Fast-growing trees cultivated to produce biofuel are contributing to, not mitigating against, the looming catastrophe of climate change according to a new study in the journal Nature Climate Change.
Biofuels are often pushed by their advocates as a more friendly alternative to fossil fuel, but critics have long said that turning industrialized crops into fuels is rife with unintended consequences and part of a failed strategy for slowing global warming and climate change.
In this latest study, which looked specifically at fast-growing trees used for biofuel—poplar, willow and eucalyptus—scientists found that such species release high levels of the chemical isoprene into the air as they grow. Isoprene, when mixed with other pollutants in sunlight, forms toxic ozone and could affect crop yields, Reuters reports.
"Growing biofuels is thought to be a good thing because it reduces the amount of carbon dioxide in the atmosphere," Nick Hewitt, who worked on the study with colleagues at England's Lancaster University, told Reuters. "What we're saying is, 'Yes, that's great, but biofuels could also have a detrimental effect on air quality.'"
According to the study, "The impacts of biofuel cultivation on mortality and crop yields," published online Sunday, "Concerns about climate change and energy security are driving an aggressive expansion of bioenergy crop production and many of these plant species emit more isoprene than the traditional crops they are replacing."
The report examined a European Union effort to produce more biofuel in order to slow climate change—a plan that would reduce the annual value of wheat and maize production by $1.5 billion, since ozone impairs crop growth.
The report estimated that ozone from wood-based energy to meet the European Union's 2020 goal would cause nearly 1,400 premature deaths a year, costing society $7.1 billion.
Hewitt said there would be a similar impact wherever biofuels were produced in large quantities in areas suffering from air pollution.
The demand for biofuels in Europe was previously criticized by Oxfam in September, when the relief agency said government mandates for biofuels were pushing up global food prices and driving people off their land.