Carbon released through deforestation and forest degradation is the world’s second largest source of greenhouse gas emissions (estimated between 12% and 20% of global emissions), with much of that occurring in the tropics.
In addition to incentive mechanisms like REDD (Reduced Emissions from Deforestation and Forest Degradation), protected areas can play a significant role in promoting climate change mitigation.
To assess that role, a recent study examines the effect that 595 protected areas in the Brazilian Amazon have exerted on local deforestation rates.
These protected areas, encompassing 1.9 million km2 and 54% of the Brazilian Amazon’s remaining forests, can be divided into four main categories: strictly protected, sustainable use, indigenous land, and military reserves.
The authors conduct the analysis with a metric called the “odds ratio of deforestation”, which accounts for differences in probability of deforestation in areas used for pairwise comparison. For each protected area, the metric was applied to adjacent 10-km zones--one zone within the area and one outside of it.
From 1997 to 2008, three of the four categories (strictly protected, sustainable use, indigenous land) demonstrated an inhibitory effect on deforestation since being designated as protected. Considering the 206 protected areas established since 1999, 115 of them showed lower levels of deforestation relative to the unprotected comparison zone.
Deforestation in the Brazilian Amazon has declined steeply in recent years. To explain this trend, additional analysis found that 37% of the drop was due to new protected areas, while 44% owed to the decreased profitability of agriculture and ranching.
A common critique of measures protecting forests is that they are subject to leakage; this means that the deforestation avoided is displaced elsewhere, thereby reducing the net effect of the protection.
Investigating the potential for local leakage caused by designating protected areas, the study found no evidence for increased forest clearing by displaced local people or by emigrant land-grabbers in the vicinity around the protected areas. This indicates that protected areas may not only be successful at averting local deforestation, but also at influencing regional deforestation rates by deterring illegal land-grabbers.
One caveat is that this approach does not account for market leakage in more distant locations, which may occur when forest or agricultural products supplied decline due to forest protection actions and consequently producers elsewhere clear forests to grow more and satisfy unmet demand for those products.
By projecting the effect of fully implemented protected areas into the future, the study shows that they have the potential to avoid 8.0 (+/- 2.8) petagrams of carbon emissions by 2050. This amount is equal to 8 billion metric tons of carbon or over 4 years of greenhouse gas emissions produced by the U.S.
Not surprisingly, this system of protected areas in the Brazilian Amazon will not come cheap, involving both the opportunity costs of foregone profits of forest conversion as well as the costs of managing the areas. These are estimated to be about $150 billion in present value, though this could be paid for in part by international funds targeted to slow deforestation in tropical countries.
While these costs may seem substantial, weighing them against the global benefit of climate stabilization plus other co-benefits of forest protection such as biodiversity conservation, it seems like an investment with an attractive long-term return.
--Aaron Jenkins is a research associate with the Nicholas Institute for Environmental Policy Solutions at Duke University and a guest contributor to Conservation Maven.
Soares-Filho, B., Moutinho, P., Nepstad, D., Anderson, A., Rodrigues, H., Garcia, R., Dietzsch, L., Merry, F., Bowman, M., Hissa, L., Silvestrini, R., & Maretti, C. (2010). Role of Brazilian Amazon protected areas in climate change mitigation Proceedings of the National Academy of Sciences, 107 (24), 10821-10826 DOI: 10.1073/pnas.0913048107