A group of Republican senators are calling for an investigation of the National Science Foundation (NSF) over a program that "[turns] television meteorologists into climate change evangelists," according to a Wednesday press release from the office of Sen. Ted Cruz (Texas).

Cruz, along with Sens. Rand Paul (Ky.), James Lankford (Okla.) and Jim Inhofe (Okla.), all signed a letter to NSF Inspector General Allison Lerner to investigate the NSF's grant-making process, specifically the $4 million in federal funding the agency gave to the nonprofit news organization Climate Central.

They targeted several grants awarded to Climate Central's "Climate Matters" program, which trains meteorologists to address climate issues and encourages them to communicate climate science to the public.

The program has been in place since 2012 and has educated more than 500 meteorologists about global warming, according to NBC News.

NBC News noted that the program is working:

So far, the efforts have paid off. The number of stories on global warming by television weather people has increased 15-fold over five years, according to data from the Center for Climate Change Communication at George Mason University. If the trend continues this year, there will be more than a thousand stories that touch on climate delivered during local TV weathercasts, up from just 55 such climate stories in 2012.

The senators, however, argue that the reporting by meteorologists is not science but "propagandizing."

"Research designed to sway individuals of a various group, be they meteorologists or engineers, to a politically contentious viewpoint is not science—it is propagandizing. Such efforts certainly fail to meet the standard of scientific research to which the NSF should be devoting federal taxpayer dollars," the wrote.

Climate Central CEO Ben Strauss dismissed the GOP senators' claims, telling NBC News via email: "Climate Central is not an advocacy organization, and the scientific consensus on climate change is not a political viewpoint."

While the vast majority of climate scientists are convinced about human-caused global warming, the partisan divide over the issue is growing wider—and it may be due to President Donald Trump.

A recent Gallup poll found that after a year of President Trump—who thinks global warming is a "hoax," dropped climate change from a list of top national security threats, and made it known that America is at odds with the rest of the world by withdrawing from the 2015 Paris agreement—Republicans have become more skeptical than ever about climate change.

The poll found that only a third of Republicans said they worry about climate change or even acknowledge that it has already begun. Seven in 10 Republicans think the seriousness of global warming is exaggerated in the news. The percentage of Republicans who affirm the scientific consensus of global warming is down 11 percentage points since last year.