"California has wonderful, natural places -- Yosemite, the Sierras," Sierra Club spokeswoman Kristina Johnson said. "There's a lot of opportunity for people to just get out and enjoy nature. . . . It's really hard to want to destroy a forest when you've spent some time hiking around in it."
The Sierra Club and environmental organizations offer volunteer vacations or day hikes doing things like trail building, picking up trash, removing invasive plant species or conducting archaeological surveys. Zoos, aquariums and national and regional parks offer minimally invasive programs that educate tourists and teach them how to carry environmental practices into daily life. Many aquariums, for instance, give visitors take-home cards on overfishing and suggest types of fish to avoid at restaurants and the grocery store.
If your activities take you to more commercial operations, be careful about which businesses you patronize, green travel experts say. Some activities, like whale watching, may sound ecologically friendly, but is the boat crew being mindful of the animals' mating and migration habits? Does the boat interfere with the habitat by getting too close?
"Do your homework; do your due diligence," said Brian Mullis, a spokesman for the nonprofit Sustainable Travel International. "Ensure that your footprint is as light as possible and that your positive impacts are maximized."
Travelers shouldn't be afraid to ask about a company's environmental practices, Mullis said. Doing so helps send the message that customers care about responsible practices, he explained.
Sustainable Travel and Green Globe have the only two global, sustainable tourism certification programs, but Mullis said there were more than 70 other companies and agencies offering certification programs to businesses. The problem, he said, is that some can be purchased, leading to "greenwashing" of the industry.
Industry efforts are underway to develop baseline standards and an agency that would accredit certification programs, Mullis said.
In some areas -- including places as varied as developing countries and the Rocky Mountains -- tourism can boost the economy so it becomes less dependent on mining, drilling, logging and other resource extraction.
Mullis suggested that travelers skip the all-inclusive megaresorts and consider staying at a locally owned hotel, hiring a local guide, eating at neighborhood restaurants and buying souvenirs from local artisans and vendors. Funds you spend with local artists and performers also encourage the preservation of cultural heritage.
In Santa Barbara, the visitors bureau has put together a guide that includes categories such as green activities and green restaurants. Among the suggestions are a visit to a botanical garden, the Los Padres National Forest or the Gypsy Canyon Winery -- where grapes are grown using biodynamic methods, wine is bottled in recycled glass and labels are handwritten on recycled paper.
Pack it out
Conservation International, working with the United Nations Environment Programme, has developed "good practice" guides for tour operators in rain forests and mountain regions.
The guides are geared toward businesses but include tips for visitors. For example, even activities that seem low impact -- such as hiking and camping -- can cause problems if tourists aren't sensitive, Conservation International spokeswoman Katherine Kelly said.
According to the guide, hikers ought to use clean equipment and shoes or boots to keep chemicals from entering waterways and the local ecosystem. Camps should be erected at least 100 feet from streams and other water sources. Pack out everything you pack in, and don't disrupt wildlife or hike off the beaten path in parks.
"Try to make a minimal impact on the land or the place you're visiting," the Sierra Club's Johnson said.
Conservation International's guide advises that if a tour requires transportation, horses and mules are better than motorized alternatives. If vehicles must be used, they should be two-wheel drive and avoid rough driving to minimize their effect on vegetation.
All-terrain vehicles, in particular, can be very damaging to wildlife areas, Johnson said.