Nature-based climate solutions (NbCS) are currently ‘falling short’, and need to be restructured in order to work more effectively, a new study led by researchers from the University of Utah, University of California Santa Barbara, and other institutions has found.
The study, which was published in the journal Nature, and was funded by the National Science Foundation, analysed a number of strategies for improving NbCS, particularly focusing on forests’ role in carbon storage.
Climate change mitigation
“Forests have potential as nature-based climate solutions, aligned with broader sustainability benefits,” commented co-author Anna Trugman, an associate professor in UCSB’s Department of Geography. “Unfortunately, a broad body of literature has revealed widespread problems in forest NbCS projects and protocols that undermine the climate mitigation of forest carbon credits and hamper efforts to reach global net zero.”
Both Trugman and her fellow authors agree that improving NbCS will require better science and policy efforts going forward.
While forests absorb a significant portion of carbon dioxide emitted by human activities, deforestation in turn releases large amounts of carbon – contributing nearly 1.9 gigatonnes of carbon emissions annually, comparable to the yearly emissions of large countries. Therefore, preventing forest loss needs to be a key focus of future climate efforts.
“Nature-based climate solutions are human actions that leverage natural processes to either take carbon out of the atmosphere or stop the emissions of carbon to the atmosphere,” said lead author William Anderegg, a professor of biology at the University of Utah. “Those are the two main broad categories. There’s the avoided emissions, and that’s activities like stopping deforestation. Then there’s the greenhouse gas-removal pathways. That’s things like reforestation where you plant trees, and as those trees grow, they suck up CO2 out of the atmosphere.”
Main challenges
The research points to four main challenges that limit the effectiveness of nature-based climate projects. Firstly, feedback effects, such as changes in the land’s reflectivity or albedo can offset carbon storage benefits. Secondly, NbCS need to produce additional climate benefits that would not have otherwise occurred without the project being in place.
Thirdly, ‘leakage’ can take place when protecting one area leads to increased emissions or land use changes elsewhere, negating climate benefits. Finally, the durability of carbon storage is critical, with carbon stored in trees and soils needing to remain locked away for decades or centuries.
“You have to know how big the risks are, and you have to account for those risks in the policies and programs,” Anderegg added. “Otherwise, you’re going to lose a lot of that carbon storage as climate change accelerates the risks.”
The study recommends reforms to improve NbCS by incorporating these factors into policies and funding mechanisms. Read more here.
