You can’t lose weight if you pay others not to eat.

Don’t buy carbon offsets, says Mark Jaccard.

Those wind turbines you are helping to fund in India could be improving people’s lives. But they aren’t likely to save the warming atmosphere from the extra load of carbon dioxide your flight is set to release.

“The research suggests a lot of what we’re calling reductions are not real,” says Jaccard, a Simon Fraser University professor and one of the country’s leading experts on sustainable energy. “Offsets don’t work.”

Carbon offsets are payments to projects that, for the most part, build clean energy, or reduce dirty energy use in the developing world. For instance, someone might make a financial contribution to a wind farm to compensate for greenhouse gas emissions caused by a personal air flight.

Essentially, offsets allow you to pay someone else to cut back their greenhouse gas emissions use so you don’t have to.