Science Daily Sustainability News
http://www.sciencedaily.com/news/earth_climate/sustainability/
United Nation Environment Program
http://www.unep.org/
National Geographic Environment News
http://news.nationalgeographic.com/news/environment.html
New Scientist
http://www.newscientist.com/section/environment
Yahoo Global Warming News
http://news.yahoo.com/topics/global-warming
Popular Science
http://www.popsci.com/
Pembina Institute
http://climate.pembina.org/