Each time you take a flight or drive a car CO2 is released into the atmosphere. Although one could argue that any vacation that includes an airplane flight or use of a car can't be truly called "green," you can still contribute positively to the environment while on vacation. Choose forward-looking companies that embrace responsible development practices and help preserve destinations for the future. An increasing number of sustainable tourism initiatives can help you plan a family trip and leave as small a "footprint" as possible.

Responsible Travel (www.responsibletravel.com), run by a spokesperson for responsible tourism in the travel industry, contains a great source of sustainable travel ideas.

You can find eco-friendly travel tips, statistics, and touring companies and associations -- listed by destination under "Travel Choice" -- at the International Ecotoursm Society (TIES) website, www.ecotourism.org. Also check out Conservation International (www.conservation.org) which, with National Geographic Traveler, annually presents World Legacy Awards to those travel tour operators, businesses, organizations, and places that have made a significant contribution to sustainable tourism. Ecotravel.com is part online magazine and part ecodirectory that lets you search for touring companies in several categories (water-based, land-based, spiritually oriented, and so on).

In the U.K., Tourism Concern (www.tourismconcern.org.uk) works to reduce social and environmental problems connected to tourism and find ways of improving tourism so that local benefits are increased.

The Association of Independent Tour Operators (AITO) (www.aito.co.uk) is a group of interesting specialist operators leading the field in making holidays sustainable.

Whale-watching is popular from some parts of the Maine coast. For information about the whales you'll be glimpsing (and how to respect them), visit the Whale and Dolphin Conservation Society (www.wdcs.org). For info on traveling lightly in general, see Tread Lightly (www.treadlightly.org) online.

It's Easy Being Green

We can all help conserve fuel and energy when we travel. Here are a few simple ways you can help preserve your favorite destinations:

* Whenever possible, choose nonstop flights; they generally require less fuel than those that must stop and take-off again.

* If renting a car is necessary, ask the rental agent for the most fuel-efficient one available. Not only will you use less gas, you'll also save money at the tank.

* At hotels, request that your sheets and towels not be changed daily. You'll save water and energy by not washing them as often, and you'll prolong the life of the towels, too. (Many hotels already have programs like this in place.)

* Turn off the lights and air-conditioner or heater when you exit your hotel room.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.