Question: What Are the Best Global Warming NGOs?

Caterina Fake asked WorldChanging: "So, I am really worried about global warming and I want to know which non-profit would be best for me to contribute funds to address the issue (and I figured you'd know)." Alex Steffen replies: "in North America, it seems to be the local and regional groups which are both doing the most inspiring work and most need the funds. For instance, the Northwest's leading climate NGO, Climate Solutions, is doing great work not only on educating the public but on getting nuts-and-bolts reforms to favor wind farms, biofuels and smart grids. Also, it looks like these local/regional groups are increasingly cohering into a networked movement to create national change in the U.S. and Canada." But he then redirects the question to WorldChanging's readers and asks for recommendations. We would like to do the same and ask you which are your favorite Global Warming non-governmental organizations (NGO)? You can answer in the comments here, or on ::WorldChanging.