For decades, global citizens — those of us who believe humanity is something that transcends nation, race, and creed — have seen travel as a force for good. Travel, we reason, takes us out of our bubbles and comfort zones, it confronts us with other cultures and other ways of living. It forces us to recognize the common humanity we share with groups of people that our culture otherwise depicts as caricatures and stereotypes.

It is, as our favorite Mark Twain quote says, “fatal to prejudice, bigotry, and narrow-mindedness.” “The world is a book,” we say, quoting St. Augustine, “and those who don’t travel only read one page.”

We have a lot of quotes to back us up, and a lot of good science, as well. We know travel makes people more creative. It makes them less racist, more trusting, more humble, and so on and so on.

Likewise, travel and tourism are much-needed sources of income in many parts of the world. Travel can revitalize a flagging economy: take Iceland. After the recession of the 2000’s, Iceland’s finance-heavy economy was in shambles, so it turned to tourism to help pick up the slack. Ten years ago, how many people did you know who had been to Iceland? And how many people do you know who’ve been there today?

In spite of all of this, there’s an argument to be made — if we truly want to be good global citizens — that we should actually be traveling less.

The environmental argument

We’ve known for a long time that travel, particularly by plane, is not good for the environment. A single cross-country or transatlantic flight generates 2-3 tons of emissions. Americans, on average, produce 19 tons of emissions a year. Some modes of transport are greener than others, but in a warming world, it is worthwhile to ask the question: does the damage done to the atmosphere by our travels outweigh the good being done to us when we travel? That may be like comparing apples and oranges, but put it a different way: if everyone could travel exactly as much as they desired, what would it do for the planet?

On top of emissions, a second problem has arisen at the end of 2017: Instagram swarms. The issue is simple: travel Instagrammers post a photo of something amazing out in the wild. They geotag it, and the picture gets liked thousands of times. Another photographer goes there, takes another amazing picture. That photo gets liked tens of thousands of times. And over time, a certain location — like Horseshoe Bend in Arizona, or Trolltunga in Norway — can go “viral,” and suddenly, it is being flooded with tourists.

But because the flood came suddenly, the authorities had no time to prepare. Horseshoe Bend, a famous travel Instagram spot, used to get 1000 people a year. Now, it gets 4000 a day. Now, they have to put in a new parking lot. Ten years ago, we were all shocked to hear that Machu Picchu, lost to the world at the beginning of the 20th century, was now at risk of being destroyed by floods of tourists. Now, those tourist hordes have basically been weaponized by social media.

Nature, of course, belongs to everyone, and no one should be denied the chance to see the world’s beautiful places. But it serves no one if we enjoy nature to death. There’s an economic and ecological concept known as “the tragedy of the commons” that helps illustrates the problem here. The idea is simple: if everyone acts in their own short-term best interest when it comes to using a finite resource, they actually deplete that resource, which is worse for everyone in the long run. So, say I share a water cooler with everyone else in my office. I need a lot of water, and the best thing for me, personally, is to take as much water as I can, every time I go to the cooler. But everyone else in the office realizes I’m doing this, so they start taking as much as they can whenever they go, too. Very quickly, we run out of water, and, because the company only refills the cooler once in a while, we all end up drinking from the sink with the weird taste.

That example gets much more dire when it’s applied to things like the air we breathe or the fuel we use to power our cars. But it could easily be applied to travel. It is undoubtedly better for you, as a person, to travel as much as you can, to see as much of the world as possible. But if we all do what is only best for us, and don’t consider what’s best for the world as a whole, we all end up worse off. So ancient sites like Machu Picchu fall apart because of floods of tourists. The pyramids are reduced to dust as thousands of travelers chip a piece off of them for souvenirs. The Grand Canyon gets clogged with the garbage of sightseers. And the air is filled with the toxic emissions of a million planes, all taking their passengers to exciting, new, consciousness-expanding destinations.

The cultural argument

Another travel truism for decades has been that tourism helps local economies, so when we travel, not only are we doing a great job in breaking down cultural barriers, but we’re also doing amazing things by injecting some much-needed cash into struggling countries.

There is, undoubtedly, some truth to this — tourism is good for the local economies. But as anyone who has lived in a tourist town knows, travel alters your existence in some pretty frustrating ways. I lived for two years in Asbury Park, an increasingly popular Jersey Shore seaside town, and while our economy was totally dependent on tourist dollars, we, the locals, were also not hugely thrilled when hordes of non-locals came into town. In the summer, bros would have fights and puke on our lawns. They’d overcrowd our favorite bars, they’d blast shitty music on the beach. In the winter, gangs of roving Santa Clauses would binge drink at the SantaCon pub crawl and then puke and defecate in our alleyways.

We depended on them, but we also kinda hated them. Because while Asbury Park has an amazing local culture, that culture is often cannibalized by the tourists. It is hard to have a local event when 95% of the attendants are going to spend a grand total of three days of their lives in your town. I’ve seen this dynamic play out in every other big tourist town I’ve spent a significant amount of time in (London, Washington, D.C., New York, Beijing, Buenos Aires). The places tourists go are cultural dead zones.

Some cities have begun to wage war on tourism, rejecting money in the name of cultural preservation, and none have done it more spectacularly than Barcelona, where young locals have been slashing the tires of bike shares and tour buses, and where massive protests have broken out against sites like Airbnb (the jury’s still out on how true this is, but it appears “sharing economy” sites like Airbnb may play a big role the massive increases in rents in some cities in recent years). We can debate how reasonable these complaints are, but it’s at least worth considering — is our economic benefit the only one that should matter to the places we visit?

David Foster Wallace, in a footnote on his famous “Consider the Lobster” essay, puts it this way: “To be a mass tourist, for me, is to become a pure late-date American: alien, ignorant, greedy for something you cannot ever have, disappointed in a way you can never admit. It is to spoil, by way of sheer ontology, the very unspoiledness you are there to experience. It is to impose yourself on places that in all non-economic ways would be better, realer, without you. It is, in lines and gridlock and transaction after transaction, to confront a dimension of yourself that is as inescapable as it is painful: As a tourist, you become economically significant but existentially loathsome, an insect on a dead thing.”

That might be stated slightly more curmudgeonly than it needed to have been: Wallace was notoriously grumpy about tourism, and one of his other essays, “A Supposedly Fun Thing I’ll Never Do Again” about cruises remains one of the best pieces of travel writing, or possibly anti-travel writing, of all time.

But the point is a valid one — Americans have a tendency to reduce our value to economic measurements, and it’s possible that our lives and presences on this planet are about more than our contributions to GDP growth. In the act of tourism, if our presence is actually diluting the authenticity of a place, if we’re eroding the local culture by becoming ham-fisted, inexperienced participants in it, then maybe it’s not a totally good thing. If locals in places we’re visiting don’t really want us there but feel economically obliged to put up with us, is that really “breaking down barriers between cultures”?

So what should we do?

Tourism is a massive industry, and travel in the US and internationally is shooting through the roof. There are undoubtedly benefits to travel, and all of us want to see as much of the world as we can before we die. But good global citizenship means making some personal sacrifices for the greater good.

Maybe that means foregoing long flights and traveling more locally. Maybe it means putting off short trips in order to take big long ones — say, every time you make a career move, you carve out a 3-month interim period where you’re just gonna do all of Europe. That way you’re not making a dozen trips back and forth over a lifetime.

Or maybe it just means staying at home and working in your own community. Everyone should travel in their lives, it’s true — but maybe, if you’ve already seen a lot of the world, take a few years off and let kids who have never left their hometown go instead.

The fix to the problem of mass tourism, if there is one, will likely have to be a bit more systemic. But we should at least start thinking about what our travel does to the world, and stop thinking of it as a shortcut to world peace.