We donate to:

Coral Reef Alliance http://www.coral.org
Defenders of Wildlife  http://www.defenders.org
World Wildlife Fund  http://www.worldwildlife.org
Nature Conservancy   http://www.nature.org
Plant a Billion Trees http://www.plantabillion.org (Nature Conservancy)
Rainforest Action Network http://www.ran.org
Ocean Conservancy  http://www.oceanconservancy.org
Center for Biological Diversity  http://www.biologicaldiversity.org
Union of Concerned Scientists http://www.uscusa.org
League of Conservation Voters  http://www.lcv.org/
Friends of the Earth http://www.foe.org