Loading ...Biofuels threaten biodiversity
A recent study has shown that biofuel plantations, replacing forests, could take up to 600 years to offset the carbon lost through land conversion.
We all know the score by now: the climate is changing; the planet is warming; the ice caps are melting- surely we need to find an alternative energy source to dirty fossil fuels? Many believe the answer lies in the development of renewable and sustainable biofuels derived from crops. In response to this, much of the world’s rainforests have been replaced, whether directly or indirectly, by such plants. One particular crop, oil-palm, has overtaken soybean as the most traded oilseed crop in the world. Oil-palm plantations cover over 13 million hectares (over 50,000 square miles) and studies claim that up to 16% of recent deforestation in Indonesia is down to these plantations.
An international team of scientists, including Matthew Struebig of Queen Mary, set out to find whether oil-palm plantations are really worth their salt. The group used a set of formulas to estimate how long it would take for a plantation to actually have an effect on lowering CO2 emissions, taking in to consideration the emissions produced by establishing the plantation in the first place, as well as the carbon content of the original forestland. They also considered a range of influential factors, like the type of plant in the original forest and the method of forest clearance.
The study, soon to be published in Conservation Biology, estimated that it would take between 75 and 93 years for an oil-palm plantation to start having an effect on carbon emissions, depending on how the forest was cleared. This would also vary depending on the type of forestland it was replacing. Whereas it would only be expected to take around 10 years to offset the carbon balance when a plantation replaces degraded grasslands, the estimate rockets to 600 years when carbon-rich peatland is replaced.
What is more, the biodiversity of forestlands is also being threatened. Whereas forestlands house a rich diversity of species, few can survive the harsher habitat of the oil-palm plantations, let alone the human impact of agricultural intensification. Pollutants include fertilisers, insecticides, herbicides and palm oil mill effluent, all of which put pressure on existing wildlife.
The study included a meta-analysis, which found that fewer species of mammals, lizards, birds and plants flourished in plantations compared with forestland. The researchers estimated a staggering 80% species loss in such forest conversion. Frighteningly, these estimates are likely to be conservative if anything, due to the difficulty of species-counting in complex forestlands. There is also a time lag between habitat loss and extinction; wildlife that could perhaps survive for a short time may not be there for long.
The risks of oil-palm plantations to biodiversity have been picked up on by many charities and organisations. Friends of the Earth, who highlight at-risk species such as the orang-utan and the Sumatran tiger, go so far as to warn that the industry could result in the extinction of orang-utans within twelve years.
This “double jeopardy”, as the authors describe it, calls for a reconsideration of the current climate change combat strategies. Perhaps palm oil should be reconsidered as a biofuel, or at least planted in more carefully chosen places. Or as Matthew Struebig puts it: “We would be much better curbing our energy use in the first place.”
[...] opera una “doble incriminación” (tal y como lo señalaban los autores de una publicación de la revista Conservation Biology) en donde modelos de producción como este están [...]