Antipixel posted a link to The Voluntary Human Extinction Movement:

VHEMT (pronounced vehement) is a movement not an organization. It's a movement advanced by people who care about life on planet Earth. We're not just a bunch of misanthropes and anti-social, Malthusian misfits, taking morbid delight whenever disaster strikes humans. Nothing could be farther from the truth. Voluntary human extinction is the humanitarian alternative to human disasters.