The environmental vegetarianism movement grows by the day, thanks to the slowly spreading fact that livestock production is to blame for more than half of the world’s greenhouse-gas emissions. If people resolved to cut back on meat and dairy in 2010, the world would be a much cleaner place.

Yearly Impact:If you refrain from eating meat just one day a week, you'll save as many emissions as you would driving 1,000 fewer miles this year.

We hear people preach about recycling all the time. But did you know that composting may be as important? As food and other organic waste decomposes anaerobically in the landfill, it releases methane, a greenhouse gas that's more than 20 times as potent as carbon dioxide. Because composting is an aerobic process, it only produces carbon dioxide and not methane. Not sure how to get started? Click here and here to find out.

Yearly Impact:If the average family composted regularly, that household would prevent about 30 pounds of methane emissions per year, the equivalent of around 620 pounds of carbon dioxide (the same as what a small diesel car driving 1,200 miles would emit).

Heed President Obama's call to service by signing up to help an organization that works to improve the world. We know we’re biased, but we think the Sierra Club, which fights to preserve and protect the environment, is an excellent candidate for your time. Find your local chapter to learn how to get involved.