I don't understand you eco-nuts," an Alaska fur trapper once said to a young man opposed to trapping. "How the hell can you love a beaver and hate a dam?" And the environmentalist had to admit the grizzled codger was right. For all the ecological damage inflicted by the construction of colossal hydroelectric dams, there's nothing unnatural in the act of humans making them. If people are part of nature, then there's really nothing we can do that is unnatural.

It's not our failure as a species that threatens our future so much as our phenomenal success.

More people have arisen in the last 100 years than during the entire time since our ancestors began to walk upright. Our numbers are expected to double again in the first half of this century. Until humanity stabilizes its population, and achieves the even greater challenge of reducing our numbers to sustainable levels, we need to adjust our collective behaviour.

Sadly, the largest expenditures in the world today are not being applied to a green solution — the development of alternative energy sources, sustainable food production, and a more equitable distribution of the world's wealth — but rather to the global weapons industry. The second-largest industry in the world, interestingly enough, is tourism. Eco-tourism is the most rapidly growing sector in that industry, and many see it holding real promise for humanity's future.

It's hard to imagine a stronger potential force for bringing about cross-cultural respect and understanding, a better way to achieve environmental awareness, than the opportunity to travel to distant lands, meet different peoples and experience the great diversity of natural environments. Yet the very act of boarding a jet to do so pretty well negates the benefits, according to some critics, who now equate eco-tourism with eco-terrorism.

Whether the ecological footprint of a tourist lands light or heavy depends on such factors as the mode of travel, the volume and frequency of visitors, and the level of awareness of the tourism operator. Some sea-canoe companies, for example, pride themselves in their environmental ethics. With highly trained staff, restricted client numbers, and firmly enforced eco-guidelines, they're able to pass through southern Thailand's mangroves and karst islands like fish through water or birds through air, leaving no trace of their passage. Other operators, less aware or less scrupulous, maximize profits by cramming as many people as possible into a site each day. They show little or no regard for group safety or environmental impact. Some companies who bill their business as eco-tourism have no idea what the expression "eco" even means.

Never having benefited from ecology lessons at school, and coping with a foreign language, Thai people may be forgiven for thinking that "eco" is an abbreviation for "economic". A recent survey of southern Thailand's eco-tour companies found the majority of them defining eco-tourism as "not too expensive tourism". One wanna-be green company was actually advertising "econo tours."

For all its failures to date, the greedy rush to climb aboard the environmental bandwagon by many less than knowledgeable operators, the potential for real awareness and real eco-tourism sits at Thailand's doorstep. So does the potential for ecological disaster. More than 10 million foreign visitors now descend on the Kingdom annually, and the government hopes to double that number. A national strategy of promoting tourist quantity over quality of experience is reflected by official awards to those operators who bring in the greatest number of visitors. For all its economic sense, such a strategy is a recipe for social and environmental trouble.

On an annual basis, foreign tourists already outnumber Phuket residents ten to one. Few countries in the world could absorb this volume and still retain "the land of smiles" as a motto. And ecological consequences of mass tourism can be more serious than the social.

Government planners are often faulted for corruption and gross negligence in not establishing adequate infrastructure and regulations to protect the country's world-class sites. The simple truth is that the most honest and dedicated planners in the world couldn't keep pace with the number of new arrivals. For eco-tourism to have any meaning beyond trendy advertising hype, Thailand needs to do what the whole world needs to do with its population problem and global economy — recognize the limits to growth. But such a paradigm change is unlikely to happen soon. As long as visitor numbers are contributing to the problem, the onus will be on us as tourists to minimize our own impact.

There are a lot of ways in which we can do this. A good place to start: patronize establishments that pay more than lip service to their eco-tourism claims. Challenge them to explain their policies and hold them accountable. Ask them to "walk their talk" once you book their tour. If you're unimpressed, tell them so, and suggest what they need to do things differently before you'd take their tour again or recommend it to others. Relatively few Thais have enjoyed the benefits of environmental education, so tourists can often assist guides. It's important to do this in a friendly, off-to-the-side manner. No one in a leadership role wants to be corrected in public and, in Asia, saving face is of utmost importance.

Many of us grew up watching the legendary Jacques Cousteau hitching rides on sea turtles or poking pufferfish to watch them inflate like clownish balloons. But Cousteau, the inventor of scuba, was one of a very few doing these things. Today, millions of divers want to do the same. Female sea turtles have been found so exhausted from hauling scuba divers around all day, for example, that they have no strength left to crawl up the beach to deposit their eggs. Having our behaviour catch up with our numbers is one of the age's greatest environmental challenges. Our children can't collect butterflies or seashells with the same innocent abandon that we once did. Not with the world's population, already exerting unsustainable pressures, doubling within a single generation.

Beaches become so stripped of mollusc shells by tourists and commercial collectors that hermit crabs can now be seen sorting through plastic beach litter in search of homes. Thai law forbids the collection and sale of corals and shells from all Thai waters, but that doesn't stop the importing and sale of huge quantities of these species from neighbouring countries. Where national laws reflect no global consciousness, then tourists need to show their own awareness by refusing to purchase these objects.

Tourism, of course, does not always negatively influence an environment. On the contrary, it can bring real and immediate benefits. One example can be found at Khao Sok's Cheow Lan Reservoir, where a growing body of evidence suggests that the increasing numbers of tourists on wildlife-watching "dawn safaris" and "night

safaris" present the greatest deterrents to poachers. Prime-time wildlife viewing is also the prime time for hunting, and the former, fortunately, pretty well excludes the possibility of the latter.

Another area where tourism clearly benefits nature is seen in the number of parks and preserves being set aside for wildlife. Few impoverished countries would see such designations as a national priority, were it not for the prospect of attracting foreign revenues from tourism. Entrance fees for visitors can also support conservation programmes that could not otherwise find funding.

The eco-tourism industry, like any other business, must never let itself get complacent, basking in the light of much-publicized success stories, and believing it can do no wrong. It must constantly re-evaluate its impacts in any given area, making sure that the commercial bottom line isn't compromising its ethics. Krabi's Khao Nor Chuchi forest reserve epitomizes the complex dilemmas this new industry faces.

When ornithologists discovered a breeding population of the Gurney's pitta here — a bird long thought to be extinct — it mobilized bird lovers world-wide. Southern Thailand's last lowland forest was saved in the global effort to protect this most endangered bird species. Eco-tourism was promoted to the local villagers as an alternate source of wealth that could supplement, if not replace, their historic dependency on clearing land for palm oil and rubber tree plantations.

Eco-tourism companies started popping up overnight in Krabi Town and Ao Nang to capitalize on the site, and the Tourism Authority of Thailand (TAT) encouraged high-volume visitor flow with the construction of an elevated walkway to a popular swimming hole in the very heart of the reserve. No one will ever know for certain if the sudden flow of visitors pushed the last 15 breeding pairs of Gurney's pitta to more remote areas of the reserve, but ornithologists now report only sightings far from the popular tourism area. The saddest irony is the fact that the locals, who never did realize any significant eco-tourism benefits, went back to their traditional clearing of forests. They are now illegally clearing the very habitat the Gurney's pitta needs in order to survive. Krabi has a new eco-tourism destination it markets to the world, but the very reason for protecting it may have become lost in the process of publicizing it.

The world has yet to come up with a universally accepted definition of what constitutes eco-tourism. Current usage ranges from absolutely no idea, to any type of outdoor soft adventure, to a comprehensive environmental education experience. The best models for the concept offer eco-lodges run on wind or solar power, serve organically grown (often vegetarian) meals, compost their garbage, recycle their water, build with native materials only, never use herbicides, pesticides or insecticides, and minimize the use of fossil fuel consumption by encouraging such activities as hiking, cycling, canoeing and sailing.

garbage, recycle their water, build with native materials only, never use herbicides, pesticides or insecticides, and minimize the use of fossil fuel consumption by encouraging such activities as hiking, cycling, canoeing and sailing.

True eco-tourism means respecting and supporting local peoples and their cultures, expanding ones awareness of environmental concerns, and engaging in stewardship programmes that help to protect wildlife habitat and restore areas that have been degraded. Above all, it means returning from an experience changed for the better — a healthier, more-aware and responsible global citizen.

Cynics are quick to point out that the best way for a person to minimize their impact on the earth is to stay at home. While this may hold true for traditional subsistence societies, it hardly applies to the world's wealthy countries, where daily life gobbles up an inordinate amount of the world's resources. Even factoring in the air pollution from an international flight, a person from such a place could reduce their ecological footprint by spending a week or two resting in a beach bungalow, eating local foods and reading a book instead of driving to work.

Our growing numbers will continue to fuel the debate whether eco-tourism in the end becomes eco-terrorism. For now, we still have choices in our individual and collective behaviour. Nature is resilient, and humans incredibly adaptable, so we needn't buy too quickly into doomsday scenarios. For all of its glaring faults, and simple shortcomings, the concepts eco-tourism puts forward are not pie-in-the-sky ideals. They may well be part of humanity's best blueprint for survival.