Q. I have wanderlust, but I am cognizant of the impact traveling has on the Earth. The fuel required to travel makes me shudder. I also have guilt that I can afford to travel when so many are trying to simply get food on the table. Is there any way to reconcile privilege and disparity and have a smaller footprint when traveling? Please don’t recommend eco-tourism or the Peace Corps, and I don’t want to bicycle across America.

Wichita, Kan.

A. Dearest Kris,

Well, there’s always the Peace Corps. And cycling is a great way to see the country! Oh, wait … my head has clearly been buried in comparative BTUs-per-passenger-mile statistics for too long.

Many readers will relate to your dilemma, Kris. Travel is a wonderful way to expand one’s horizons and learn about different cultures, and it’s quite a bit of fun to boot. You’d never get to run with the bulls, see the Mona Lisa, or visit the Toilet Museum if you stuck to Wichita for a lifetime. But no way around it: Moving our bodies (and our luggage) from place to place emits a huge load of carbon dioxide. A full 32 percent of the U.S.’s carbon emissions belong to transportation.

The very best thing, climate-wise, would be never to travel anywhere. But that’s a no-go for most people, including yours truly — how I enjoy a nice getaway now and then. So if we’re going to travel, we can dramatically limit our emissions by booking our tickets carefully, as some modes of transport belch a lot more carbon than others. Your best bet, according to several analyses (including this one by the Union of Concerned Scientists) is taking the bus. (I’m assuming you’re traveling alone for this discussion; the math changes a bit if you’re on the road with a crew.)

Obviously, Kris, you’ll need lots of free time to make the bus work for you on long trips. And you will face certain geographic limits when choosing destinations. But the UCS report says a bus ticket will cut your carbon in half over driving a hybrid car and by up to 75 percent over flying, so do give it some thought. Hopping a Greyhound in your hometown will connect to you a bus network stretching all over the continent — New York City, Mexico City, Seattle, and Montreal are all just a ride (and perhaps a few transfers) away.

The train generally comes in second place for emissions for trips under about 1,000 miles, and it’s usually faster. And the nice thing about both buses and trains is that they run regardless of how fully booked they are, so by hopping into a seat that would’ve otherwise been empty, your ride doesn’t really add any more carbon to the air. You can’t get everywhere on public transportation, true. But the climate savings you earn this way are so great, it’s well worth taking the bus/train as far as you can, then renting as fuel-efficient a vehicle as possible to go the final distance. I don’t know your taste in travel destinations, Kris, but I’ll bet you’d discover all sorts of fascinating places if you chose your trips based on their transit accessibility.

It starts to get squishy from here on out. It’s sometimes difficult to figure out whether driving or flying is the better call, depending on the car, how many people you’re with, and how far you’re going, but planes and automobiles are generally the most carbon-intensive choices. So if you’re serious about reducing the emissions of your globetrotting, you’ll have to use them sparingly.

If you do indulge in the occasional far-flung trip, know this: Carpooling is much better than driving solo or as a couple, as you’re eliminating one or more other cars on the road. Ridesharing can be an excellent way to fill your seats with like-minded travelers. And the more efficient the vehicle, the better (no SUVs!).

When taking to the skies, fly nonstop and in coach for the lowest emissions. We’ve talked before about my mixed feelings on buying carbon offsets for travel. But if you’re dead set on flying somewhere, investing in a credible offset program or simply donating directly to local renewable energy projects or other climate-friendly endeavors brings a little silver lining to that cloud of carbon coming out of the exhaust.

Oh, darn, we’re out of time to discuss your other tricky question about travel-related privilege and guilt. Perhaps I’m not the best advice columnist for that one, anyway — may I suggest my colleagues The Ethicists?