In the late 1980s, the first publications on the harmful impacts of climate change appeared in health journals (1). Until then, the potentially catastrophic consequences from human induced environmental degradation and “planetary overload” had been poorly recognised by the medical establishment. Only two decades later, though, climate change was described as the “biggest global health threat of the 21st century” (2) and over the last decade we have seen an exponential increase in the literature, reflecting not only the escalating severity of the issue, but also a growing awareness of the devastating health risks from climate change. It hopefully also reflects an upsurge in the collective understanding of the inherent link between healthy ecosystems and healthy people.
The concept of ecosystem services (3) provides a framework for understanding human beings’ fundamental dependence on biodiverse and functioning ecosystems. Ecosystem services provide, for example, food, timber and other necessities for survival, but also contribute to climate regulation, water quality, cultural experiences, and other key constituents of human health and wellbeing.
Ecosystem services are integrated in the relatively recent concept of nature-based solutions (NbS), a concept that is now incorporated in key intergovernmental agreements across Europe. The International Union for Conservation of Nature defines NbS as “actions to protect, sustainably manage, and restore natural and modified ecosystems that address societal challenges effectively and adaptively, simultaneously benefiting people and nature”. NbS can provide one third of the climate mitigation needed to meet the goals of the Paris Agreement, according to recent estimates (4).
European forests play a key role in climate change mitigation by sequestering and storing carbon (in combination called carbon sink) and represent a critical NbS. Forests remove CO2 from the atmosphere through photosynthesis and emit it back via decomposition and combustion. Different management strategies influence this balance and the relative carbon sink.
Currently, the European forests mitigate around 10% of EU-27’s total annual GHG emissions. The European Forest Institute estimates that this could be increased by 40% using combined strategies of forest conservation, decreased harvesting, and adapted management methods. The results would approach the EU policy target for CO2 removal by the Land Use, Land-use Change and Forestry (LULUCF) sector by 2050.
Beyond their role as carbon sinks, forests have the potential to deliver numerous human health benefits. These benefits have typically been attributed to various mediating variables, such as recreation, physical activity, stress relief, and social interactions. Several studies have also analysed health impacts from regulating pathways and services, including reduction of heat, noise, and air pollution with reduced mortality as a result. Systematic reviews have concluded that through these pathways direct health benefits, such as improved mental health and reduced prevalence of cardiovascular illness, respiratory diseases, diabetes, depression, cancer, and dementia, can be obtained. Some studies also indicate that exposure to biodiverse microorganisms in nature has a positive impact on the human gut microbiome, leading to improved immunoregulation.
However, the current understanding of synergies between forest-based climate change mitigation and health and wellbeing is insufficient. Within CATALYSE, we pursued an exploration of the related research landscape and to what extent the interdisciplinary nexus between forests as carbon sinks and human health co-benefits has been addressed. While the area is clearly under-studied, we did identify potential synergies between management principles that optimise carbon sink capacity and simultaneously have significant, positive impacts on mediating pathways and health. In general, we can expect negative impacts on both climate change mitigation and human health from deforestation and clear-cutting strategies, while species diversity, tree cover increase, and recreation management seem to improve both carbon sink capacity and health benefits.
As we grapple with the urgent need to address climate change, it’s encouraging to discover that the nature-based solutions we intend to apply can also nurture health and well-being. Forest-based climate change mitigation not only contributes to a healthier planet but can also bring about tangible benefits to human health. By recognizing and harnessing the salutogenic power of the earth’s forests, we can embark on a journey towards a more sustainable and healthier future for coming generations and the ecosystems on which they depend.
REFERENCES
- Leaf A. Potential health effects of global climatic and environmental changes. N Engl J Med. 1989;321(23):1577-1583.
- Costello A, Abbas M, Allen A, et al. Managing the health effects of climate change. The Lancet. 2009;373(9676):1693-1733.
- MEA. Ecosystems and human well-being: Synthesis. Millenium Ecosystem Assessment. Washington DC2005.
- Miles LA, Raquel; Sengupta, Sandeep; Vidal, Adriana; Dickson, Barney. Nature-based solutions for climate change mitigation. Nairobi, Gland: United Nations Environment Programme and International Union for Conservation of Nature 2021.
