Should You Buy Carbon Offsets?

For consumers looking to shrink their personal contribution to climate change, the opportunity to counteract the environmental cost of air travel and other fossil fuel-guzzling activities offers a dose of hope. Such is the promise of carbon offsets—a set of credits purchased from projects that are designed to reduce greenhouse gas emissions.

What are carbon offsets?

Offset projects encompass a range of initiatives that actively conserve forests, wetlands, and grasslands (all of which store climate-warming carbon dioxide), or which otherwise reduce emissions from sources like landfills, farms, and coal mines. If you’ve purchased plane tickets in recent years, you’ve almost certainly been given the opportunity to buy carbon offsets. Some airline websites, for example, offer the option to buy them from third-party sellers like Terrapass, Native Energy, Green E, or Cool Effect, which provide calculators to estimate the amount you need to neutralize the footprint of your trip. Should you buy them? Yes, but selectively. Low-quality carbon offsets were once common, so you first have to do some legwork to ensure authenticity.

How do carbon credits work?

Each carbon offset credit is associated with the emission reduction from a specific project, and a single credit typically represents one metric ton of carbon dioxide (the equivalent of driving 2,513 miles in an average gasoline-powered car). Around the globe, forest conservation projects are the most common type of offset project. They most often feature a property owner who gets paid to preserve, re-plant, or delay the development of their land. A company will purchase credits from these landowners that represent the avoided emissions to compensate for its pollution. The money the landowner makes from selling the offsets is used to pay for the cost of implementing the project and maintaining it over time, providing a financial incentive to conserve the forest as opposed to cutting it down.

As a consumer, it’s important to choose offsets that are carefully designed and diligently implemented and measured—lest you end up buying into a scam.

How can you ensure you’re supporting a quality carbon offset project?

Let’s consider a hypothetical example, in which the offset seller will give your money to a landowner in the Amazon who promises to leave his trees standing to maximize carbon sequestration.

The offset seller should make several guarantees in this transaction. First, that the offsets are real—that there’s an actual landowner who owns actual land with actual trees. This guarantee shouldn’t be necessary, but unfortunately there have been cases of groups collecting money for offset projects that don’t yet exist. Relatedly, the offset should be verified and enforceable—a third party should have laid eyes on the trees, and there must be a mechanism for penalizing the landowner if he doesn’t follow through. The offset should also be permanent. If the guy who gets your money can burn his trees to the ground six months later, your money will have been wasted.

Finally, the offset must be additional. This is the trickiest issue with carbon offsets. What if the Amazonian landowner never had any intention of clear-cutting his land in the first place? Then your purchase would be a gift rather than an offset. The landowner would be taking advantage of the offset system to collect a windfall for doing exactly what he would have done anyway. Your transaction would have no effect on the amount of carbon in the atmosphere.

A corollary to “additionality”—yes, carbon offset wonks use that word—is leakage. Let’s say your money prevented the Amazonian landowner from selling his plot to a logging company. That’s great, but what if the logging company simply bought the plot next door? That’s leakage. Your offset dollars shifted deforestation rather than preventing it.

Both individuals and corporations buy carbon offsets. Big companies have the resources to research the legitimacy of an offset themselves. Google, for example, employs people to investigate the quality of the company’s carbon offset outlays. You probably don’t have the time or money to fly to Ecuador and poke around a forested plot, to inspect a methane capture system, or to visit an urban forestry project. Fortunately, a quality assurance system has developed to verify the quality of your offsets. At the top level are standard-setting groups, such as the Climate Action Reserve, which establish rules and protocols for offset projects. Below them are retail certification programs, like Green-e Climate, which help individuals identify reliable carbon offset sellers.

The best carbon offset programs are transparent. If you have concerns, you should contact the seller to find out exactly what you’re buying. Many will allow you to direct your money to specific projects or away from others. You may, for example, prefer not to invest in a factory farm, even if the money is earmarked for methane capture. Or you may wish to look for programs that offer benefits beyond carbon reduction, such as employment in low-income areas or improvements in public health.

What about the ethics of carbon offsets?

In addition to the practical issues, you should be aware of a larger philosophical argument about carbon offsets. While proponents view high-quality offsets as a way to support carbon-fighting projects, critics say they are merely a license to pollute. When you buy an offset, you are paying someone to cut her emissions so you don’t have to.

That’s why your first move should always be to reduce your own emissions. Drive fewer miles, fly less, don’t overheat or over-cool your home. And as you continue to find new ways of treading more lightly on the planet we call home, know that high-quality carbon offsets are available to eliminate the last traces of your carbon footprint.

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