A new magazine for the environmentally and socially responsible bride and groom (hey, there's a magazine for everthing!) has introduced the first U.S. wedding carbon calculator.

"Weddings are a special way to announce a lifetime commitment," says Portovert Magazine editorial director Meghan Meyers. "But the truth is, even the most eco-savvy couple will create carbon emissions on their wedding day."

In partnership with NativeEnergy, Portovert has published its calculator at http://www.nativeenergy.com/Portovert today, Valentine's Day.

Visitors to the site can easily calculate the carbon emissions produced by the principal wedding-related carbon sources: guest travel, lodging, and venue power and heat.

Of course, there's an angle.

"For as little as $12 per ton of carbon offsets, brides and grooms can make a quick, easy investment in renewable energy by choosing one of three options: helping build new wind power projects, new family farm methane energy projects, or a combination of both," said Portovert in a statement.