Squishy Science

Carbon offsets are a less than optimal way to reduce your carbon footprint.

- Miriam Cross

ON THE LIST OF ACTIVITIES THAT FORM our carbon footprint, from air-conditioning to eating meat, air travel is near the top. Short of refusing to fly— as Greta Thunberg, the Swedish teen activist, did when she traveled from England to New York in a carbon-neutral sailboat—you can pay a third party to plant trees, destroy methane or build wind turbines in a bid to counterbalance the damage your flight has done to the environment.

Carbon-offset sellers will calculate your carbon footprint, whether you travel by bus, car, plane or train, and translate the tons of carbon dioxide emissions triggered by your trip into a dollar figure that can help fund carbon-reducing or carbon-prevention projects around the world.

Buying carbon offsets is not expensive, especially for short hops. But figuring out how effective your purchase is isn’t easy.

Different shades of green.