By: Alex Guillen Politico
October 1, 2012 04:29 AM EDT

Never fear, former White House climate adviser Carol Browner assured environmentalists Thursday night.  President Barack Obama has a big to-do list when it comes to their issues in a second term. Another reason to vote Romney

What exactly is on that list? Browner didn’t say in her pitch to a constituency that has had a sometimes fraught relationship with Obama. But she said environmentalists face a clear choice in November.

“We know there’s more work to do to defend the progress we’ve made. We’ve achieved a remarkable amount in 50 years,” Browner said on a campaign conference call, referring to Thursday’s 50th anniversary of the publication of Rachel Carson’s “Silent Spring.” Oh sure, likethe banning of the harmless DDT than has led to the death of tens of millions of Africans due to Malaria that had been controlled and the return of the bedbug infestation in the US that had been eradicated.

“But the decisions we make in the next four will have a lasting impact on generations to come,” she added.

Browner had plenty to say about the administration’s achievements: investing in clean energy, securing new fuel economy standards, proposing rules limiting emissions from new power plants.

Browner, a former Environmental Protection Agency administrator who is now at the Center for American Progress, also assured environmentally minded supporters that the president will remain faithful to their issues.

“I can tell you, having spent two years in the White House with the president, that this is not a fad. The president believes deeply in these issues,” she said. “At every turn he has looked at what are the tools available to him to really help build a clean-energy future for this country and has been committed throughout his first four years in office, and there’s no doubt in my mind this will be a big part of his to-do list and he will remain committed in the next four years.”

Browner also addressed the contrast between Obama and Mitt Romney when it comes to climate change, an issue that was largely absent from the campaign until Obama dedicated part of his convention night acceptance speech to stress that “climate change is not a hoax” and is “a threat to our children’s future.”

“The president has laid out a set of aggressive goals and is committed to [continuing] to build on the progress that he has made to date,” Browner said. “President Obama knows that it is critical to address the global issue of climate change and has made historic progress in working to reduce carbon pollution.”

Romney and his running mate Paul Ryan, she added, are wishy-washy at best when it comes to climate change science and have “pledged to prevent EPA from reducing carbon pollution that causes global warming.”

Obama has racked up endorsements from a host of environmental groups but has also had to overcome green voters’ unhappiness about failures like the death of cap-and-trade legislation in Congress and a White House-ordered delay in proposing new ozone standards. And though it wasn’t mentioned on the call, a central issue with environmental voters is the Keystone XL pipeline.

Greens were temporarily buoyed when Obama put off making a final decision on the pipeline until after the election, but they weren’t as happy that he has since embraced Keystone’s Southern portion, which will carry crude oil from Oklahoma to refineries in Texas. That inflamed worries that he will ultimately approve the full Keystone pipeline from Canada, allowing it to carry tar sands crude oil that environmentalists have labeled a threat to the Earth’s climate.

“Everybody, even the environmentalists, knows he’s going to approve it right after the election,” former Green Party presidential candidate Ralph Nader said last week in an interview with POLITICO.