Silvana Di Sabatino is a Professor in Atmospheric Physics at the University of Bologna, Italy, where she coordinates the atmospheric physics group that works on matters relating to meteorology, dealing with extreme weather events and climate adaptation. Professor Di Sabatino was the coordinator of the Horizon 2020-funded OPERANDUM project which set out to provide science-based evidence for the usability of nature-based solutions ranging from local to landscape scales.
Can you tell us about your work on nature-based solutions in climate adaptation, including with the OPERANDUM project?
When talking about climate hazards, we need to differentiate their topology, to understand if it is river flooding that is associated with extreme rain and flash floods, or coastal flooding associated with coastal erosion and sea storms. To address these, we of course need climate mitigation to reduce emissions, but we also need climate adaptation, particularly nature-based solutions.
This doesn’t mean we shouldn’t have typical engineering approaches in place, but these should be integrated with nature-based solutions. Each country and region in Europe should be including measures that evaluate the possible benefits of nature-based solutions.
From many years working on this topic, we can see that policies have not been so strong. There are limitations to nature-based solutions, as they can be difficult to maintain and their effectiveness can vary. This can limit their uptake, particularly on private land, which has been a barrier to scaling these approaches to the landscape level here in Italy. The uptake and scaling of these measures cannot be entirely imposed by policy and legislation, there also needs to be a concerted effort to engage with communities and demonstrate their cost-effectiveness.
Why are nature-based solutions a particularly interesting area of research for climate adaptation?
Silvana Di Sabatino: Nature-based solutions can be cost-effective, for example planting trees is less expensive than building a bridge or using trees with deep roots to make embankments more robust in place of using concrete gravel. These approaches do need continuous monitoring and care, which needs to be considered in their costs.
These solutions have been proven to be effective for specific problems, but they require working on the local level to factor in the economic and community context. A plus of nature-based solutions is that there is often more than one solution, with smart, combined approaches that can enhance the benefits.
For example, in coastal areas here in Italy, we are experiencing coastal erosion, often in areas under heavy pressure from development. When addressing this coastal erosion, there are several nature-based solutions options. In the OPERANDUM project, we had a dune restoration prototype in the northern part of the Emilia-Romagna region where we rebuilt the dunes with natural components and revegetation. However, this action alone was not sufficient, we also needed to address the ocean component, which involved having more Posidonia oceanica [a Mediterranean species of seagrass] that acts as a buffer layer. This means that we then have the dune and seagrass restoration actions working together in a smart way to address coastal erosion now and in the future.
These kinds of approaches require local knowledge and engaging with a wide range of stakeholders, be those landowners and farmers, or those working in the tourism industry, to ensure that they are properly designed to the local context. This means we also need to educate the next generation of engineers to be able to deploy nature-based solutions.
What are the potential benefits and limitations of nature-based solutions for climate adaptation?
Silvana Di Sabatino: There is an array of benefits of nature-based solutions but there are also limitations, and we need to be honest about these to avoid any greenwashing of the science. There is value in using hybrid nature-based solutions and traditional approaches, which can be a way of educating people about nature-based solutions to encourage their adoption.
In Europe, there are of course meteorological and hydrological differences between countries, but there are also cultural differences in respect to business and nature that may constrain nature-based solutions, which means uptake will be happening at different speeds. So again, we need to be honest about these considerations when designing policies, to avoid fostering negative viewpoints on nature-based solutions.
Another aspect of nature-based solutions is that climate change is having widespread impacts on human health. These include impacts on our physical health, for example increased cardiovascular stress in response to severe heat, and also on our mental and neurological health arising from extreme weather events, like stress from loss and damage to properties. Nature-based solutions can be very beneficial for addressing these impacts as well, through access to nature and green spaces improving mental and physical health and wellbeing.
As a physicist, I am sceptical when a solution is sold as a perfect one, even for nature-based solutions, as simplistic approaches cannot capture the complexity of our societies. Nature-based solutions can be the correct option, if the problem is properly defined and considered with thorough analysis, correct modelling and a methodology that provides proof that the approach is suitable for the context and will be effective.