Lindsey Graham announced Monday that he’s joining almost two dozen other Republicans to run for president. Unlike his opponents—who change their position almost-hourly (Jeb Bush) or accuse the press of trying to politicize the problem (Senator Ted Cruz)—Graham accepts climate change is real and manmade. 

In March, Graham admitted his party needs to do some “soul searching” on climate change. “What is the environmental platform of the Republican Party?” he asked. “I'd like to come up with one. I'd like to have a debate within the party. Can you say that climate change is a scientifically sound phenomenon, but can you reject the idea you have to destroy the economy to solve the problem is sort of where I'll be taking this debate.” 

Environmentalists have high hopes for the South Carolina senator. His entry “would be a breath of fresh air,” said Suzanne Henkels, a spokesperson for Tom Steyer's NextGen Climate. Slate’s Eric Holthaus wrote a glowing story on Graham’s commitment in March, saying “Graham has the ability to bridge the divide between the right and the left by motivating the GOP to consider practical solutions to climate change that can improve the welfare of the entire world."

Graham, who's crafted moderate bills on cap-and-trade and immigration reform, might be best known as a foreign policy hawk and an opponent of the Obama administration's Middle East strategy. But his hawkishness is precisely what makes his pitch on climate change that much more effective to a different kind of audience. He might describe curbing greenhouse gas emissions in terms of national security, allowing him to distance himself from President Barack Obama without denying scientific reality. “The logical thing​ to do is to jump on to Obama's position on climate change as a national security issue and out-muscle Obama's actions,” e-mailed R.L. Miller, founder of the campaign group Climate Hawks Vote that supports climate-friendly candidates. 

Obama noted in a speech in May how sea level rise threatens military bases and climate extremes can destabilize civilization. Many Republicans ridiculed this, but Graham’s actually been saying this for years. 

”I really do believe that our energy dependence, that as much as we rely on foreign oil as a national security nightmare, I believe that climate change is real and it's going to affect the food supply over time, and it's going to make the world even a much more dangerous place,” he said in 2009. "A bunch of generals are saying it. So I think there's a lot of national security reasons that you'd want to control greenhouse gases. A lot of national security reasons you'd want to get more independent when it comes to finding your own energy."

In March he said, “I don’t know if it’s an immediate national security threat, but I think the effects of climate change can destabilize the world. In that regard, it is a national security threat.”

Graham is a long shot for the presidency—he's at the back of the pack in polling—and climate advocates realize he won't singlehandedly shift his party's position on global warming. Though a long-time senator and a regular on the Sunday show programming circuit, many Republicans nationwide either don’t know who he is, or don’t like him.

Nor is Graham as reliable an environmental ally as most Democrats are. He backs a number of policies that are detrimental to the environment, including development of the Canadian oil sands and drilling in the Arctic National Wildlife Refuge. He’s a big believer in nuclear energy as a solution to carbon pollution. While he played a key role crafting a 2009 cap-and-trade proposal in the Senate, he later walked away from it. And once, in true Republican fashion, he questioned the scientific founding for climate change.

But compared to most of the Republican candidates, he looks downright progressive.