PLANTING trees will not fix climate change, according to a new report.
The research, published in the Nature Geosciences journal, shows tree planting is not an effective way to reduce carbon in the atmosphere.
Instead, the focus needs to be on rapidly reducing emissions while ensuring initiatives are “equitable” and centred on climate change adaptation.
The report comes as concern grows over the amount of public money given to private companies and landowners to plant trees for “carbon offsetting” in Scotland.
In the last decade, habitat restoration, often narrowed down to tree-planting, has been increasingly used as a means for climate change mitigation, a key element in response to both the climate crisis and the biodiversity emergency.
The theory was that it could offset a substantial fraction of human carbon emissions. However, the researchers found it had “barely any measurable effect”.
Professor Caroline Lehmann, of the Royal Botanic Garden Edinburgh, who worked on the new report, said the focus needed to shift from the notion of land ownership to that of land stewardship, as that would bring more voices to how landscapes and their ecosystems are shaped.
“Planting trees will not fix climate change, just as simply fencing off land or excluding people from land will not create resilient ecosystems,” she said. “Certainly not against the backdrop of the degradation we have created over the last centuries.
“The focus on storing anthropogenic emissions in ecosystems, which has influenced national and international land policies globally, as I would suggest, distracted from the need for a rapid and just energy transition,” she said.
Lead author Csaba Tölgyesi, of Hungary’s University of Szeged, said: “A few years ago, tree-planting received global popularity but it turns out that it can have serious adverse effects, necessitating a more inclusive approach, considering all possible natural ecosystem types.”
She said more realistic modelling had been used in the new study than had been used previously to look at the issue. This led not to a slight adjustment but to a “massive” difference from previous carbon capture potentials.
“We found that, in most climate scenarios, ecosystem restoration has barely any measurable effect on atmospheric carbon concentrations,” said Tölgyesi.
“In the greenest of all, only 17% of human emissions can be recaptured by 2100, while in the business-as- usual scenario, it is less than 4%.”
The researchers conclude that there is an “urgent” need for a change of direction in polices to transition to a low-carbon economy.
Dr Lehmann added: “It’s essential we recognise the complexities and look to the already excellent scientific understanding we have about climate change and biodiversity to build resilience through context-specific land management.
“Food production needs to prioritise soil health. In Scotland, with our extensive intensive agriculture and forestry, we need to think about practices that enable holistic land management.
“Regenerative agriculture might be a trendy term, but the mindset associated with it is one of approaching land holistically to promote soil health and reduce reliance on inputs such as fertilisers and pesticides while balancing productivity.”
Land has to be looked at holistically, according to Dr Lehmann.
“Climate change and the biodiversity crisis are not separate issues just as the diverse threats posed to ecosystems, such as land fragmentation, pesticides, and exploitation, do not act in isolation,” she said.
“We need to proactively manage land for outcomes that balance biodiversity, ecosystem services and future resilience. This requires both good science, to form the evidence for policy and management, and also robust equitable governance and buy-in from our wider society to enable it.”
Humans also need to recognise that nature, its ecosystems and biodiversity, is essential for human life.
“Supporting understanding of and access to nature and its role in our everyday lives is something that can benefit us all individually and collectively,” said Dr Lehmann.
