A new study in the US has underlined existing evidence that biofuels, designed to save emissions by replacing the petrol and diesel in our vehicles, can actually make climate change worse. By using a new methodology focusing on the flows of carbon, US researchers found that crops grown to recapture the equivalent amount of carbon released by biofuels only reabsorb 37% of the emissions. This means that biofuels used by vehicles result in a significant increase in emissions compared to the conventional fuels they replace (primarily because more CO2 is released upon combustion).

This paper confirms existing evidence that biofuels used in the EU as part of renewable energy targets could be increasing emissions instead of reducing them. A landmark study published earlier this Summer reached the same finding, although with a slightly different methodology.

Under its support system for biofuels, 4.75% of UK transport fuel is currently made up of biofuels. The EU has recently imposed new restrictions on the use of biofuels, including a 7% cap on the contribution of land-based biofuels (as opposed to wastes and residues, for example), the worst offenders. It also plans to remove the biofuels target after 2020.

When the UK leaves the EU the sustainability criteria for biofuels, and the cap on their use, need to be kept in place. In fact, the UK could choose to go further and restrict their use even more for the sake of nature and the climate. This new evidence only adds weight to the argument that they are a costly way of increasing emissions rather than reducing them, and better alternatives should be encouraged instead. Our recent 2050 Energy Vision report looked at what potential technology mixes could deliver the emission reduction we need in harmony with nature.