Environment

CarbonCounter.info/calculators.html -- Carbon Counter calculators
EarthDay.net -- Earth Day Network
EDF.org -- Environmental Defense Fund
Freecycle.org -- Freecycle network
Greenpeace.org
Mass.gov/DCR -- Massachusetts Department of Conservation & Recreation
PewClimate.org -- Pew Center on Global Climate Change
Science.gov
Scorecard.org -- Pollution information
SierraClub.org
TheGreenGuide.com -- National Geographic environmental site
WebElements.com -- Periodic Table of the Elements
World.org -- World Environmental Organization
WWF.org -- World Wildlife Fund