The research, put together by hundreds of scientists from around the globe led by the Crowther Lab, shows that diverse, restored forests have huge carbon capture potential even when only looking at areas with less human activity.
The world’s forests are in a poor state, with ongoing deforestation decimating their ability to capture carbon dioxide, the main cause of global warming.
“Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land
use and climate have considerably reduced the scale of this system,” according to the study.
Ending deforestation must be a top priority to restore global biodiversity, according to Lidong Mo, one of the study’s lead authors.
“Most of the world’s forests are highly degraded. In fact, many people have never been in one of the few old-growth forests that remain on Earth,” he said.
However, some restoration efforts are hampered by previously forested land being taken up with agriculture or urbanisation, which can create a conflict of interest over land use.
To avoid this, the study focused on areas with little human activity, using ground-sourced and satellite approaches to evaluate carbon capture potential outside of agricultural and urban land.
It found that approximately 61% of this forest carbon capture potential can be achieved by protecting existing forests and allowing them to regrow to maturity. The remaining 39% can be achieved by reconnecting fragmented landscapes through community-led restoration and management.
The need to restore forests was highlighted earlier this month when EU legislators agreed an historic law to reverse nature loss and meet an international goal of restoring 30% of land and seas by 2030.
In forests, for instance, EU countries will be required to roll out measures that enhance biodiversity and increase positive trends, including for bird populations and the quantity of deadwood.
With the nature restoration law agreed, the EU will go to the COP28 international climate conference with “an important building block for mitigating the climate crisis and adapting to climate change,” said Jutta Paulus, a German green lawmaker who was the chief Parliament negotiator on the law.
The EU’s biodiversity strategy also includes plans to plant three billion trees in Europe by 2030 to mitigate climate change, store carbon, and help adapt to global warming.
Communities at the centre of forest restoration
But the researchers emphasise that communities must be at the heart of restoration efforts and involve local communities and Indigenous Peoples.
“Only when healthy biodiversity is the preferred choice for local communities will we get long-term carbon capture as a bi-product,” said Thomas Crowther, senior author of the paper and professor at ETH Zurich.
Restoration should also fit the natural environment, which includes only planting trees in areas where they would naturally grow rather than in other ecosystems, such as peatlands.
“Global restoration is not only about trees,” said Constantin Zohner, a senior researcher at ETH Zurich. “We have to protect natural biodiversity in all ecosystems, including grasslands, peatlands, and wetlands that are equally essential for life on Earth”.
Crowther also insisted that carbon capture by forests cannot be used as a replacement for reducing fossil fuel emissions, which are already causing droughts, fires and other erratic weather that damages forests.
“Restoration is not about mass tree plantations to offset carbon emissions. Restoration means directing the flow of wealth towards millions of local communities, Indigenous populations, and farmers that promote biodiversity across the globe,” said Crowther.
“My biggest fear is that corporations misuse this information as an excuse to avoid cutting fossil fuel emissions. The more we emit, the more we threaten nature and people,” he added.