Carbon Offsets 101

As you pack your bags for vacation, chances are the carbon emissions of the aircraft you’ll fly and their effect on your carbon footprint are the last thing on your mind. Read on to find out how you can offset your travel long before you’re in vacation mode.

What is a carbon offset?

Planes emit carbon dioxide (among various other greenhouse gases), and, until a viable alternative to jet fuel is available on a large scale, there’s no way to completely eliminate carbon from air travel. That’s where offsets come into play. A carbon offset represents a reduction in emissions somewhere else, such as a landfill-to-gas energy project in New Bedford, or protecting forests in Madagascar. This balances the emissions from air travel, though you can also purchase them to offset other aspects of your lifestyle (natural gas, oil, electricity, and gasoline usage, among other things).

Where can I purchase a carbon offset?

There are numerous sites that offer carbon offsets, and a few airlines that offer the option to offset air travel. EasyJet gives travelers the option of purchasing offsets during the booking process. It then purchases an equivalent share in a UN-certified emissions reduction project. Qantas and Cathay Pacific also purchase offsets on the traveler’s behalf.

JetBlue and Virgin America link to Carbonfund.org, Continental and United link to Sustainable Travel International, and Air Canada sends travelers to Zerofootprint. Continental also allows you to offset cargo. No matter where you’re flying, you can probably find an airline offering offsets. You can also access these sites without going through the airlines.

Your other options include The Conservation Fund (Delta sends its travelers there) and TerraPass. Or, to simply calculate your carbon impact and learn more about ways you can reduce it rather than purchasing offsets, visit EarthLab.

How much does it cost?

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Most websites allow you to offset in two ways. The first is to donate a preselected amount ($5, $10, $20). The second is to calculate your carbon emissions based on your travel and/or activities to determine a specific donation amount. When you purchase carbon offsets through an airline, you often only get the option of offsetting travel, but sites such as Carbonfund.org offer the option of offsetting air travel, car travel, your home, or any combination.

When offsetting air travel, some sites give you the option of offsetting the effects of radiative forcing as well. Radiative forcing occurs at higher altitudes when an aircraft’s contrails form cirrus clouds, which more than double the emissions’ effect on global warming. Naturally, opting to offset radiative forcing costs more. According to Carbonfund.org, on a round-trip flight between Boston and San Francisco, a basic offset is $9.77, while an offset that includes radiative forcing totals $26.38. Ecobusinesslinks.com gives you a general idea of what offsets cost per metric ton of carbon dioxide on various websites.

How is it calculated?

The way emissions are calculated varies by site, and most give an explanation as to how they generate the cost of an offset. Carbonfund.org uses statistics from the U.S. Department of Energy’s Energy Information Administration, while Cathay Pacific uses historic fuel consumption data to determine carbon dioxide emissions, then divides this number by the total passengers on the plane (based on historical averages) and the distance flown to determine the amount of carbon dioxide per passenger kilometer. Qantas takes it a step further and factors in emissions from ground operations such as catering centers, terminals, ground vehicles, and engineering facilities. There is no industry standard as to how emissions are calculated, so there is potential for variation.

Where does my money go and can I choose where it goes?

Once you purchase a carbon offset, your donation supports renewable energy sources, energy efficiency, and/or reforestation projects. Some sites allow you to choose what types of projects your money goes toward, while others choose for you. For example, both Carbonfund.org and Sustainable Travel International allow you to choose whether your donation goes toward reforestation/preventing deforestation, renewable energy, or energy efficiency projects.

How do I know my money is going to a reputable project?

• Do your research. Before you purchase offsets, review the organization and its projects.
• Look for nonprofit organizations and Gold Standard certified projects.
• Make sure the organization and its projects meet third-party certification standards and are verified and audited by third parties.
• Check that the organization retires carbon offsets instead of reselling them.

Have you ever purchased a carbon offset? Do you think they are a good idea? Share your thoughts and advice by leaving a comment below!