Deforestation of tropical forests is one of the main drivers of the climate crisis. Behind many clearings are farms. A new study shows that this influence is even greater than previously thought. Many deforested areas are then not used at all.
Agriculture contributes much more to the deforestation of tropical forests than previously assumed. According to analyzes by an international research team, 90 to 99 percent of deforestation in these areas is directly or indirectly attributable to agriculture. Surprisingly, only 45 to 65 percent of the cleared areas are actively used for agriculture immediately afterwards, as reported by Florence Pendrill's team from Chalmers University of Technology in Gothenburg in the journal Science.
The ongoing large-scale clearing of tropical forests is considered one of the greatest environmental problems on the planet: it is accompanied by greenhouse gas emissions, destroying unique ecosystems and reducing biodiversity. It is undisputed that deforestation in the tropics is mainly due to agriculture. However, the extent of this involvement was unclear. So far, observers assumed the figure was around 80 percent - albeit without a reliable database.
Pendrill's team tested this by comparing different data sets for the period from 2011 to 2015 for 87 tropical and subtropical countries. Sources included data from the Food and Agriculture Organization (FAO) and information from Global Forest Change (GFC), which is based on annual remote sensing data.
The areas are mostly used as pastures or for agriculture: "The expansion of cattle pastures is by far the most important factor, which accounts for about half of the deforestation in the tropics cleared for agricultural purposes," says the study. Palm oil and soy plantations account for at least another 20 percent. The remaining area is mainly used for six crops: rubber, cocoa, coffee, rice, corn and cassava.
It is not only the extreme participation of agriculture in the clearing that is surprising. In addition, only 45 to 65 percent of these areas - i.e. 2.0 to 4.5 million hectares - are actively used for agriculture immediately after clearing. The other areas are currently idle, sometimes for years. This applies to varying degrees in Latin America as well as in Africa and Asia.
The researchers attribute this to the fact that areas are often cut down as a precautionary measure when there is a good opportunity - for example for land speculation, in anticipation of better infrastructure in the future, for example through the construction of roads or before stricter environmental laws come into force. The ownership of cleared areas is often unclear or the land is simply unsuitable for agricultural use. In addition, intentionally set fires that are intended to clear a certain area could spread uncontrolled to adjacent forest areas.
From the findings, the team derives recommendations to slow down the extent of deforestation. "Our study shows that the ultimate goal of a policy response must be more regulation of forest and land use in producer countries," says co-author Toby Gardner of the Stockholm Environment Institute.
Although crops such as soy, palm oil, cocoa and coffee are mostly traded internationally, most of the products produced on the cleared areas end up on the domestic markets. It is therefore important to promote sustainable development in rural regions, also with regard to smallholders.