A campaign adviser to Hillary Clinton says a key part of the Democratic Party's national platform on climate change is not supported by the presumptive Democratic nominee.

The latest version of the Democratic National Committee's platform was rolled out Saturday evening, and included support for a tax on greenhouse gas emissions from fossil fuels that many scientists blame for increasing the Earth's temperature.

But Clinton's campaign said the "carbon tax" measure reflects the view of some party members, and is not part of Clinton's own plan for addressing climate change, the Associated Press reported.

"Her plan is clearly articulated on her website," said Clinton's Energy Policy Adviser Trevor Houser. "It's not her plan."

The platform, to be voted on later this month at the party's convention in Philadelphia, reflects many of the policy provisions being pushed by presidential contender Bernie Sanders and his supporters. The Vermont Democrat has been successful in pushing Clinton out of her comfort zone and toward embracing more left-leaning policies.

"None of this would have happened in this forum without Bernie Sanders pushing this issue front and center over and over again," said environmentalist Bill McKibben, according to the AP. McKibben is co-founder of the the environmental group 350.org, which has been a key backer of Sanders.

The party platform said "carbon dioxide, methane and other greenhouse gases should be priced" to reflect the economic cost of the emissions on the environment. The platform also supports renewable fuels over natural gas power plants.

The platform falls short of endorsing a national ban on hydraulic fracturing, or fracking. The process, which is used to extract fossil fuels from rock deep underground, has helped the U.S. become a global leader in the production of oil and gas.

The platform supports placing more regulation on fracking, but said it should not occur where there is local opposition. Sanders, along with backers like McKibben, had been pushing both a carbon tax and a federal ban on fracking.