Bioenergy can play a role in meeting climate mitigation goals, but that should be a limited role.
As industrialized nations worldwide continue to try and wean themselves off fossil fuels, and oft-touted solution is increased dependence on carbon-neutral biofuels. These fuels are inexpensive and renewable as they can be gained from our crops, which are certainly pros.
But there are cons, too. More need for biofuels like ethanol will entail an increased need to grow more crops, which will require plenty more agricultural land. In fact, warns the Intergovernmental Platform on Biodiversity and Economic Services (IPBES), growing demand for bioenergy could cause an 10-fold to 30-fold increase in green energy-related land use in coming years, according to a new report.
That would drive the loss of wildlife habitats, leading to massive biodiversity loss and the extinction of endangered species.
“The key issue here is: where would this huge amount of new land come from?” stressed Anne Larigauderie, a French ecologist who the intergovernmental organization’s executive secretary. “Is there currently such a large amount of ‘marginal land’ available or would this compete with biodiversity? Some scientists argue that there is very little marginal land left,” she added while addressing experts on an international symposium on biodiversity held in Egypt.
“This important issue needs to be clarified, but the demand for land for energy will almost certainly increase, with negative consequences for biodiversity,” Larigauderie said.
Bioenergy can play a role in meeting climate mitigation goals, but that should be a limited role. Instead, Larigauderie argues, industrialized nations should transition faster to low-carbon energy sources such as solar, wind and nuclear power. That way biodiversity worldwide could be better preserved, which in itself will be key to the mitigation of planetary warming.
Land-based ecosystems support diverse plants and soils, which sequester a third of annual CO2 emissions, especially by the help of tropical forests such as those in the Amazon. Meanwhile, the planet’s oceans sequester around a quarter of our annual carbon emissions.
That is why keeping forests intact and planting more trees is a better strategy at mitigating climate change than growing more crops for bioenergy. In temperate climates, one reforested hectare is four times more effective in climate mitigation than a hectare of corn used for biofuel, the IPBES observes.
“All methods that produce healthier ecosystems should be promoted as a way to combat climate change,” Larigauderie noted. “This includes afforestation and reforestation, as well as restoration — implemented properly using native species, for example.”