Although they may be less adorable than penguins and less gripping than melting ice caps, resort owners and tour operators will be directly and strongly affected by climate change. Without doubt, few livelihoods are more dependent on the weather, other than farmers'.

Last month, organizers of a U.N. conference in Davos, Switzerland, sought to hammer that point home to officials and tour operators from nearly 100 countries.

''The entire tourism product will be affected,'' said Geoffrey Lipman, assistant-secretary general of the U.N. World Tourism Organization, ''Every destination has a climate-related component.''

Lipman said if the climate was going to change, ''which we know it will, we'd all better adapt.''

A changing climate is the only certainty, he said. What kind of change and how it will affect a nation's tourism industry will depend on where you are and what you offer. Climate change in some places may actually provide opportunities.

''Some people are going to find that they had tourism before and don't now,'' Lipman said. ''In the Canadian Rockies, it may be the reverse.''

''The tourism industry must adapt rapidly,'' concluded the final report of the U.N. conference.

Imagine a ski resort whose chairlifts are in the lower reaches of mountains without decent snow. Or a scuba club whose reefs succumbed to warmer and stormier seas. Or a golfing hotel in a district where water shortages made it impossible to keep fairways green.

All are real possibilities, industry experts say, and in fact, early effects are already being felt. In the developed world, tour operators do not generally face a crisis, though future profits will depend on successfully adjusting.

But along the equator, where keeping the tourism industry afloat can have a significant economic effect, the stakes - and the risks - are greater.

In much of Africa, for instance, tourism is the major source of income and often the only source of foreign currency.

Yet the costs are heavy. With the industry's reliance on cars and buses, air-conditioning and especially air travel, tourism is a major source of global-warming gasses. The tourism trade accounts for about 5 percent of the world's carbon dioxide emissions, the Davos conference concluded. And poor countries normally do not have the money to make changes to improve the environment.

''It's nice to talk about reducing air travel, but many nation-states depend on it,'' Lipman said. ''Think about what happens to New Zealand and Australia. More important, what happens to poor countries - the Maldives, Seychelles and Africa - who need it because it is the only way to get tourists in.''

Recognizing that tourism and climate change are intertwined, Fiji combined its environment and tourism ministries this summer.

''Tourism is the vehicle for poverty alleviation in Fiji - that's how important it has become,'' said Banuve Kaumaitotoya, permanent secretary of Fiji's ministry of tourism and environment, who attended the conference. ''Without it, our economy would collapse.''

Already, more frequent storms in Fiji, which some scientists say are caused by global warming, are eroding mountains and driving earth and fresh water into the sea. That threatens to erode pristine beaches and endangers saltwater coral reefs.

Fijian planners are trying to anticipate the course of such change and set new standards, such as guidelines for how far above the water bungalows should be built to be safe if the sea level rises.

''At the moment, the effect is subtle, but we don't want our reefs - our island - to disappear,'' said Kaumaitotoya.

Across the world, at the Whistler Blackcomb Ski Resort in Canada, glaciers are receding and good snow is found higher up the mountain than 10 years ago.

''We've been building lifts higher, in more snow-reliant zones to give us more stability,'' said Arthur DeJong, mountain planning and environment resource manager at the resort.

Ski lifts typically last 25 years, DeJong said. To decide where to place new ones, the resort has run a mix of computer simulations to determine where the snow will likely be, based on varying calculations of how much the temperature might rise in the course of the next 30 years.

The resort has also developed an environmental plan. It is using mountain snow runoff to produce energy to run the lifts. Its ski village is car-free. And the resort has diversified beyond snow sports and now has a booming summer business, as do resorts in Utah and throughout the West.

But undertaking new engineering projects and buying the software to run computer simulations require money and expertise that are in short supply in much of the world.

''Adaptation is expensive, and the finances are a big challenge for a place like Kenya,'' said Judith Gona, executive director of Ecotourism Kenya, which is trying to make that country's travel industry greener.

''In recent years, Kenya has become a mass tourism destination,'' Gona said.

''Hotels were built to hold as many people as possible. Things like air-conditioning systems are not very efficient. It is difficult to put money into green, even if people know they should.''