BURNING trees and other plants, combined with artifical methods of carbon capture and storage, could help reverse global warming in the future, experts will say today.
Scientists in Sweden have predicted that greater use of trees in biomass could help push down temperatures.
Trees naturally take in carbon dioxide while they grow, and when they are burned, they do not release any more cabon dioxide than they absorbed.
The researchers believe greater use of biomass, requiring more trees, combined with carbon capture initiatives, would reduce the emissions which trigger global warming.
Researchers at Chalmers University of Technology found that even if nations fail in their joint pledge to keep temperatures to a global limit of 2C above pre-industrial levels, large-scale use of bioenergy, and carbon capture and storage (CCS) by 2050 could reverse that trend within 100 years. However, environmentalists warned that increasing use of biofuels would “trash” what was left of the world’s forests and jeopardise key farmland needed to grow crops to feed rising populations.
And even the study’s authors warned their findings, which are based on computerised models forecasting future scenarios, should not be used as an excuse for governments failing to do more to cut emissions in the short term.
Professor Christian Azar, who co-authored the study, said: “What we demonstrate in our paper is that even if we fail to keep temperature increases below 2C, then we can reverse the warming trend and push temperatures back below the 2C target by 2150.
“The most policy-relevant implication of our study is that even if current political gridlock causes global warming in excess of 2C, we can reverse the temperature trend and reach targets later.”
But he cautioned that temperatures could also only be reduced by around 0.6C per century by taking carbon out of the atmosphere in this way.
This means that the method could not be used as an “emergency brake” if the damage was already too great.
Burning trees and plants as a source of energy on a large scale in around 30 to 50 years could allow the world to meet targets to limit temperature rises at a lower cost, the study published in the journal Environmental Research Letters found.
However Lang Banks, director of WWF Scotland, said: “Intensifying our use of bioenergy at the scale proposed by this study would be a surefire way of making sure we trash what remains of already threatened forests and put at risk precious land and water needed to grow food.”
Dr Vivian Scott, an expert at the Scottish Carbon Capture and Storage Centre in Edinburgh, added: “This should not be seen as a get out of jail free card.
“Modelling studies like this are interesting but these are just scenarios which are not guaranteed by any means.”
A Scottish Government spokesman said biofuels were part of the solution but stressed that they should be used on an “appropriate” scale.
The UK government is looking at a number of carbon capture options, such as the Captain Clean Energy Project, at Grangemouth, which would involve storing carbon offshore in depleted gas fields