- Agriculture is the primary driver of tropical deforestation, accounting for 90% or more of forest loss, yet researchers have found that up to half of total land cleared is not put into active agricultural production.
- The gap between what’s cleared and what’s used for agriculture shows that “we have to fix agriculture and we have to fix deforestation,” according to one of the researchers.
- Tropical deforestation is a major contributor to global greenhouse gas emissions and climate change, but the research shows there is no simple fix, as humanity’s increasing food needs coincide with the need for conservation.
Agriculture is gradually killing forests, and yet up to half of tropical forestland in Africa, Latin America and Asia cleared for agriculture remains idle, according to research published in the journal Science. The literature review, which analyzes a range of pantropical studies of deforestation, estimates that between 6.4 million and 8.8 million hectares (15.8 million and 21.7 million acres) of tropical forests are lost to agriculture annually. For perspective, on the low end, this is the equivalent of more than 8 million soccer fields, or more than three times the size of Rwanda.
This has huge implications. Humanity depends on forests for uncountable resources. Forests are a rich harbor for biodiversity and also a major carbon sink, storing carbon dioxide from the atmosphere that is linked to climate change.
“[Deforestation] releases a lot of carbon that contributes to global warming, which is threatening communities all over the world; it contributes to loss of biodiversity [and] also affects local climate leading to reduction in rainfall,” says Martin Persson, an associate professor at Chalmers University of Technology in Sweden and a co-author of the research. He adds that research in Brazil shows large-scale deforestation for soy cultivation results in localized climate effects that reduce soy yields. Furthermore, loss of trees can result in soil degradation and erosion.
According to the Science paper, which includes analysis of studies in Africa, Latin America and Asia, 90-99% of forest loss can be attributed to agriculture, either directly through clearing of forests for agricultural expansion or indirectly through loss of forest as a result of agriculture-related activities. Research shows that clearance for pastures accounts for about half of the deforestation, translating to between 1.9 million hectares and 2.7 million hectares (4.7-6.7 million acres) of forest per year.
The research, based on data from 2011 to 2015, also finds that only about a third to half of all land cleared for agriculture is put into productive use.
“It is not surprising that agriculture is the main driver [of deforestation], what was more surprising was the fact that between one-third and one-half of the land that is being converted is not going into active production,” says Toby Gardner, a senior research fellow at Stockholm Environment Institute and co-author of the research.
This huge gap between forestland cleared for agriculture and the acreage actually used for agriculture is the greatest cause for concern, says Patrick Meyfroidt, a co-author of the study and professor of geography at the Catholic University of Louvain in Belgium.
He says that conflicts over land ownership, allocation and use are some of the key reasons cleared land goes unused.
“Some of these lands are land that is cleared and then there is a conflict of tenure; so one farmer decides to clear the land to use it and then another farmer claims the land … and because of the conflict, nobody uses the land,” Meyfroidt says. He adds that in other cases, farmers clear land only to realize that it is not favorable for the crops they intend to grow and they end up abandoning the land. In still other cases, it is due to lack of capital or markets for cultivated crops.
According to Persson, while the team’s findings are significant, lack of a concrete tropical forest-cover mapping system hinders efforts to curb deforestation.
“One problem we point out is that we can’t definitely say whether deforestation is increasing or decreasing in the tropics, and as long as we can’t say that, it’s also hard to evaluate the measures that have been taken to reduce deforestation,” Persson says.
The Science research identifies particular crops that pose the greatest risk to forests. Soy and palm oil account for a fifth of forest loss, while other crops, including cocoa, rubber, coffee, rice, maize and cassava, share the remainder. The loss attributed to each crop varies with region.
Meyfroidt says that even when agriculture does not directly result in deforestation, it still is indirectly a cause — for instance, when trees are felled to establish roads into plantations and to build farm structures.
“Agriculture is crucial, and even in places where people depend a lot on forests, they would still depend more on agriculture than from the forests,” Meyfroidt says. “But I think in many situations, it is not that there is a hard trade-off to make … indeed there is a large share of deforestation that is currently not resulting in productive use, so this could be restricted and eliminated. The basic implication is that we have to fix agriculture and we have to fix deforestation.”
Although agriculture is vital to human survival, the research shows that it is also a major contributor to deforestation and consequently further risk of climate disasters. If agriculture in its current forms is left unchecked, it could contribute to catastrophic climatic results in the future.
A 2014 NASA-led study shows that tropical forests absorb an estimated 1.4 billion metric tons of carbon dioxide out of a total 2.5 billion metric tons global absorption. Carbon dioxide is the leading greenhouse gas, accounting for 76% of all global greenhouse gas emissions, according to the United States Environmental Protection Agency. What this means is that the loss of tropical forests directly contributes to climate change and the resultant consequences.
The Kenya example
While scientists are gaining greater understanding of the harms of agriculture and destruction of forests, there is no simple solution. Kenya offers an example that shows the complexity of the problem.
In Kenya, the nexus between agriculture and forest conservation is nuanced, and the topic often raises controversy. This was shown in the evictions of more than 50,000 people from the Mau Forest complex in the past decade, ostensibly over forest degradation resulting from human activities. The Mau Forest is an important water tower and was declared a forest reserve in the 1950s.
While available data show an increase in forest cover in Kenya from 3.5 million hectares (8.6 million acres) in 2015 to 3.6 million hectares (8.9 million acres) in 2020, forest encroachment still remains a threat. Kenya’s President William Ruto highlighted this in his Oct. 20 speech during the Mashujaa Day (Heroes Day) celebrations, when he reaffirmed his commitment to increase the country’s tree cover from the current 12% to more than 30% by 2032.
“The central role forests play in addressing the effects of climate change has become more prominent now than ever, thanks to the unparalleled capacity to absorb, store carbon and regulate climate,” the president said.
However, with agriculture accounting for at least 22% of Kenya’s economy, it is unlikely that forest conservation may take precedence over agriculture. This means that communities, for instance those in the Mau Forest, may continue to expand into forests for the sake of agriculture.
Timothy Njagi, a researcher at the Tegemeo Institute of Agricultural Policy and Development at Egerton University, says that in the context of Kenya, it boils down to a matter of choice between food and forests.
“It is basically survival — people need food,” says Njagi. He refers to the “shamba system” in which farmers were allowed to cultivate crops in degraded forests while tending to the trees. They then moved out once the trees matured. The system, formally known as the Plantation Establishment for Livelihood Improvement Scheme, or PELIS, was first practiced in Kenya in the early 1900s and later abolished and reinstated multiple times. Most recently, it was banned around 2003, as farmers would encroach on the forests, contributing to the degradation the system was meant to solve.
“That is why in Kenya right now you have heard the debate about going back to the shamba system; it is because they are trying to address a food security problem because people don’t have enough,” Njagi adds, referring to remarks by Kenya’s deputy president about reintroducing the system, which have been met by a lot of criticism.
He explains that the hard choice between human food needs and forest conservation may drive the deforestation trends described in the Science research. This resonates with the finding that expansion for agriculture is fostered by the ever-increasing domestic and international demand for food, with international demand accounting for just a quarter of the overall.
“With the effects of climate change that we are experiencing right now, we have to see how to balance, and that means that one of the best options would be to try and increase productivity so that you can get more from the available land,” Njagi says. He adds that due to land degradation over time, an acre of land, for instance, gradually decreases in productivity, resulting in a burgeoning need for larger tracts of land to maintain expected crop outputs.
Njagi recommends efforts to regenerate Indigenous forests to counter deforestation as well as the adoption of agroforestry, which is defined by the U.S. Department of Agriculture as “the intentional integration of trees and shrubs into crop and animal farming systems to create environmental, economic and social benefits.”
Persson says that despite the appearance of a grim trend, not all hope is lost.
“It might be easier to reduce the deforestation than you otherwise would have thought because if a lot of the deforestation, a large share that is driven by agriculture, is for no good use, it is not necessarily a clear trade-off between deforestation and feeding a growing population — we can do both,” he says.
He adds that improved forest-monitoring systems can be used in formulating appropriate policies with accurate data. He also recommends concerted efforts by local and national governments, especially in implementing zoning plans to ensure forests are not lost extensively to agriculture.
In addition, agricultural corporations driving deforestation through dealing in forest risk commodities have a responsibility to counter excessive forest loss, Persson says.
But the responsibility of easing deforestation goes beyond corporations, he adds. Persson says a mix of individual efforts, improved land tenure policies, agricultural extension services and financial support for farmers would go a long way to alleviate extensive forest loss.
“It must be a combination [of efforts] from companies, corporations that are contributing to deforestation through the trade in commodities like soybeans or palm oil or coffee,” he says. “Sometimes that trade-off is clearer when it comes to deforestation driven by smallholder and subsistence farmers, but in other cases it’s about profits.”
Banner image: Deforestation in Borneo, Malaysia. Image by Rhett A. Butler/Mongabay.
Citations:
Pendrill, F., Gardner, T. A., Meyfroidt, P., Persson, U. M., Adams, J., Azevedo, T., … West, C. (2022). Disentangling the numbers behind agriculture-driven tropical deforestation. Science, 377(6611). doi:10.1126/science.abm9267
Pendrill, F., Persson, U. M., Godar, J., Kastner, T., Moran, D., Schmidt, S., & Wood, R. (2019). Agricultural and forestry trade drives large share of tropical deforestation emissions. Global Environmental Change, 56, 1-10. doi:10.1016/j.gloenvcha.2019.03.002
Goldman, E., Weisse, M., Harris, N., & Schneider, M. (2020). Estimating the Role of Seven Commodities in Agriculture-Linked Deforestation: Oil Palm, Soy, Cattle, Wood Fiber, Cocoa, Coffee, and Rubber. doi:10.46830/writn.na.00001