How much has reducing deforestation contributed to mitigating climate change?

Background/Question/Methods

Reducing tropical deforestation, which is responsible for about 15% of greenhouse gas emissions, has been identified as one of the most promising ways to mitigate global warming. This has been the basis for international and national programs for REDD+ (Reducing Emissions from Deforestation and Forest Degradation, plus related pro-forest actions). There has now been considerable success in some of these programs.

The goal of this study was to estimate how much recent reductions in deforestation have contributed to mitigating climate change, both in absolute terms and relative to energy-sector efforts. It used both global data sources (Global Carbon Project 2010, FAO’s Global Forest Resources Assessment 2010, Hansen et al. 2010, PNAS, and the Chatham House (2010) assessment of reduction in illegal logging) and estimates for the major tropical deforesting countries (Brazil: INPE and IMAZON 2010 estimates; Indonesia:  Hansen et al. 2009 Env. Res. Letters and FORMA 2010).

Results/Conclusions

Reductions in deforestation over the past decade have reduced global greenhouse gas emissions by somewhat more than 1.5 GtCO₂. This represents a drop in deforestation emissions of between 30% and 42%, depending on the baseline year or years used. It is by far the largest contribution of any sector to reducing global warming pollution.

Brazil, which has reduced deforestation by 2/3 over the past 6 years, can claim credit for between 50% and 60% of the total reduction, although Indonesia and other countries have also made appreciable contributions. In fact, Brazil’s reduction since 2004-2005 is comparable to the European Union’s pledge  of the reductions it will make through 2020 (a 20% cut from its 1990 level), and not far below the U.S.’ pledge for 2020 (a 17% cut from its 2005 level).

The reduction is due to a number of factors, including the success of bilateral REDD+ programs (most notably, Brazil’s agreement with Norway). It is not due to the global recession which began in 2008, and in fact has occurred despite a large spike in prices for soybeans and other agricultural commodities that are the principal drivers of deforestation.  So far, tropical forest developing countries have contributed much more toward mitigating climate change than have the wealthy industrialized countries.