Worried that their party is vulnerable on environmental issues, some Republicans in recent months have been trying to foster a gentler, greener image. An influential memorandum penned last fall by GOP strategist Frank Luntz advises Republicans to sprinkle terms like “balance” and “common sense” into their environmental speeches, and to stick to the word “conservationist,” which he says sounds more “moderate and reasoned” than “environmentalist.” On the topic of climate change, Luntz tells GOP politicians to stress that there’s a lack of scientific certainty on the issue (never mind that there isn’t). He also suggests that they portray themselves as enthusiastic backers of national parks, saying it’s important to show that “Republicans can be for something positive in the environment.” Kim Haddow, a Sierra Club consultant, says Republicans are no longer playing defense on the environment: “The ball is back in our court, and we need to spend time and energy educating voters.”