Carbon offsetting is a method of counteracting the environmental impacts of carbon emissions by investing in carbon-reduction efforts. While reducing your fossil fuel consumption should be your first focus, individuals can purchase carbon offsets for air travel, cruises, big events, cross-country road trips, or everyday commutes-activities that increase your carbon footprint that you find difficult to avoid.

Individuals purchasing carbon offsets usually work through organizations such as CarbonFund or Climate Trust, which reinvest the money in specific projects. These projects are usually run by electric companies or construction firms. Offset project categories include :

• Renewable energy: Wind farms, solar installations, and other renewable energy projects.
• Energy efficiency: Projects that increase energy efficiency, such as improvements in manufacturing processes.
• Methane capture: Projects that remove harmful methane gas from the atmosphere, including manure collection and methane capture at landfills and coal-burning plants.
• Reforestation/sequestration: Planting trees, which store carbon and reduce greenhouse gases in the atmosphere.

Money can go to one project or to a combination of projects and types. Some providers allow investors to specify which type of project they prefer to support with their offset dollars.

Carbon offset programs vary in quality and efficiency. Knowing where your money goes and how it’s used is crucial in selecting programs. One important aspect to look for is “additionality:” whether the money supports new, unfunded projects that would only happen because of purchased offsets.

In its Consumers’ Guide to Carbon Offsets for Carbon Neutrality, Clean Air Cool Planet suggests asking carbon offset sellers these questions to help choose offsets wisely:

• Do your offsets result from specific projects?
• Do you use an objective standard to ensure the additionality and quality of the offsets you sell?
• How do you demonstrate that the projects in your portfolio would not have happened without the greenhouse gas offset market?
• Have your offsets been validated against a third-party standard by a credible source?
• Do you sell offsets that will accrue in the future? If so, how long into the future, and can you explain why you need to “forward sell’ the offsets?
• Can you demonstrate that your offsets are not sold to multiple buyers?
• What are you doing to educate your buyers about climate change and the need for climate change policy?

Know where offset projects are located. For Minnesotans, there’s more benefit in an offset provider that installs wind turbines in Worthington than one that plants trees in England. To ensure local benefit, we can bypass offset providers and donate to nonprofit organizations that directly support emissions-reducing projects, like The Minnesota Project’s anaerobic digesters or Honor the Earth’s Energy Justice initiative.

Carbon offsets are not a magic bullet for reversing global climate change. The more we learn about environmental impacts of air travel (see article in the Recreation section) and other sources of emissions, the more we see that the planet just isn’t big enough to plant enough trees and build enough wind turbines to completely counterbalance those impacts.

The most Earth-friendly travel mile is the one you don’t take.