Gays are more beneficial to the environment/planet than heterosexuals are, assuming they have fewer/no children.
While I'm not gay, or against heterosexuals, this does help show people who have a magic invisible friend in the sky ("god") - who are the main ones against gays, that they are not better than gays, like their invisible friend says. In fact, they are a tad bit worse...if one cares for the environment/planet.
Straight people who practice family planning are, from this standpoint, likely equal to gays. But people who follow the teachings of their prophet (prophets seem to always want their followers to over-populate, so the prophet can become more powerful, in life and after his (it always a HE) death). The bible teaches this in Psalm 127:3-5. http://en.wikipedia.org/wiki/Quiverfull
Muslims follow this approach. Mormons do. Catholics, definitely! But a Secular Humanist approach is better for the planet, obviously.
The also believe the earth is going to END soon (and that's a good thing they think!) so no incentive to help save the planet, obviously.
Seven billion people and counting, so folks may want to start practicing voluntary family planning, if they care about our planet.