From the July 2007 issue of Entrepreneur

As reducing greenhouse gases becomes a global priority, road warriors are considering the environmental consequences of business travel. It takes about 100 gallons of fuel to fly one person on a roundtrip transcontinental flight. So how can you mitigate the carbon dioxide produced in the process? By purchasing carbon offsets, which fund carbon-neutralizing activities such as tree planting (to absorb carbon dioxide) or the use of renewable energy.

TerraPass' "Puddle Jumper" costs $9.95, which balances out 2,500 pounds of carbon dioxide, or about 6,000 miles of flying. Or you can buy Green Tags, renewable energy certificates from the Bonneville Environmental Foundation. One Green Tag represents enough renewable energy to offset emissions from a typical home for a month. Bonneville's site has a calculator to determine appropriate offsets. Green Tags range in price from $20 to $56.

Several travel management firms (Carlson Wagonlit Travel, HRG) and online agencies (Expedia, Travelocity) now post carbon calculators. New York-based Ovation Travel has taken that idea a step further by teaming up with Carbonfund.org, which calculates a trip's environmental impact and bills your company for the appropriate offset.

If you're in the market for an offset, be sure to buy from an organization that details its projects and offers proof of their efficacy. Offsets that meet the Gold Standard, a best-practices designation, are also a safe bet.

How else can you reduce emissions? Consider something that can save time, money and the environment: videoconferencing.

Julie Moline is a freelance writer, editor and editorial consultant in New York City.