When it comes to climate change the United States often seems to be going solo. It's the only nation to pull out of the Paris Climate Agreement. US greenhouse gas emissions are rising. And the government is rolling back environmental regulations. Climate change is a polarizing issue in the United States.

But as CGTN's Karina Huber explains, it wasn't always this way.

When climate activist Greta Thunberg appeared on the Daily Show with Trevor Noah, she expressed bewilderment at how climate change is viewed in the U.S.

"Here it feels like it is being discussed as something you believe in or not believe in. Where I come from it's more like it's a fact," said Greta Thunberg, a climate activist.

Polls indicate that a majority of Americans now believe what scientists have said for years that human-caused climate change is real and a growing number see it as a threat. But, the issue is still politically polarized in the U.S.

A growing number of Americans describe climate change as a crisis, and two-thirds say President Trump is doing too little to tackle the problem.

"The U.S. is almost unique among countries of the world in terms of at least the government questioning whether it's real. My view is that the skepticism that exists in the United States is largely collateral damage from a larger phenomenon which is political polarization," said Robert Stavins a professor of environmental economics at Harvard University.

Andrew Winston, the author of "The Big Pivot" says environmental issues haven't always been politically divisive.

"It's become well if you care about the environment, you must be a Democrat. If you don't, you're a Republican. And what makes it more strange, is that the biggest environmental laws in the world, were started in the U.S. in the early 70s and were signed by Richard Nixon and were led by Republicans," said Andrew Winston of Winston Eco-Strategies.

Winston believes the answer lies in part in the success of the Academy Award-winning documentary "An Inconvenient Truth."

The film follows former Democratic Vice Presidential Candidate Al Gore on his campaign to educate people about climate change. In the process, Gore, a Democrat, became the face of the issue.

"I think if Al Gore had not done what he did, which in many ways was obviously helpful in terms of raising global awareness, which is why he received the Nobel Prize, I think the political polarization on this issue might have been less than what it has been," said Robert Stavins a professor environmental economics at Harvard University.

Winston says there was also a concerted effort by the fossil fuel industry to downplay the science around climate change and brand the use of fossil fuels as American.

And so it got wrapped up in this set of issues that are really something the Republican party, in particular, have gravitated to and it's part of this package of ideas about freedom of the individual, free markets and that being able to burn whatever you want, use whatever energy you want is part of that," said Andrew Winston of Winston Eco-Strategies.

The fossil fuel industry now acknowledges climate change is real and warrants action, but the polarization in the U.S. remains severe and little is being done to curtail emissions.

The Trump administration continues to roll back Obama-era environmental regulations and the U.S. carbon dioxide emissions are rising climbing an estimated 3.4% last year. This, at a time when scientists say the world needs to aggressively cut emissions to avoid the worst outcomes of climate change.