Biofuels are gaining more and more ground as a replacement for fossil fuels. Especially because they are carbon-neutral or even reduce atmospheric CO2, but also because of the need for energy security and oil price spikes.
In their search for a non-food source for biofuel, the industry has been looking at forests. As an added bonus removing biomass from forests is also a way to prevent wildfires. But if cutting carbon emissions is the main goal, forest based wood is not the way to go, as a new study in Nature Climate Change shows.
The four-year study that was done in forests on the West Coast of the US is the largest and most comprehensive to date. As much as 19 eco-regions in California, Oregon, and Washington were examined encompassing 80 forest types of which 98 per cent are considered carbon sinks.
Not as carbon-neutral as assumed
Wood bioenergy is considered to be carbon-neutral, because wood winning and processing activities are compensated for by forest regrowth and reduced carbon emissions due to wildfire prevention.
The researchers however found that under optimal efficiency producing biofuel from forests releases 14 per cent more CO2 than continuing with current management practices. On a more realistic efficiency level this would even increase to 17 per cent. The team only found one scenario in which bioenergy production from forests would result in a positive result: whenever a forest’s sink capabilities are lowered to such an amount by a combination of insect infestations, reduced primary production or increased fire emissions that bioenergy production and other management schemes may jointly succeed in reducing carbon emissions and fire risk.
What are the alternatives?
This seems to bode badly for the use of wood as a feedstock for biofuel, but let’s consider the alternatives. A 14 per cent increase is nothing compared to the CO2 that would be emitted if fossil fuels would be used to produce the same amount of energy.
But still the other unwanted side-effects of bioenergy production from forests such as a negative impact on habitat, biodiversity and soils have yet to be properly examined, which might prove forests as a biofuel source even more unsuitable.
So while the story might prove different for other types of forest ecosystems, it seems that biofuel from forests will not help countries to reach their emissions reduction targets. As it appears finding a truly suitable source for biofuel is more difficult than it once seemed.
Luckily there do seem to be many other sources for biofuel like algae, agave and paper waste to name but a few that don’t seem to have as many drawbacks or at least only ones that can be overcome with some research and time.
© Jorn van Dooren | www.bitsofscience.org