Since eco-friendliness has become trendy, I really don't think it's terribly fair to use a self-reported survey to make a generalization like this. Of course soccer-mommy with her hybrid minivan is gonna report that she is an "eco-warrior", whatever that means.
But I know plenty of gun owners who self-identify as staunch 2a supporters who think the NRA is "too extreme" and that handguns are only for killing people and therefore no one but cops and soldiers should have them.
Because of some of my so-called lifestyle choices, I run into a *lot* of very eco-conscious people. Many of these folks voluntarily abstain from car ownership or a shared car between multiple families, have elaborate composting systems, measure the amount of garbage they generate in constant attempts to reduce it (and they don't generate much), don't use disposable items (oiled cloth for food storage, or glass jars, washable diapers, "paper" towels, feminine products and toilet "paper"), view recycling as a last resort, preferring to not use an item to begin with. They grow their own vegetables, and what they can't grow they buy locally. They tend to buy clothing that they or other families like them make. I do very few of those things, and don't think of myself as an environmentalist at all, but I cannot deny that these folks are zealots who take their self-proclaimed mission very seriously and don't take anything for granted. Mostly their vacations are backpacking or camping close to home. Although they are mostly anti-gun, they are certainly not sheeple.
And yeah, they really, really don't appreciate that buying a brand-new hybrid car every year is now considered "environmentalism". Surveys like this apply to real environmentalists about as much as a survey of "handguns are evil, but don't take my hunting rifle" would apply to the average THR-er. Most so-called environmentalists are indeed hypocrites, but don't tar all of them with that brush.