More than 100 scientists sign letter seeking limits to biofuel expansion

In Brazil, ahead of the COP30 climate change negotiations, over 100 members of the global scientific community, including representatives from the Union of Concerned Scientists, have signed on to a letter calling on global leaders to limit a dangerous expansion of biofuels. The letter comes as Brazil seeks high-level support for a leaders’ pledge to quadruple so-called “sustainable fuel” use—including a doubling of biofuels consumption—as a major component of the international community’s response to the climate crisis.

But mounting scientific evidence shows that, far from being a climate-friendly solution as many governments claim, on average the energy source is today globally responsible for 16% more emissions than the fossil fuels they replace. By 2030, biofuels are projected to emit, every year, 70 MtCO₂e more than the fossil fuels they replace, the equivalent of putting 30 million new diesel cars on the road.

The letter also warns that such an expansion would have devastating environmental impacts in some of the world’s most biodiverse regions, consume scarce water resources, and contribute to agricultural runoff. Moreover, the scientists also caution that increased biofuels use will exacerbate global hunger by raising food prices, intensifying food price volatility, and diverting calories from human consumption. Curbing unrestrained biofuels use is not without precedent. In 2020, the EU agreed to cap conventional (first-generation) crop-based biofuels at a 7 percent share of its transport energy.