For me, sustainable tourism ultimately means that travelers are interacting with a destination in a way that is mutually beneficial for the traveler and for the locals. At the end of the day, the locals will welcome future travelers, because they see value in their visits. (from "What sustainable tourism really means, Part I")
Economically sustainable tourism is where my passion lies. I studied international development economics in college, and spent a summer in Tanzania volunteering with a local business (PS, I am writing an essay about that experience for an upcoming book… stay tuned!). When I travel, I have developed a reflex of thinking about how local people make their money and whether or not it seems to be healthy for their economy. As travelers, we can do a LOT to support local economic sustainability, which essentially translates into independence for the local people in the places we visit (versus a version of economic colonialism, where foreign powers hold the purse strings).
One thing we can do is avoid all-inclusive resorts*, especially if they are an international chain. These resorts may hire some locals, but the higher management staff is often comprised of foreigners, sometimes specifically flown in for that job. And rather than visitors going out to patronize local businesses, they may well end up doing their dining and shopping on-site. To combat this, Puerto Rico has started issuing restaurant coupons to dine in local establishments, in order to coax travelers away from other Caribbean islands with large resorts.
Also, be aware where you are doing your shopping. Are you really in a local market, or are you in a touristy hub where the prices are jacked up?** Could you go to the smaller market a bit further away and support sellers who don't generally get the big tourist dollars? In Cairo, the Khan al-Khalili market is the big tourist draw, and yes, it is pretty fun and full of sparkly objects that pulled me in like a tractor beam. However, if you ask around, you'll find out that it is nicknamed the "Chinese market," because so many of the goods are, yep, made in China. Just around the corner is what is known as the "Egyptian market," where actual Cairenes buy food and staples from one another. It is less crowded, and certainly less glittery, but we scored street cred points for shopping there, and supported sellers who don't get the same foot traffic as the main market.
The made-in-China issue is a big one. Where are your goods coming from? Are you buying imported foods and souvenirs? Or are you really supporting local farmers and craftspeople? See, the destinations we visit, particularly those in the developing world, need independence from the occasionally very high import tax of many of these goods, as well as the job creation of producing these goods themselves.
Global money, strings attached
When I lived in Prague in 2007, I was still an undergraduate. I had finished college a little early, and so took a semester off and found a job analyzing European Investment Bank (EIB) loans to African nations for environmental development projects. I learned much during that job that I almost wish I hadn't… see, the EIB (and the World Bank and IMF) have an seemingly altruistic tendency to give out loans to less wealthy countries for these projects, whether they be hydroelectric dams (which alternately dry out and flood large areas, dramatically altering local people's ability to live near them and occasionally causing mass relocations***), wind turbines, or whatever else, but these loans come with very real first-world strings attached.
Often the interest rates for these loans are far beyond what developing nations can pay (but they are stuck between a rock and a hard place, needing the initial cash infusion to get any new project accomplished), foreigners are flown in for project management, and because skills are never transferred to local people, foreigners must be kept on to run the project for years afterward, stunting or cutting off local job creation and income growth. I had my distaste for these loans confirmed last year when I found myself living with the former deputy secretary for education from Sierra Leone — Abbas and I had long talks about how (at least in his experience and mine) African nations were being taken for fools by these international financial institutions (IFIs).
This post has gotten wicked long, but I hope you're still with me. Say you are a traveler visiting Nigeria, and a major EIB-funded power station is providing your electricity. Every time you use electricity, you are helping fund a system that may not actually be beneficial to the Nigerian people (this is hypothetical, by the way). As foreign travelers, we have the ability to ask questions about these projects, and talk about our findings to a broader audience (on a blog, for example?). We can also do our research ahead of time, and support municipalities and governments that are supporting their constituents.
Okay, researching the local power supply may not be fun (or even easy information to find…), but it is this sort of awareness that can make tourism a profitable and sustainable endeavor for travelers and locals alike. And frankly, if travelers really want to call themselves "eco-conscious," they need to realize it goes far beyond recycling and taking public transport.
*I also just personally hate all-inclusive resorts. You can sit on an anonymous beach and eat a continental breakfast anywhere, dammit. Go be adventurous.
**And if I sound like a grumpy old man, it is only because grumpy old men are my spirit animals.
*** Read "Power Politics" by Arundhati Roy if you want to learn more about this stuff. It's an awesome, fast read.