The Ecosystem Services Unit of Winrock International (WI) and Woods Hole Research Center (WHRC) today announced they have reached scientific consensus on gross carbon dioxide (CO2) emissions from tropical deforestation. The analysis provides a crucial piece of information that now allows policymakers to confidently set targets for emissions reductions based on scientifically derived benchmarks.
The new consensus on CO2 emissions from gross tropical deforestation emerges from analysis of two independent peer-reviewed studies released by WI and WHRC earlier in 2012 in Science and Nature Climate Change, respectively. These two original studies (which were not coordinated) initially appeared to differ widely on the question of global gross emissions from tropical deforestation. But after the two research teams came together to discuss and investigate their individual findings, they discovered that the initial studies were remarkably consistent when disparities in data sets, methodologies and timeframes were factored out.
The analysis of the two original studies – released today by WI and WHRC and titled “Progress Toward a Consensus on Carbon Emissions from Tropical Deforestation” – concluded that when accounting for the same carbon pools and time frames, their initial studies actually agreed with each other that emissions from gross deforestation in tropical regions contributed about 3.0 Gigatons of CO2 per year to the atmosphere from 2000-2005.
“With this new scientific consensus and reconciliation between our two independent studies, policymakers now have an unbiased, historic benchmark against which emission reduction targets for tropical deforestation can be set and progress can be measured,” said Nancy Harris, lead author of the WI study and a Carbon and Land Use Specialist at WI.
Alessandro Baccini, lead author of the WHRC study and an Assistant Scientist at WHRC, said, “Both initial studies offer insights into different ways to measure tropical deforestation. But the fact that we were able to reconcile these different studies across very different sets of data and methodologies, should provide remarkable reassurance to policymakers that they can act with science on their side.”
Tropical deforestation and degradation are considered significant contributors to the greenhouse gases that cause climate change. Efforts to enact REDD+ (Reducing Emissions from Deforestation and Forest Degradation) policies and programs are aimed at ensuring retention of carbon stored in forests, forest conservation, sustainable management of forests and enhancement of forest carbon stocks, along with other initiatives.
The joint analysis notes that: “REDD+ negotiators within the United Nations Framework Convention on Climate Change (UNFCCC) have previously discussed, but thus far avoided, setting an explicit target for emission reductions. Other groups, including the European Commission, the Informal Working Group on Interim Finance for REDD+, and the UK government’s Eliasch Review, have converged around a target of cutting tropical deforestation by 50% by 2020, but the benchmark against which this target should be evaluated has been unclear. By achieving consensus within the scientific community that emissions from tropical deforestation between 2000 and 2005 were 3.0 ± 1.1 Gt CO2 yr-1 (0.8 ± 0.3 Pg C yr-1), researchers have given policymakers an unbiased, historic benchmark to use in discussing agreement on a target of reducing emissions from gross tropical deforestation to below 1.5 Gt CO2 yr-1 (0.4 Pg C yr-1) by 2020.”
The WI and WHRC analysis did not reach consensus on CO2 emissions outside of deforestation, such as forest degradation, shifting land-use, and emissions from mineral soils and peat. Both groups agree better data are needed to accurately quantify the atmospheric impacts of these components. These emissions alone could account for another 2.3 Gigatons of CO2 per year, allowing policymakers to include even more reductions from REDD+ should they choose to do so. However, the uncertainty around this estimate is significant and unquantified, the two groups noted.
“If policymakers prefer to use a more inclusive target by incorporating other emission sources important to REDD+ in addition to deforestation, then the 50% target increases to about 2.6 Gt CO2 yr-1 (0.7 Pg C yr-1) by 2020,” the analysis states.
The analysis was jointly funded by the Government of Norway’s International Climate and Forest Initiative (NICFI) and the Climate and Land Use Alliance (CLUA).