As hotels and resorts start to think green, airlines work to improve energy efficiency, and business looks for new technologies to help halt warming, Bill McKibben offers an impassioned overview of what it may really take to turn down the heat.

Just to let you know: I’m filing this article from Concourse B at O’Hare International Airport. I’m en route to Memphis to give a talk about global warming, which is a deeply ironic idea, like a dentist handing out lollipops to his young patients.

The bad news first, then. When we travel, we contribute to climate change. The carbon dioxide coming from the backs of our cars or our boats —or especially our planes—plays a substantial role in raising the earth’s temperature. In fact, it’s not too much to say that we’re putting at risk the very sights we’re traveling to see: the atoll where we relax on the beach is so threatened by rising seas that some island nations are preparing evacuation plans. The ski slopes in the Rockies and Alps are endangered by shorter winters and shrinking snowpacks—the same forces that will soon rob Glacier National Park of its remaining ice and melt the legendary snows of Kilimanjaro, revealing its less legendary rocks. As for the autumn foliage in the hills of New England, computer models show that if global warming continues on its projected course, sugar maples will begin to disappear from all regions south of the Canadian border by midcentury. At about the same time, if sea temperatures keep rising, the die-off of the world’s coral reefs will be complete. Those hot waters are also fueling the hurricanes knocking coastal resorts out of commission—and devastating entire cities. Meanwhile, the warmer seasons are drawing malaria-carrying mosquitoes into regions where they’ve never gone before.

And yet—and yet, we want to travel. We want to see the world, meet new people, learn about other cultures, widen our perspective; one of the sweetest gifts fossil fuel has given us is the sense of a larger world filled with beauty and diversity. There’s something more than a little sad about making it smaller again. We have already proved that we have the will and the power to protect nature under siege. Farmers, ranchers, second-home owners, foresters, investors, even developers make up the backbone of many of our country’s land trusts and nature conservancies, protecting millions of acres from unwise development; duck hunters have helped preserve hundreds of thousands of acres where waterfowl breed. Bird-watchers have turned flyway towns into sanctuaries where every resident knows that protecting the annual migration route means protecting their own livelihood. Now we must expend a far greater effort to figure out how to change a situation that has just as much destructive potential as an asteroid appearing from deep space: the worldwide reliance on fossil fuels.

There’s good news in the realm of travel, if not yet enough. Planes, for instance, have become more efficient over the past 40 years—but nowhere near as quickly as air traffic has grown. As the Economist has pointed out, a new Airbus 380 will use the equivalent of 3,500 passenger cars’ worth of power—as if each passenger were driving six cars across the Atlantic. According to the U.S. Department of Energy’s 2006 edition of the Transportation Energy Data Book, air travel by Americans (three fourths of it for pleasure) accounts for a little more than 12 percent of the country’s carbon output, and since it is emitting CO2 at high altitudes and adding other potentially heat-trapping chemicals, including nitrous oxide, the resulting brew could be two to four times worse for the climate than a similar dose coming from the tailpipe of a car.

How can those of us who love to explore the world participate in the effort to turn back climate change?Most of the ways we waste carbon are embedded in our economy; it’s hard to quickly double the insulation in every household, industrial plant, and office building in the world. But we can open up our definition of "leisure travel" to include carrying lighter loads of carbon. I had one of the best vacations ever a few years ago, when I just started walking out my back door in Vermont, traipsing 10 miles a day from one friend’s house to the next until, three weeks later, I’d covered my entire region. I learned more about where I live in those weeks of walking than in the five years I’d spent driving through it.

When we do travel farther, we can find out whether the companies that take us where we want to go are devising ways to limit their impact as well. Virgin Atlantic Chairman Richard Branson recently received a round of major publicity when he proposed a series of solutions to air travel’s contributions to global warming. What generated the most attention (and skepticism) was his idea to tow planes (with their jet engines off) between gates and runways, thereby addressing the fact that jets burn way more fuel on takeoff and landing than they do in the air. The company claims that if all the world’s airlines signed on to its plan—which also includes starting a plane’s descent earlier, to allow a steadier, more efficient speed, and reducing the weight of planes by using lighter materials inside and out—air travel-based carbon emissions could be cut by 25 percent, or 150 million tons a year. (For more on airline-industry efforts to curb climate change, see "What’s Up in the Air?"). In the meantime, we can always take trains when possible, and for that matter, rally local public officials to follow the example of Houston, Dallas, Nashville, Orlando, and a growing number of California cities, and use old railbeds for new public transit systems. Mark Ellingham, founder of the best-selling Rough Guides, recently announced that he is going to travel by train whenever possible and that all his guidebooks will come with a section on global warming.

Other players in the travel industry are also working on ways to mitigate some of the damage. It’s now easy to find opportunities to "offset" the carbon cost of traveling (see "Six Ways to Make a Difference" in the sidebar to this article). If you book a flight on Travelocity or Expedia, for instance, you’ll be offered the chance to balance your carbon use through companies that plant trees and build wind turbines and solar power facilities. You can also go online before or after buying a plane ticket and purchase such offsets independently. One leading firm, TerraPass, offers 1,000 pounds of carbon offsets—roughly the equivalent of a 2,000-mile round-trip flight—for $5.99; 5,000 pounds, enough to cover the carbon produced by flying from New York to Tokyo, go for $29.99. Carbon offsetting makes sense, and it’s bound to expand in years ahead. (The Web site estimates that consumer demand for offsets has increased more than tenfold since January 2006.) Europeans can already choose carbon-neutral car rentals from Avis, and British Airways became the first airline to offer every passenger the choice of offsetting. But offsets don’t solve the problem entirely. For now, their price is suspiciously cheap. That’s because so few people are engaging in the voluntary trade of emissions that the companies offering them can purchase carbon credits for very little money. Some of the offsetting actions, frankly, don’t amount to much; this is a field with no regulation or accountability. In any event, if offsetting is ever going to be big enough to make a measurable impact on the planet, then it will need to be mandatory. And good results will need to match good intent, which would run up the cost beyond the trivial range. The European Union is pressing to make international airlines cover the cost of their carbon emissions while flying over EU airspace. The U.S., which comprises 4 percent of the world’s population and contributes 25 percent of the planet’s carbon, is blocking the action.

For the moment, then, these carbon offsets are a decent salve for our consciences—and a real bargain, akin to the medieval practice of selling indulgences. But they will only represent a long-term solution to the planet’s climate crisis if joined by better and better technology and significant, international political action. That will require changing behavior. Which, in the long run, may be the most useful thing about travel: we see other approaches to the good life, ones that we can bring back home.

Consider, for instance, the implications of many travelers’ desire to visit Europe. When we want a taste of the good life, we head to France, to Italy, to Spain: elegance, sophistication, gastronomy. The places that entice us are societies that use, per capita, half the energy the U.S. does. Half is a big number, big enough to make a dent in global warming. The Europeans have no secret technology, of course, but they do have a subtle tilt toward community and away from ultra-individualism. Hence, their willingness to build and maintain cities that draw people in instead of pushing them out toward suburbs. The average resident of the state of Georgia uses a little more than twice as much fossil fuel per year than a counterpart in one of these countries just to get around. The Europeans have built great rail systems and trained themselves to use them, instead of feeling they must travel only on their own schedule.

It’s figuring out differences like these that can make travel worth its environmental cost. We need more ideas of the good life to guide us. And the travel industry is starting to provide more examples, including ecologically minded hotels and vacations offering the opportunity to work on environmental restoration projects. It’s our world—for the moment still rich, diverse, joyfully alive with an astounding array of biology and humanity. We who are here now will determine whether it stays that way—and whether those who come after us will marvel at the same bountiful earth.

The next installment of Travel + Leisure’s global warming series will appear in the March issue.

When airline mogul Richard Branson pledged last September to invest $3 billion worth of profits from his Virgin transport companies into renewable energy over the next 10 years, he signaled a shift in the dominant thinking about climate change. While politicians and industry leaders were scrambling to avoid discussing the effects of emissions from fossil fuels, Branson was sniffing out the opportunity for new business.

A few months later, Branson's proclamation—which included his proposal to reduce significant on-the-ground CO2 emissions by towing aircraft to the runways—is still reverberating throughout the industry. Although it may be years before Branson's freshly launched Virgin Fuels finds a renewable alternative to the gasoline used by jetliners, the industry may be poised to make significant efficiency gains soon—that is, if regulatory barriers and special interest groups can be moved out of the way.

The very idea of air travel still seems modern, but in practice, planes in the United States and Europe use outdated navigation technology and aging equipment. According to the Air Transport Association of America, if the FAA updated its ground-based air traffic–control system to a more sophisticated, digital, satellite-based program, airlines could follow much more efficient routes, reducing fuel consumption by 10 to 15 percent, and eliminating millions of tons of CO2. The FAA has upgraded some of its technology in recent years but has yet to commit to a complete overhaul.

Even the optimistic Branson was careful to hedge his investment over a 10-year period, and many analysts wonder if a commercial jetliner will ever fly on a bio-based fuel. But the airline industry continues to make incremental progress toward decreasing emissions. GEnx, GE's next-generation jet engine, expected to roll out in 2008, is made from titanium, carbon fiber, and epoxy resin and will be 15 percent more fuel-efficient than current models. Average fuel efficiency for domestic carriers has improved by 44 percent since 1990, and some are using lighter food carts and shedding trash compactors and in-flight phones to decrease weight. That may sound small, but consider this: Alaska Airlines found that by removing just five magazines per aircraft, it could save $10,000 per year in fuel costs. Sometimes a little goes a long way.

Aaron Clark

1. Offset your carbon output to theoretically cancel out the CO2 you are responsible for. You can buy offsets not just for air travel but also for your car. And keep your eyes peeled for the debut of the Bright Card (—a credit card that instead of offering frequent-flier miles or other rewards invests your money in alternative-energy projects.

2. Support green hotels and sustainable tourism companies. Visit national parks, and seek out hotels that have been certified by an independent third party for their environmental friendliness. Many places, and even some countries, rely on tourist dollars to preserve delicate ecosystems and indigenous communities. Visit for more information.

3. Choose public transportation whenever possible to cut down on auto emissions—according to a Department of Energy report in 2003, motor gasoline "has been responsible for about 60 percent of U.S. carbon emissions over the last twenty years." If you rent a car, look for companies, such as EV Rental Cars, that specialize in hybrid electric vehicles.

4. Leave the hardcover books at home. The wide variety of airplane types makes it impossible to quantify the impact of a passenger's luggage weight, but planes use more fuel, and thus produce more emissions, when they carry heavier loads.

5. Reduce your CO2 output at home so traveling will have less impact on your total CO2 load. Carpool to work if you can't take public transportation, order products online to cut down on trips to the mall, drive a hybrid car, and use fluorescent lightbulbs and energy-efficient refrigerators and washers. You can calculate your full carbon footprint on such Web sites as

6. Eat, drink, and buy locally—the goods you consume won't have been flown or trucked in, so you're saving significant emissions.

Aaron Clark