If there was any lingering confusion on how America's two major political parties differ over climate and energy policy, platforms released by the Republican and Democratic Parties during this month's national conventions made their often polar-opposite views exceedingly clear.
Republicans would dismantle the Environmental Protection Agency as it currently exists and abolish the Clean Power Plan, the centerpiece of the Obama administration's plan to rein in greenhouse gas emissions.
Democrats called for a price on carbon, implementation of the Clean Power Plan, which was stayed by the Supreme Court in February, as well as other regulatory measures to reduce greenhouse gases, and prioritization of renewable energy over natural gas.
While platforms are more outline of party beliefs than binding policy, they nonetheless offer a picture of the widening gulf between the increasingly conservative Republican Party and a Democratic Party that has adopted many of the progressive policies championed by Sen. Bernie Sanders.
The two parties' platforms take starkly different positions on education, immigration, health care and criminal justice, though their opposing worldviews are most plainly seen in their thinking on energy and climate.
The GOP platform states "coal is an abundant, clean, affordable, reliable domestic energy resource" and questions the scientific integrity of the United Nations' Intergovernmental Panel on Climate Change, the global authority on climate science. Democrats say climate change is an "urgent threat" and call for an 80 percent cut in carbon emissions.
Republicans would finish construction of the Keystone pipeline which would carry tar sands oil from Canada to Gulf Coast refineries and was rejected over climate concerns by the Obama administration. Democrats continue to oppose Keystone and call for a similar climate change litmus test for all future federal decisions so that they "contribute to solving, not significantly exacerbating climate change."
"It looks like two different worlds," said Daniel Fiorino, director of the American University School of Public Affairs' Center for Environmental Policy. "When I started studying political science a frequent observation was 'there is really not that much difference between the parties in the United States, it's tweedle dee and tweedle dum.' That's no longer the case and it's very apparent in their positions on environmental issues."
Another stark difference is support for the Paris climate accord, an international agreement adopted by 195 countries which aims to keep global temperature increases to "well below" 2 degrees Celsius, something the Republican Party platform flatly rejects.
"If we just unilaterally pulled out of this agreement that we played such a significant role in helping to create, this would make it very difficult for any president to exercise their foreign policy agenda," said Andrew Light, director of the Institute for Philosophy and Public Policy at George Mason University and a former climate official in the Obama administration. Democrats "take it as assumed that we would continue to work with other countries to do this because that is the only way of solving the problem."
What role party platforms play in shaping policy, however, is up for debate.
"It's an opportunity for a presidential campaign to satisfy some of the activists in the party by giving them the opportunity to shape the platform to their liking, but it does not necessary mean that the presidential candidate or other candidates for office hold all of the positions included in the platform," said David Hopkins, a political science professor at Boston College.
The Democratic Party platform, for example, includes a call to address the costs of carbon, while Clinton's campaign has made it clear that a carbon tax is not part of her climate plan.
Candidates may also go further than what is called for in their party's platform.
"If Trump wins I don't think the Republican platform would have any tethering effect on the way he governs," said David Victor, co-director of the Laboratory on International Law and Regulation at the University of California, San Diego. "I think he has a bunch of ideas about what to do that are actually bolder and more erratic than what's reflected in the platform."
A comprehensive analysis of Democratic and Republican Party platforms, however, shows that legislators closely adhere to those policy stances. Lee Payne, an associate professor at Stephen F. Austin State University analyzed every party platform from 1980 to 2004 and compared the policy positions to subsequent votes taken in the House and Senate. He found Democrats and Republicans voted in support of those positions 82 percent of the time.
"It does matter," Payne said. "People get what they vote for."
Glimpses of Trump's energy and climate agenda were on view last week at the Republican National Convention in Cleveland. "Every time we can't drill a well in America, terrorism is being funded," said Oklahoma oil and gas mogul Harold Hamm, who Trump is reportedly considering for his energy secretary.
While the Republican Party platform doesn't call into question the science of climate change, Trump called it a "hoax" in 2012.
North Dakota Rep. Kevin Cramer, a Trump energy adviser, jokingly spoke in favor of climate change at an industry-sponsored event during the RNC hosted by Politico. "We're for a warmer climate," Cramer said.