What is meant by the so-called nature-based solutions (NBS)?
Two definitions have been created in order to describe this issue:
The first of them has been formulated by the International Union for Conservation of Nature (IUCN), according to which they are: “activities aimed at the protection, sustainable management and restoration of natural or modified ecosystems, in order to effectively adapt the space concerned and at the same time deal with social challenges, ensuring people’s well-being and benefits for biodiversity ”
The second one has been defined by the European Commission, therein solutions based on nature are defined as: “solutions inspired and supported by nature, designed in order to meet social challenges – they are cost-effective and provide environmental, social and economic benefits and help build resilience”
NBS solutions are used on various scales: from the macro-scale (an example may be the planting of mangroves protecting the coast against the effects of storms or hurricanes in the Dominican Republic), they can also be used on a micro-scale (as an element of urban adaptation / mitigation of the effects of climate change in urban spaces, such as the construction of rain gardens in Gdańsk).
In adapting urban spaces to climate change (or mitigating the effects of climate change), tools are used that help fight frost / heatwaves, counteract local flooding, floods or the effects of rising sea and ocean levels, and increase biodiversity in cities, which allows building stable ecosystems.
It should be remembered that compared to the so-called gray infrastructure, NBS solutions are multi-faceted, one could say multi-functional tools. The previously mentioned “rain garden”, apart from rainwater retention, will also play other roles:
It is also vital to integrate the tools constituting the green infrastructure with the tools belonging to the group of gray infrastructure. Using the example of a “rain garden” again – its efficiency can be multiplied by installing drains, and thus the possibility of transferring excess water to retention reservoirs located e.g., underground.
NBS solutions can also be divided according to the spatial criterion or according to the relation tool vs. building. Thus, we have solutions: integrated with the building, between buildings, next to the building, at a distance from the building.
Another type of division of tools can be according to the spatial aspect. Some tools are used as linear solutions, some as surface solutions, and others as point solutions.
Introducing NBS solutions in cities is also aimed at participating in other processes of urban change. They are often applied in processes related to the revitalization or modernization of degraded urban spaces (post-industrial, post-port, post-military, post-communication areas), courtyards located in the downtown tissue, or in modernist housing estates. For the implementation of NBS tools, we also use gaps or scraps of space (small undeveloped plots, areas under bridges, etc.)
In cities, we have spaces with different ownership status – state-owned or city-owned plots, but also many private spaces, as well as with unregulated ownership status. Therefore, NBS solutions can be implemented top-down or bottom-up by diverse groups of stakeholders. At the same time, the activities of local communities may affect the implementation of NBS solutions by top-down organizations.
The type and final shape of individual NBS solutions located in urban spaces will therefore depend on whether they are bottom-up or top-down activities, whether these solutions are applied in previously developed spaces or in order to transform the existing city tissue. The way of managing these tools, financing their construction, functioning or maintenance also requires an answer. When we implement solutions in the existing city tissue, the economic status of their inhabitants is important as well as special attention to ensuring that the implementation of NBS does not trigger the processes related to gentrification.
The implementation of NBS solutions in city spaces as a component of their adaptation to climate change or mitigating the effects of climate change is burdened with many barriers. Examples of them are listed in the table:
Examples of barriers preventing the implementation of NBS solutions in cities.