Tropical deforestation is causing significant reductions in local rainfall, according to a peer-reviewed study published in Nature in March 2023. Conducted across all three major tropical forest regions, the study shows large reductions in precipitation even for relatively small amounts of forest loss. It estimates that future deforestation in the Congo Basin will reduce local rainfall by 8-10 per cent by the end of the century.
These estimates are conservative: they do not take into account the effects of climate change – such as increased heat and droughts – that will dramatically reduce rainfall.
Paradoxically, most of this deforestation is being caused by agriculture, and in the end it will be agriculture that suffers. The Nature study finds that, on average, crop yields decline by 0.5 per cent for each percentage point reduction of precipitation. This means that further agricultural expansion in tropical forest regions could actually decrease overall production, as the lack of rain may outweigh any benefits from increasing cropland.
Although the study only looked at the Amazon, the Congo Basin and Southeast Asia, similar effects can already be observed in West Africa, where the southern coastal regions have already lost most of the tropical forest. The production of cocoa – which is mostly consumed in Europe – has been a major driver of this deforestation, particularly in Côte d’Ivoire and Ghana.
Cocoa production is now already suffering from the impacts of this deforestation. A 2017 study found that 95.5 per cent heads of household in one of Côte d’Ivoire’s major cocoa production areas have observed a changing climate: specifically, a shift in the rainy season and dry season pattern (timing, length and intensity).
Cocoa grows only under very specific conditions, requiring high levels of precipitation and humidity. Reduced precipitation therefore poses an existential threat to cocoa production in West Africa, exacerbated by the temperature increases brought on by climate change: the International Center for Tropical Agriculture (CIAT) found that expected temperature increases will drastically reduce the amount of land suitable for cocoa production.
This is critical information for those with the power to act in tropical forest countries’ agricultural sectors, be they multinational companies or those countries’ governments. The drive to produce more, if it involves clearing forest to create new cropland, could backfire badly.
Agriculture in tropical countries is already highly vulnerable to increased temperatures brought on by climate change. Preserving what remains of primary forest will be crucial to shield agriculture and farmers from these dangers; destroying it will make a very risky situation even riskier.
Category: Forest Watch