Koch Industries, generally viewed as Lucifer by environmentalists, surprised people at a recent Wall Street Journal forum when the company’s director of environment, health and safety, Sheryl Corrigan, said that climate change is real and people have something to do with it.

“I think Charles has said the climate is changing,” Corrigan said, referring to Charles Koch. “So the climate is changing. I think he’s also said, and we believe, that humans have a part in that.”

But then she added, “what the real question is…what are we going to do about it? What is the right answer?”

This week, Sierra Club executive director Michael Brune, who has no shortage of ideas about what to do about it, decided to write an open letter to Charles Koch making a few suggestions for starters.

“I wanted to write to welcome you into the not-very-exclusive club that includes the strong majority of Americans, 99+ percent of scientists, nearly all Democratic candidates and a growing number of conservative Republicans,” he wrote. “We’re happy to have you!”

Brune said his first suggestion was to speak up. “Your voice is an important one and I hope you’ll speak up if your opinion has truly changed.”

Next, he said “now that your position on climate change may be shifting, we hope that you’ll join the push toward the clean energy economy and invest in the clean energy sources that increasingly are powering America and the world.” Brune noted that these energy sources are “becoming more affordable and more accessible each day.”

Third, Brune said it was time for the Kochs to stop funding “organizations and political candidates who either deny climate science or oppose nearly every policy that would advance climate solutions.” He singled out the American Legislative Exchange Council, which has been campaigning to roll back renewable incentives in states.

Whether Brune gets a reply remains to be seen. Some environmental activists believe Corrigan’s comments are part of an effort by the Kochs to reach out to journalists and others, to be as a New Yorker article by Jane Mayer branded it, the New Koch, new packaging for the same old beliefs and interests. Koch Industries owns oil refineries, large lease holdings in the oil sands region of Alberta, and other energy investments.

But if Charles Koch, a graduate of the Massachusetts Institute of Technology, has had a change of heart, it would be worth exploring, Brune said in an interview.

“We’re looking at this positively,” he said. “Once you have an institution that is one of the largest players in politics aggressively promoting climate denialism suddenly change its stance and say that climate change is real and humans have a role in solving it, that is a huge opportunity. It potentially represents a sea change in climate politics.”

Brune, noting that the brothers Charles and David Koch are expected to spend hundreds of millions of dollars on political campaigns this year, said that “there are few things that get our members more worked up than Koch brothers messing with our elections, and messing with our climate.”

But he said that “eventually the Republican Party si going to have to come around on climate change.” And, he added, “in a cynical way, that can’t happen until two rich executives from Wichita, Kans. signal that it’s okay.”

Even if the Koch brothers were to recognize climate change, coming to any sort of an agreement between the likes of the Sierra Club and the libertarian, anti-regulation, anti-tax Kochs seems remote.

“When we have subsidies and mandates it can pervert that situation and make it that much harder to bring ideas forward,” Corrigan said at the Wall Street Journal event. She said “let those technologies compete and the market will sort it out.”

Brune said he would “love it” if there were “a competition in the marketplace of ideas” about the best way to phase in clean energy, increase prosperity and decrease emissions. He said maybe one of the sessions at the Kochs’ reported secret strategy sessions could be devoted to the topic. “I’d be happy to lead a workshop,” he said.

Regardless of which party you support, there's almost no question that the Koch brothers have made money off of you. (Jeff Simon, Daron Taylor/The Washington Post)

Read more at Energy & Environment:

For more, you can sign up for our weekly newsletter here, and follow us on Twitter here.