The idea behind offsets is simple: To compensate for the greenhouse gases your trip generated, you send money to a project that will reclaim carbon dioxide from the atmosphere or prevent it from being emitted at all. The cash might go toward reforestation in Brazil, an initiative to get cleaner cookstoves to people in rural Africa, or a methane-collection project. Dozens of organizations verify these causes, certifying that they’re actively reducing carbon and not just, say, protecting trees that would have been protected anyway.
Look for certification from Climate Action Reserve, the Verified Carbon Standard, or Gold Standard, all of which provide data that tell you how much carbon your dollars will offset. A wind-farm project, for example, averages about $1.90 per metric ton of carbon dioxide removed from the atmosphere, but improved forest management averages about $9.60.
Related: How To Figure Out If You Should Drive Or Fly
Are carbon offsets worthwhile? It depends on how you think about them. Environmentalists liken buying offsets to taking statins for high cholesterol: It mitigates the problem, but the long-term solution is to exercise and eat more vegetables—in other words, to change your behavior. “Do all the things you can to reduce your carbon footprint directly,” says Peter Miller, a senior scientist with the Natural Resources Defense Council. Buy energy-efficient appliances and bike to work. Call or email whoever represents you in Congress and tell them to support solutions for climate change.
Related: Is This The Future Of Emission-Free Travel?
So: This year, if possible, drive or take the bus to your holiday festivities rather than fly—traveling in a group if you’re in a car will emit less carbon, the Union of Concerned Scientists says—and then consider offsets. (We like the Colombian reforestation project.) Next year, if you really want to make a difference, consider celebrating at home.