REDUCING DEFORESTATION in the world’s tropical rainforests is “essential” to limit the rise in global average temperatures to 2 degrees, an international conference on climate change has heard. The 2 degree limit is a key objective of the EU’s climate policy.
In two papers presented at the conference, hosted by the University of Copenhagen, senior scientists from the British Met Office said deforestation needs to be avoided even if good progress is made in reducing carbon dioxide (CO2) emissions.
“If strong policies for avoided deforestation are not implemented, the probability of achieving a 450ppm CO2 target, and hence the EU 2 degree target, is very low, even in the presence of the strongest mitigation action on fossil fuel emissions considered feasible,” states one of the papers.
The chances would fall from close to 50 per cent even if the UN’s reducing emissions from deforestation and forest degradation (REDD) programme was implemented to less than 20 per cent if current rates of deforestation continued to below 3 per cent with complete tropical deforestation.
“A completely successful REDD policy would avoid 0.6 degrees of temperature rise in 2100,” according to one of the papers. But if current trends of tropical forest loss were to continue, CO2 concentrations in the atmosphere would reach 550ppm – implying a rise of 3 degrees in average temperatures.
It noted that land use change accounted for 17 per cent of global greenhouse gas emissions in 2004, and said continuing deforestation could lead to estimated releases of 450 to 800 gigatonnes of carbon into the atmosphere, of which 395 gigatonnes could arise from tropical forests.
As the authors said, present trends of deforestation in most tropical countries such as Brazil and Indonesia “show little sign of abating”, while reforestation in temperate countries such as Australia “may be offset by release of carbon due to projected increases in forest fire frequency”.
Another Met Office paper by Jemma Gornall noted that tropical rainforests – the world’s most important “sink” for CO2 – are under intense pressure for cultivation and logging, and undergoing rapid reduction in both area and density due to deforestation and habitat degradation. “Net deforestation has contributed between 22 - 44 per cent of the historical CO2 rise. Since 1980, global forest area has been reduced by approximately 2.2 million sq km. Current estimates of emissions attributed to deforestation are in the region of 5.9 gigatonnes of CO2 per year.”
She said future projections of deforestation by the UN’s Intergovermental Panel on Climate Change estimate a 15 to 29 per cent loss of tropical forests by 2050, leading to estimated emissions of 79 to 332 gigatonnes of CO2.
