Green shirt? Check. Green flashing shamrock pin? Check. Green diet? Check.

If you want to be really green this St. Patrick's Day, consider test-driving a planet-healthy vegan diet. According to Environmental Defense, if every American skipped just one meal of chicken per week and substituted vegetarian foods instead, the carbon-dioxide savings would be the same as taking more than half a million cars off U.S. roads.

It takes more than 2,400 gallons of water to produce 1 pound of meat, while growing 1 pound of wheat only requires 25 gallons. You save more water by not eating a pound of meat than you do by not showering for six months. (And people will still be willing to sit beside you.)

Animals raised for food have to eat as many as 16 pounds of grain to produce 1 pound of edible flesh. If that grain were fed to people instead, we could easily feed everyone on the planet, ending world hunger.

Irish model Rosanna Davison poses in front of the Spire of Dublin as part of a PETA U.K. demonstration

Whether you're Irish or not, today is your lucky day. Request your free vegetarian/vegan starter kit from PETA. You'll avoid being pinched by your conscience, and your friends will be green with envy over your new figure.

Written by Michelle Sherrow

According to the British music magazine NME, Irish sperm donors are in short supply and one enterprising sperm bank has come up with an incentive scheme in time for St. Patrick’s Day (donations in exchange for contest tickets).

Always ready to help (and mindful of how good fruit and veggies prove in fertility studies), PETA is offering a special St. Patrick’s Day T-shirt to help remind anyone with a touch of the Blarney that drinking milk can lower their sperm count. I defy anyone to choose a pint of milk over a pint of Guinness after looking at this particular masterpiece.

Anyway, good luck lads, and happy, um, donating.