate climate change, Hayhoe has a few recommendations:

INSIDER contacted Hayhoe for a deeper explanation on her tweets, and we'll update if we hear back.