Protection of the rainforest also economically valuable

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Deforestation of rainforests not only leads to the loss of biodiversity, but als
Deforestation of rainforests not only leads to the loss of biodiversity, but also to high social costs. Photo: Thomas Knoke
Researchers compare real forest losses with simulated agricultural decisions

The destruction of the rainforest means not only loss of biodiversity, but also high social costs due to the release of greenhouse gases. Tropical forests sequester carbon from the atmosphere, helping to regulate the global climate. Loss of tree cover to agricultural activities releases CO2, accelerating climate change. An international research team led by the Technical University of Munich (TUM) and with participation from the University of Göttingen has used a new approach to quantify changes in forest loss and determine their economic impact. The conclusion: previous rainforest protection measures have a great economic value and save the global community billions of euros. The results have been published in the journal Nature Sustainability.

The international community is intensively discussing how to reduce forest losses. However, it is difficult to assess whether previous forest protection measures such as legislative changes have been effective. For comparison, a reference line is needed that represents expected forest losses without the influence of forest protection measures. Until now, such references have been derived from statistical models. But now, for the first time, researchers conducted a simulation of deforestation decisions based purely on economic interests. In doing so, simulated agricultural decisions in Brazil, the Democratic Republic (DR) of Congo and Indonesia led to an independent reference line. They compared this with actual forest losses determined from satellite data. Clear trends emerged: in relation to the reference value, there was at times significantly less forest loss following legislative changes to forest protection (Brazil) and stricter controls (Indonesia), but also increased forest loss following election promises (Indonesia) and during armed conflicts (DR Congo).

The new calculation model also takes into account saved and additional CO2 emissions. The gas is a driver of further global warming. This leads to rising sea levels, more frequent weather extremes, and health problems, which in turn can result in property and infrastructure damage, as well as agricultural yield and crop losses. Estimated future damages are considered the social cost of carbon. Avoided forest losses reduce these costs and thus represent a social value. The researchers processed data from 2000 to 2019 in their mathematical models. Because avoided forest losses in Brazil and Indonesia preceded increased forest losses in Indonesia and DR Congo in time, the researchers were able to demonstrate a high social value of reduced deforestation using their dynamic valuation method. It showed that avoided damage is always valuable, even if there is a future risk of loss to the forest.

-We put the social value of the temporary reductions in forest loss in Brazil and Indonesia in our model at 92.2 billion euros,- explains Thomas Knoke from the Forest Inventory and Sustainable Use department at TUM. -Forest protection measures, even those with a rather short-term effect, always have an economic value. Every ton of CO2 sequestered by tropical trees mitigates the effects of climate change and reduces economic damages in the future.-.

Carola Paul from the Department of Forest Economics and Sustainable Land Use Planning at the University of Göttingen highlights the positive effects of rainforest protection: -Temporarily limited successes in forest protection are of course not sufficient in the long run. However, our study is encouraging in that any protection of tropical forest is also economically valuable. Remarkably, the social value of climate regulation through forest protection exceeds the private economic benefits of forest clearing.-.

Original publication: Thomas Knoke et al. Trends in tropical forest loss and the social value of emission reductions. Nature Sustainability (2023). DOI: 10.1038/s41893’023 -01175-9