Large-scale cultivation of biofuels in Europe could lead to increased human mortality and crop losses. These findings, published online in Nature Climate Change, demonstrate that the wider implications of biofuel cultivation need to be assessed alongside their potential to save carbon.

Biofuels - usually derived from specialist crops such as poplar, willow or eucalyptus - constitute one of the alternative energy sources being advocated as part of the solution to society’s reliance on carbon-intensive fossil fuels. However, many plant species grown for biofuel emit more isoprene, an ozone precursor, than the traditional crops they replace.

A modelling study by Nick Hewitt and colleagues estimates the increase in ground level ozone pollution likely to result from a change to biofuel crops, and the associated impacts on human health and agricultural production. They conclude that proposed biofuel policies could have adverse consequences that should be evaluated alongside carbon budgeting considerations before large scale implementation.