Sustainable travel, the idea of leaving a minimal impact on the places we visit, has become increasingly popular in recent years; so much so that the United Nations declared 2017 its Year of Sustainable Tourism worldwide. It has become especially trendy among younger travelers who want to feel a sense of social conscience on their vacations. The subcategory of voluntourism alone is worth more than $2 billion per year, and entire tour groups have organized around ecotourism adventures.

The upshot is that the Internet is filled with tips for would-be responsible travelers. Some are fine. Some are forgettable. A few are utterly ridiculous. A few are well worth considering though.

Track Your Plastic and Carbon

Siem Reap, Cambodia, is a tourist boom town. In just a few short years the number of visitors who pass through each year on their way to the nearby Angkor Wat temples has leaped to more than 2 million, causing the government to consider a cap on visitors to the park and hoteliers to join a local land rush.

One of lesser noticed byproducts of this traffic has been the Refill Not Landfill project, in which businesses across the city set up free stations for visitors to top up reusable water bottles instead of buying new ones. It's a clever move for a town which historically has tossed out more than 4.6 million plastic bottles per year, and a good first step for thoughtful tourists too.

Keeping track of your environmental impact isn't always easy, especially while traveling. It's just harder to set and follow your own rules in someone else's country. Try, though. Instead of buying plastic water bottles, refill old ones. Carry a day bag instead of taking plastic ones in the market. From time to time look up a train instead of flying. Each decision might seem small, but over time the little things add up.

Give Smart

"Many well-intentioned travelers bring sweets, used clothing, books and pencils to hand out to children and villagers in developing nations," writes National Geographic's Costas Christ. "Sadly, this kind giving often has unintended consequences -- it can sow community conflict and encourage a culture of dependency and begging. I watched two Maasai women in Africa fight over a t-shirt that a smiling tourist had handed out; in some parts of Asia, the first English words children learn are 'Give me sweet.'"

Instead, Christ pointedly suggests that travelers focus on helping to develop institutions. Do some homework to find local organizations with a strong reputation, then either donate money there or reach out to learn what they need.

No, you won't get that social media-ready selfie handing out candy to a bunch of local children, but that's kind of the point. Don't give so you can be seen doing it on Instagram. Five minutes making a PayPal donation through someone's website can almost always do more real good than an entire afternoon spent handing out small toys, even if it may not feel as viscerally satisfying.

Behave Like A Guest

"Be respectful of the biological, ethical, cultural and sexual diversity of the communities living where you are traveling. It's not your home, and it is worth doing a bit of homework about where you will be traveling."

This advice comes courtesy of Project Cordillera, and many tourists forget exactly how important it is.

People in different parts of the world think and behave very differently. As a guest in someone else's country it's not your role to judge or ignore rules just because you may not like them, but plenty of travelers do exactly that. In many Muslim countries it's common to see westerners dressed informally even while visiting mosques and temples, in defiance of Muslim code of dress. Amorous couples have displayed their opinion of Italian laws against public displays of affection.

Returning to Angkor Wat and the socially conservative Khmer culture, the government has actually had to crack down on tourists for taking nude photographs at the Angkor monuments.

You wouldn't behave this way in someone else's home. If a friend asked that guests remove their shoes when coming over for dinner, you wouldn't argue that you feel underdressed without footwear. It's no different while in another country and culture. You've taken the time and effort to arrange a trip overseas. Now put in a few more minutes to learn a little about the culture you'll soon visit. It's just basic courtesy.

Do. Not. Teach. English.

Here is a list of the professions which have real contributions to make during a brief visit to another country: Doctors, nurses and rock stars. Are you a medical professional or the lead singer for a chart-topping band?

Because unless you can hold a clinic giving out free physicals, or can't get a beer without someone asking for a song, the odds are you have little to contribute during a 10-day vacation. Nevertheless, NGOs get requests frequently from travelers, particularly backpackers, looking to do volunteer work while visiting a developing nation community.

Almost always they want to teach English. (Some even more poorly informed tourists want to "play with the children" at local orphanages. The less said about this ignorant, arrogant approach to other human beings the better.)

No organization needs you to show up for a few days and teach English.

Teaching is one of those jobs that just about everyone thinks they can do, and they're almost always wrong. This is a demanding, high-skill job. Teachers need to spend the time necessary to build up a rapport with their students and the continuity required for a meaningful lesson plan. Otherwise, you're just another in a rotating cast of western faces who show up to take a couple selfies, recite the days of the week (for the hundredth time) and jet home with a feeling of unearned self-satisfaction.

So yes, if you are a trained and qualified instructor, then by all means send a few e-mails to see if there's something you can offer. Or if you plan on spending at least several months in one place, long enough to receive training and teach an entire term, then you very well may have something valuable to add.

Otherwise, enjoy your vacation, spend some money, and make a donation to a worthy cause.

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