In a new digital ad released Friday, a group trying to marshall millennials' support for Democratic presidential nominee Hillary Clinton criticizes Libertarian Party candidate Gary Johnson for his views on global climate change.

The ad is noteworthy since it targets a third-party candidate who is garnering about 10 percent support in national polls, but who is drawing most of that following from voters under the age of 50.

NextGen Climate, funded by hedge fund billionaire and environmental activist Tom Steyer, is seeking to bolster millennials' support for Clinton.

Polls show her failing to generate nearly the same enthusiasm among young voters as they had for Barack Obama in 2008 and 2012. NextGen Climate is putting $100,000 behind the ad and released it first to Mashable on Friday.

Climate change could be a wedge issue that keeps millennials from going with a third party candidate, since younger people are overwhelmingly in favor of acting to stem the growing impacts from global warming.

For example, a 2015 poll by the Harvard Institute of Politics found that three out of four millennials believes human-caused climate change is real.

However, Johnson, who is the former governor of New Mexico, does not hold the same view.

The pro-Clinton ad shows footage from a 2011 appearance at the National Press Club during which Johnson took an unusually long-range view of climate change.

“In billions of years, the sun is going to actually grow and encompass the Earth, right? So global warming is in our future,” Johnson said. He went on to explain that it was not worth spending money now to address a problem that will have its worst consequences decades to centuries from the present.

In this Sept. 3, 2016 file photo, Libertarian presidential candidate Gary Johnson speaks during a campaign rally in Des Moines, Iowa. Image: Scott morgan/AP

"We can direct those moneys to other ways that would be much more beneficial to mankind," Johnson said, according to USA Today.

Johnson hasn't exactly changed his mind since 2011, despite even more scientific evidence showing that global warming is an urgent threat. On Wednesday, for example, the National Intelligence Council released a report finding that, by worsening heat waves, droughts and other extreme weather events, climate change is already helping to destabilize parts of the world.

"Is the climate changing? Probably so," Johnson's campaign website states. "Is man contributing to that change? Probably so. But the critical question is whether the politicians’ efforts to regulate, tax and manipulate the private sector are cost-effective –- or effective at all."

Clinton favors making major investments in renewable energy and cutting emissions of greenhouse gases. Her Republican opponent, Donald Trump, has promised to pull the U.S. out of the Paris Agreement on Climate Change and instead invest more money in domestic oil, gas and coal production.

“Climate change may very well be the biggest threat faced by millennials—and they know it," said NextGen Climate vice president Heather Hargreaves.

“Governor Johnson’s excuses for not combating climate change are absurd and nonsensical, showing that he is out of touch with a vast majority of young voters," she said.

NextGen Climate is working on college campuses to get young people to vote in battleground states such as North Carolina, New Hampshire and Ohio.