03/18/2010 05:12 am ET Updated May 25, 2011

Air Travel Made Greener: 4 Tips

The airlines seem to be lagging when it comes to reducing their environmental wingspans. And plane flights are hard on the planet. Though air travel is unavoidable at times, there are a few things responsible travelers can do to make flights greener.

1. Decline the Napkin. When your flight attendant hands you a napkin with your drink, politely decline it, explaining, if you like, that you'd prefer to save the paper. Even better, write to the airlines to urge them to train flight attendants to offer napkins rather than passing them out by rote, which could save untold numbers of trees, plus some corporate cash. To find airline contact information, go to this link and click on "Airline Consumer Contacts."

2. Ensure Recycling. Before giving your cup or can to the flight attendant collecting trash, ask if the plastic or aluminum will be recycled. If the answer is no (it usually is; see some remarkable stats here), stash yours in your carry-on and dispose of it in the first recycling bin you see after you deplane. Later, call or write to the airline's customer service department to urge it to implement a recycling program.

3. Pack Light. The equation is simple: Heavier luggage burns more fuel. So if everyone leaves a little more at home, we'll vastly reduce emissions. (Incidentally, this is a good reason to lose body weight too.) And remember to get those liquids, gels, and aerosols out of your carry-on if they weigh more than 3 ounces. Otherwise, they'll end up in the landfill before their time.

4. Offset. This is the obvious tip for greening a plane flight. It's still controversial -- some view carbon offsetting as penance for an irrevocable sin. But the Sierra Club thinks it"s better than nothing. If you're going to fly, what's the harm in also funding renewable-energy projects and reforestation efforts?

Tell us: How do you go green when you fly?