New Research Suggests that Planting Trees Alone Cannot Stop Climate Change

14.08.2025

The challenge of climate change cannot be solved by simple measures such as planting trees. Restoring natural terrestrial habitats removes far less carbon dioxide from the atmosphere than earlier models suggested, according to a recent study. The researchers emphasise that the most urgent priority is to reduce emissions as rapidly as possible and to implement climate strategies that are equitable and that genuinely help societies adapt to the consequences of climate change.

The European Union’s new Nature Restoration Law, adopted last year, is the EU’s response to the biodiversity crisis. Under this ambitious programme, one-fifth of all terrestrial and marine areas in the EU are to be restored by 2030, and all degraded habitats by 2050. The aim is not only to protect species and their habitats but also to mitigate climate change through natural carbon sequestration.

According to a recent international study, however, focusing solely on carbon sequestration is not sufficient. Ákos Bede-Fazekas, a researcher at the HUN-REN Centre for Ecological Research and a lead author of the study, emphasises that policymakers need to adopt a holistic approach when considering ecosystem restoration: the focus should be on biodiversity and on nature’s contributions to people, rather than on carbon sequestration alone.

Over the past decade, habitat restoration has increasingly been viewed by society as a tool for mitigating climate change – a key element in addressing both the climate and biodiversity crises. It is often claimed that restoring habitats could offset a significant proportion of human carbon dioxide emissions. However, ecosystem restoration is a more complex process than simply creating semi-natural forests or tree plantations.

“Earlier models overestimated the potential of afforestation, overlooking non-forest habitats, the risk of biodiversity loss and water scarcity,” said Nándor Csikós, a researcher at the Department of Soil Mapping and Environmental Informatics of the Institute for Soil Sciences at the HUN-REN Centre For Agricultural Research (HUN-REN CAR), and one of the study’s lead authors.

According to the researcher, more recent models examine a broader range of ecosystems and provide more accurate estimates by taking into account local climate, soil characteristics and the pace of implementation. These models are already much closer to reality than the earlier ones.

The international research team was led by Csaba Tölgyesi, a researcher at the University of Szeged, who stressed that modelling carbon sequestration requires an approach that takes all possible natural ecosystem types into account.

The findings of the international study published in Nature Geoscience revealed surprisingly large discrepancies. The study showed that, under most scenarios, ecosystem restoration reduces atmospheric carbon dioxide levels only marginally. Even in the most optimistic – or ‘greenest’ – scenario, at most 17% of human emissions could be sequestered by 2100, whereas if current trends continue, this share falls below 4%.

According to the researchers, projections from models of climate change mitigation through ecosystem restoration indicate that a policy shift is urgently needed to achieve the transition to a low-carbon economy.

Caroline Lehmann, a co-author of the study and a researcher at the Royal Botanic Garden Edinburgh, added: “Given the limited likelihood of global ecosystem restoration substantially mitigating climate change in the short to medium term, restoration activities should be prioritised to benefit vulnerable communities and biodiversity, in order to support the resilience of both nature and humanity in the face of climate change.”