The livestock sector is responsible for 18% of greenhouse gas emissions worldwide, while all the cars, lorries, ships and planes added together do not account for more than 13% of greenhouse gas emissions.

It's so easy to commit to one day a week without meat, not only will it be beneficial to the environment, but it can have a positive impact on your health as well.  If you are a die hard meat lover, try using a meat substitute like Morning Star Crumbles, they work great with tacos, chili, or spaghetti sauce.

for more on this subject:  http://hubpages.com/hub/The-carbon-footprint-of-meat-consumption