New Delhi: A new study shows that natural forest recovery could capture approximately 226 gigatonnes of carbon, but only if we also reduce greenhouse gas emissions. The study highlights the importance of forest conservation, restoration, and sustainable management in moving towards international climate and biodiversity targets. The researchers stress that this potential can be achieved by incentivizing community-driven efforts to promote biodiversity.
The forest carbon potential has been a highly controversial topic. Four years ago, a study published in the journal Science found that the restoration of forests could capture over 200 gigatonnes (Gt) of carbon, drawing down approximately 30 per cent of excess anthropogenic carbon.
While this study elevated a discussion about the role of Nature in fighting climate change, it also raised concerns about the adverse environmental impacts of mass tree plantations, carbon offsetting schemes, and greenwashing. While some scientific studies have supported the scale of this finding, others argued that this forest carbon estimate could be up to 4 or 5 times too high.
To address this controversial topic, researchers led by the Crowther Lab at ETH Zurich joined forces to build an integrated assessment using a comprehensive range of approaches, including vast ground-sourced data and satellite datasets.
Forest carbon capture
Due to ongoing deforestation, the total carbon stored in forests is ~328 Gt below its natural state. Of course, much of this land is used for extensive human development, including urban and agricultural land. However, outside those areas, researchers found that forests could capture approximately 226 Gt in regions with a low human footprint if they were allowed to recover. Approximately 61 per cent of this potential can be achieved by protecting existing forests so that they can recover to maturity. The remaining 39 per cent can be achieved by reconnecting fragmented forest landscapes through sustainable ecosystem management and restoration.
“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,” says Lidong Mo, a lead author of the study published in the journal Nature. “To restore global biodiversity, ending deforestation must be a top priority.”
The dataset revealed that biodiversity accounts for approximately half of the global forest productivity. As such, the researchers highlighted that restoration efforts should include a natural diversity of species to achieve the full carbon potential. In addition, sustainable agricultural, forestry, and restoration practices that promote biodiversity have the greatest potential for carbon capture.
A fundamentally social endeavour
The authors stress that responsible restoration is a fundamentally social endeavour. It includes countless actions such as conservation, natural regeneration, rewilding, silviculture, agroforestry, and all other community-driven efforts to promote biodiversity. It requires equitable development driven by policies that prioritize the rights of local communities and Indigenous people.
“We need to redefine what restoration means to many people,” says senior author Thomas Crowther, a professor at ETH Zurich. “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. We get long-term carbon capture as a byproduct when healthy biodiversity is the preferred choice for local communities.”
The researchers conclude that ecologically responsible forest restoration does not include the conversion of other ecosystems that would not naturally contain forests.
“Global restoration is not only about trees,” says 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.”
Study warns emissions to continue
This study highlights the importance of natural, diverse forests in contributing 30 per cent of carbon drawdown potential. However, forests cannot be a substitute for cutting fossil fuel emissions. The study warns that if emissions continue to rise, ongoing droughts, fires, and warming will threaten forests and limit their ability to absorb carbon.
“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. There can be no choice between reducing emissions and protecting Nature because we urgently need both. We need Nature for climate and climate action for Nature!” says Crowther.
