First and foremost, if you have not already done so, please do join the Climate Corps:

It’s free to join the Climate Corps and we will never share your contact information with anyone, under any circumstances, ever, period. What your joining will do is bind you with a growing number of people interested in changing the future of the planet earth for the better. You will receive an occasional email from us sometimes to let you know of new material or functionality of the site, sometimes to remind you to share us with others, and sometimes to ask you to take some timely action towards the mitigation of global warming or other sustainability goal.

By joining the Climate Corps you become part of a cohesive force for a sustainable future.

That said (and hopefully done), there are lots of other wonderful organizations for you to join to help move us towards sustainability and away from global warming. Here are a just a few:

• Natural Resource Defense Council’s Action Network
• Sierra Club
• Environmental Defense