* Tourism sector should do more to cut its carbon emissions
* Holidaymakers may shift to new destinations, seasons
By Alister Doyle
OSLO, June 17 (Reuters) - Climate change is a growing threat to tourism, from thawing ski resorts to coral reefs hit by warmer seas, and the industry itself should do more to curb its soaring greenhouse gas emissions, a study showed on Tuesday.
Tourism's greenhouse gas emissions, on current rising trends buoyed by ever more travel, are set to reach about 10 percent of the world total by 2025 from between 3.9 and 6 percent now, it said.
"The tourism industry will be severely impacted by climate change," according to the study by Cambridge University's Institute for Sustainability Leadership (CISL) and its Judge Business School and the European Climate Foundation.
Coral reefs, for instance, contributed $11.5 billion a year to tourism earnings and are under threat from warmer sea temperatures, rising sea levels and an acidification caused by a build-up of carbon dioxide in the atmosphere, it said.
And warmer winters are shortening winter sports seasons and threatening the viability of some ski resorts, according to the report which distils findings about tourism from studies this year by the U.N. panel of climate scientists.
Ski resorts can try to adapt by attracting summer hikers, for instance, or buy more snow making machines. "But it is hard to tell a positive story around ski resorts," Eliot Whittington, climate change director at CISL, told Reuters.
A few areas of the world might benefit from a shift in tourism, such as Alaska or northern Europe. And elsewhere, seasons may shift.
The report said the Costa Brava region of Spain's Mediterranean coast, for instance, was trying to draw tourists outside the summer months, responding to a lack of water and high temperatures during the high season.
The study also said there was some evidence of people traveling to new destinations at risk of vanishing in a warming world, such as glaciers, the Arctic, Antarctica or coral atolls.
"However, the opportunities presented by such 'last-chance' tourism will, by definition, be short-lived," the report said.
It also said that an increase of 1 meter (3 feet) in sea level rise this century - the upper bound of scenarios by the U.N. panel - would damage up to 60 percent of resort properties in the Caribbean and swamp many airports and ports.
"Every part of the industry needs to ... think about what more can be done to adapt to climate change, as well as how to continue the process of reducing the impact of their operations on the environment," Stephen Farrant, director of the International Tourism Partnership, said in a statement attached to the report.
Travel accounts for about 75 percent of tourism's greenhouse gas emissions. More efficient planes, vehicles and greener fuels could help curb emissions, it said. (Reporting By Alister Doyle, editing by Louise Heavens)