The rainforest plays a crucial role in regulating the global climate. By storing carbon, the rainforest helps to mitigate the effects of climate change. If rainforest is destroyed, it loses its important function as a global CO2 store. Every ton of CO2 emitted causes damage through further warming. Higher temperatures lead to rising sea levels, more frequent weather extremes and increased health problems. All of this can lead to property and infrastructure damage, as well as agricultural yield and crop losses. The research team led by Thomas Knoke, Professor of Forest Inventory and Sustainable Use at TUM, and Carola Paul, Professor of Forest Economics and Land Use Planning at the University of Göttingen and TUM alumna, has published a new approach for determining the economic value of avoided deforestation through rainforest conservation measures in the journal Nature Sustainability.
You can only assess what you can measure
The international community is intensively discussing how to reduce forest losses. However, it is not easy to assess whether previous forest protection measures, such as legislative changes and stricter controls on compliance with forest protection measures, have been effective at all. One needs a reference scenario that maps expected forest losses without the influence of forest protection measures. While such references have so far been derived from statistical models, the research team has for the first time conducted a simulation of deforestation decisions based on market signals, i.e. reflecting purely economic interests.
Political rules and goals influence rainforest loss
Different simulated agricultural decisions in Brazil, the Democratic Republic of Congo and Indonesia resulted in an independent reference scenario. By comparison with actually observed forest loss based on analysed satellite data, clear trends in tropical forest loss emerged in the countries considered. In relation to the reference scenario, at times significantly less rainforest loss could be detected after legislative changes for forest protection (Brazil) and stricter controls (Indonesia), but also increased forest loss after election promises (Indonesia) or during armed conflicts (Democratic Republic of Congo).
Climate regulation by tropical forest has high social value
If rainforest is destroyed, this releases CO2. The CO2 that remains in the atmosphere for a very long time is a driver of further global warming. The future damage associated with CO2 emissions is called the social cost of carbon. Avoided forest losses reduce social costs and thus represent a social value. In the new computational model, saved and additional emissions from changes in rainforest loss are considered. The mathematical models processed data from 2000 to 2019. Because reductions in forest loss occurred temporally before increased forest loss, the researchers were able to demonstrate a high social value of temporarily reduced deforestation using their dynamic valuation method. The results clearly showed that avoided losses are always valuable, even if there is a future risk of loss to the forest and its carbon.
Forest conservation is economically valuable
"In our model, we assess the social economic value of temporary reductions in forest loss in Brazil and Indonesia at 92.2 billion euros," explains Prof. Knoke. "Forest conservation measures, even those with a more short-term effect, always have a positive economic value. Every ton of CO2 sequestered by tropical trees mitigates the effects of climate change and reduces economic damages in the future."
Prof. Paul highlights the positive effects of rainforest protection:
"Temporary successes in forest protection are of course not sufficient in the long run. However, our study is encouraging in that any protection of tropical forests is also economically valuable. Remarkably, the social value of climate regulation through forest protection exceeds the private economic benefits of forest clearing."
Publication: „Trends in tropical forest loss and the social value of emission reductions“; Thomas Knoke, Nick Hanley, Rosa Maria Roman-Cuesta, Ben Groom, Frank Venmans & Carola Paul: https://www.nature.com/articles/s41893-023-01175-9
Scientific contact:
Prof. Dr. Thomas Knoke
TUM School of Life Sciences
Institute of Forest Management
knoke(at)tum.de
Editing:
Dagmar Wagner
TUM Corporate Communication Center
Press and Public Relations