With over five million supporters and a presence in over 100 countries worldwide, the World Wildlife Fund (aka the World Wide Fund for Nature) is, perhaps, one of the best-known advocacy groups on the planet. Their platform is the preservation of wildlife and reduction of human impact on the environment–and they’ve made a serious impact Since 1995, the WWF has invested over $1 billion in conservation initiatives. Today, the WWF’s focus is on restoring 36 different species, such as elephants, tunas, and whales, among others, and reducing the ecological footprint in six key areas, like carbon emissions and fishing.