An increased influx of people into urban areas and large export-driven agriculture is responsible for recent deforestation in the tropics, scientists say in Nature Geoscience.

Kuala Lumpur, Malaysia. Photo: Tom Hermansson - Snickars. Azote.se

Arguably the only positive outcome from COP15 in Copenhagen was the broad support toward the REDD-plus initiative. REDD-plus (Reduced Emissions from Deforestation and forest Degradation) is essentially a set of steps designed to use market/financial incentives to reduce greenhouse gas emissions from deforestation (which today stands for around 20% of total human emissions). However the success of such initiatives hinges on whether they succesfully address and target the underlying factors causing deforestation.

This has been the cause of some debate among researchers. One line of thinking suggests that people in rural areas are driving the clear-cutting and that a shift toward increased urbanization will alleviate the problem, whereas other researchers implicate large-scale agriculture as the primary driver of forest loss. A team of U.S scientists tackled this unresolved question by investigating which economic, demographic and agricultural factors could best explain deforestation occuring between 2000-2005 in 41 tropical nations.

The team reports that deforestation was closely tied to increases in urban populations and demands in agricultural products in distant and international locations. In contrast, changes in rural populations didn’t have much of an effect on patterns of forest loss. Comparing these results with other, older studies, provides some interesting insights. Previous analyses have generally found deforestation to be positively associated with rural growth rates and negatively associated with urban growth rates for the 1980s and 1990s, suggesting that rural to urban migration reduced pressure on forests in this time period. But today, the authors of this study argue, the relationship seems to have been reversed and the steady increase in city-dwellers appears to be boosting demand for meat and processed food. Since urban populations are expected to continue growing, the pressure on forests could become even more intense in the future, the authors say. Initiatives such as REDD need to recognize that drivers of deforestation seem to shift over time and require policies that can increase agricultural production (in light of increased demand) on already cleared lands.