Mapping the effectiveness of nature‐based solutions for climate change adaptation

The paper is the first global systematic review of the effectiveness of nature-based solutions and provides evidence that nature-based solutions play a key role in addressing the impacts of climate change, but also highlights potential trade-offs to be avoided and evidence gaps where further study is needed.

The review investigates nearly 400 scientific studies including both real-world cases, and modelled scenarios. Of the real-world cases, most nature-based interventions (59%) were found to reduce climate impacts such as flooding, soil erosion and loss of food production, although in 12% of interventions some negative climate impacts were exacerbated.

Social, environmental, and greenhouse gas reduction benefits were also reported from nature-based solutions, supporting the proposition that they have an important role to play in global efforts to mitigate climate change and biodiversity loss, while also achieving other sustainable development goals. Although comparative studies were rare, where data were available nature-based solutions were found to be as or more effective than alternative approaches.

While the study highlights many successful nature-based solutions, there are still considerable research gaps. In particular, the evidence base is biased toward the Global North, despite communities in the Global South being generally more vulnerable to the impacts of climate change and having the highest direct dependency on natural resources. There is also a great need for assessments of cost-effectiveness of nature-based solutions compared to alternative interventions, and integrated assessments looking at multiple different types of outcome (climate change adaptation and mitigation, social and ecological outcomes) simultaneously from the same nature-based solution, aiding identification of synergies and trade-offs.