Deforestation in tropical regions currently continues apace, despite public outcries, the efforts of concerned groups, and media attention worldwide. The clearing of forests jeopardizes plans to cut back greenhouse gas emissions, conserve biodiversity in these areas and protect the valuable ecosystem services provided by tropical forests. Although there have been renewed commitments to reduce deforestation, made for example at the climate COP26 in 2021, the drivers of deforestation are poorly understood.
A new study published in the journal Science has reviewed the extent to which agricultural expansion drives deforestation in tropical regions. In the past, agriculture has been cited as driving 80 percent of deforestation, but the international team of researchers responsible for the current research say this figure is much higher.
“Our review makes clear that between 90 and 99 percent of all deforestation in the tropics is driven directly or indirectly by agriculture. But what surprised us was that a comparatively smaller share of the deforestation – between 45 and 65 percent – results in the expansion of actual agricultural production on the deforested land. This finding is of profound importance for designing effective measures to reduce deforestation and promote sustainable rural development,” said study lead author Florence Pendrill from Chalmers University of Technology, Sweden.
The review undertaken by the researchers focused on pantropical assessments of deforestation drivers in 87 tropical and subtropical countries covering most of Latin America, Africa south of the Sahara, and South and Southeast Asia. These data were combined with national-level estimates of deforestation in 11 of the countries with the highest rates of deforestation. Their focus was on the time period between 2011 and 2015.
The researchers record significant obstacles to determining rates of deforestation from the literature, mostly because previous studies use a diversity of methods to measure this and even to define what is meant by deforestation. The current researchers defined deforestation as “a persistent conversion of natural forest to any other land use, such as agriculture or human settlements, or to tree plantations,” and then reviewed studies from different sources to derive estimates of the rate of deforestation that were in line with their chosen definition.
The analysis revealed that between 6.4 and 8.8 million hectares (Mha) of tropical forest were cleared for agricultural and other use each year between 2011 and 2015. However, not all of this newly cleared land actually ended up being used for productive agriculture. The researchers report a discrepancy in the region of 2.0–4.5 Mha per year between forest cleared in the name of agriculture and the presence of newly created, active agricultural lands. This is consistent with previous regional and pantropical remote sensing studies that identify large tracts of unused land following forest clearance.
This discrepancy is present across all three continents considered in the study, and amounts to 1.0 to 2.0 Mha per year in Latin America, 0.0 to 1.3 Mha per year in Africa, and 1.1 to 1.2 Mha per year in Asia. The reasons why cleared forests are not converted into productive agricultural land include contested land claims, unsustainable practices like growing pasture for cattle on nutrient poor soils, and the unexpected collapse of markets. In addition, forest is often cleared for speculative purposes or to strengthen claims on uninhabited land, and is then subsequently abandoned.
“A big piece of the puzzle is just how much deforestation is ‘for nothing,’” observed Professor Patrick Meyfroidt from UCLouvain and F.R.S.-FNRS in Belgium. “While agriculture is the ultimate driver, forests and other ecosystems are often cleared for land speculation that never materialized, projects that were abandoned or ill-conceived, land that proved unsuitable for cultivation, as well as due to fires that spread into forests neighboring cleared areas.”
Newly deforested land that is used for agricultural purposes is most often used for pasture development and the rearing of cattle. In addition, only a handful of consumer commodities are responsible for the majority of deforestation linked to actively producing agricultural land – these include soy, palm oil and rubber, as well as coffee, cocoa, rice, maize and cassava. Recent initiatives to halt deforestation have called for a ban on such produce that is cultivated on deforested land.
“Sector specific initiatives to combat deforestation can be invaluable, and new measures to prohibit imports of commodities linked to deforestation in consumer markets, such as those under negotiation in the EU, UK and USA represent a major step forward from largely voluntary efforts to combat deforestation to date,” said Dr. Toby Gardner of the Stockholm Environment Institute and Director of the supply chain transparency initiative, Trase.
“But as our study shows, strengthening forest and land-use governance in producer countries has to be the ultimate goal of any policy response. Supply chain and demand-side measures must be designed in a way that also tackles the underlying and indirect ways in which agriculture is linked to deforestation. They need to drive improvements in sustainable rural development, otherwise we can expect to see deforestation rates remaining stubbornly high in many places,” Dr. Gardner added.
The study’s findings point to the need for supply chain interventions to go beyond a focus on specific commodities and risk management, to help drive genuine partnerships between producer and consumer markets and governments. This needs to include strong incentive-based measures that make sustainable agriculture economically attractive, while disincentivizing further conversion of native vegetation and supporting the most vulnerable smallholder farmers. The authors say this should include a stronger focus on domestic markets, often the biggest drivers of demand for many commodities, including beef, and a strengthening of partnerships between companies, governments and civil society in producer jurisdictions.
Finally, the study highlights three critical gaps where a stronger evidence base is needed to better target efforts to reduce deforestation; “The first is that without a globally and temporally consistent data product on deforestation we cannot be confident about overall trends in conversion. The second is that except for oil palm and soy, we lack data on the coverage and expansion of specific commodities to know which are more important, with our understanding of global pasture and grazing lands being especially dire. The third is that we know comparatively very little indeed about tropical dry forests, and forests in Africa,” said Professor Martin Persson of Chalmers University of Technology.
“What is most worrying, given the urgency of the crisis is that each of these evidence gaps poses significant barriers to our ability to drive down deforestation in the most effective way – by knowing where the problems are concentrated, and understanding the success of efforts to date,” said Professor Persson.
Despite these knowledge gaps and remaining uncertainties, the study stresses that a step-change in efforts is urgently needed to effectively tackle and curb deforestation and conversion of other ecosystems and to foster sustainable rural development. The Glasgow Declaration on Forests recognized the importance of jointly addressing the crises of climate and biodiversity loss and set a new level of ambition for tackling deforestation and promoting sustainable agriculture. The authors of this new study say it is paramount that we begin to see individual countries and policymakers prioritize the realization of this ambition.
By Alison Bosman, Earth.com Staff Writer