This is one of the most inspiring essays I've read in quite some time.

Paul Hawken writes:

   I have given nearly one thousand talks about the environment in the past fifteen years, and after every speech a smaller crowd gathered to talk, ask questions, and exchange business cards. The people offering their cards were working on the most salient issues of our day: climate change, poverty, deforestation, peace, water, hunger, conservation, human rights, and more. They were from the nonprofit and nongovernmental world, also known as civil society. They looked after rivers and bays, educated consumers about sustainable agriculture, retrofitted houses with solar panels, lobbied state legislatures about pollution, fought against corporate-weighted trade policies, worked to green inner cities, or taught children about the environment. Quite simply, they were trying to safeguard nature and ensure justice.

And here's an interview with the author (he's now written a book on the subject).