Burning oil and planting forests to compensate is more environmentally friendly than burning biofuel.

So say scientists who have calculated the difference in net emissions between using land to produce biofuel and the alternative: fueling cars with gasoline and replanting forests on the land instead.

The reason is that producing biofuel is not a “green process.” It requires tractors and fertilizers and land, all of which means burning fossil fuels to make “green” fuel. Environmentalists also worry that biofuel popularity will mean forests will be chopped down to make room for biofuel crops such as maize and sugarcane, releasing between 100 and 200 tons of carbon per hectare.