Can the travel and tourism industry help solve the world's problems? Or is it, itself, a big problem?

Yes and yes.

Obviously, tourism when done right can be a force for economic growth and global understanding. But hotels can be blights on the landscape (ever been to Cancun?) and air travel is a significant contributor to global warming, with no short-term clean fuels in sight.

Monday, the Conde Nast Traveler magazine brought together executives in the hotel, airline and travel industries to explore those questions, at an event known, immodestly, as the World Savers Congress. (I half expected to see people in Superman and Batman costumes appear at the august Council on Foreign Relations in New York.) The half-day of conversation revolved around issues big (tourism as a force for peace in the Middle East!) and small (why do hotels put shampoo in millions of little plastic bottles?).

Conde Nast showcased some big names. Richard Branson -- surely the leading environmentalist in the travel industry, as the founder of Virgin Atlantic and Virgin America -- talked about his efforts to "green" jet fuel and took a few shots at the U.S. airline industry, while Tony Blair made a pitch for the travel industry to invest more in Israel and Palestine, to help provide an economic platform upon which peace can be built.

Branson, whose demeanor is more low-key than his appearance might suggest, said that 85,000 commercial aircraft take off and land every day, contributing 3 to 4 percent of all greenhouse gas emissions; the airline industry, while not profitable, is nevertheless growing at a robust rate, and will continue to do so. "People have got to travel," he said.

The only solution, he said, is greener jet fuels. Back in 2006, Branson promised to invest all of the profits from his airline and train businesses, up to $3 billion, into a new company called Virgin Fuels, which is developing biofuels. He probably won't get to $3 billion, he conceded, but after mis-spending some money on corn ethanol (his words, not mine), Branson is now focusing on research into isobutanol and algae. (See Gee Whiz, Algae! about Solazyme, a company in which Branson has invested.)

"Algae could be a very good aviation fuel," Branson said. "Producing algae, en masse, with $100 a barrel oil, should be very competitive."

All airline and hotel companies should pledge a portion of their profits to developing clean energy, Branson said. This shouldn't be viewed as charity, but as an investment in the future. "If governments aren't doing anything, it's up to us entrepreneurs and business people to invest," he said. This is a theme we'll be hearing a lot more in the months.

Branson also voiced support for more research into geoengineering. (See Is Geoengineering Inevitable?) "If we are spiraling out of control, we should be thinking about geoengineering," he said. "Are there ways we can create more rainfall that could cool the world down, for instance?"

Branson also couldn't resist taking a shot or two at his U.S.-based competitors. Virgin America is doing well, he said, because it is service-oriented, as are many European and Asian airlines. "In the airline industry in the states, that hasn't been the case for some reason," he said. "It's bizarre…May it continue forever, please."