Nature-based solutions: accelerating the transition with quantifiable impact
Nature-based solutions (NbS) protect or restore natural habitats and even create new ones in places they did not exist previously. Examples include creating green roofs or urban parks, and depaving to create new natural spaces. They improve and contribute to biodiversity, build resilience to heat and flooding, and create myriad additional environmental, social and economic benefits. Mapping NbS and modelling the ecosystem services provided by them, the EU-funded REGREEN project advanced the understanding of what NbS work best for which challenges and where. Its tools and reports, openly available on the project website, will accelerate the transition towards equitable, green and healthy cities.
Mapping and modelling ecosystem services
REGREEN mapped the extent of nature in several European and Chinese cities and created detailed, quantitative scenarios for how it could change. “Through ecosystem services models, REGREEN looked at, for example, what impact increasing tree cover would have on air quality and mortality, or what impact planting trees along streams would have on water quality,” explains Marianne Zandersen of Aarhus University, project coordinator. Well-being and benefits were both quantified and qualified by integrating health economics with citizens’ perceptions and preferences. These were incorporated into a total economic value of NbS. “NbS are often undervalued in decision making because assessments lack the full range of social, environmental and health benefits of NbS. However, value should be recognised as more than an economic metric,” adds Zandersen.
Urban living labs: teaming up with local authorities in European cities
REGREEN worked with two municipalities in Denmark and Croatia, and a regional agency in Paris. The three cities differ widely in scale and complexity but share the same types of challenges and potential. Participation in REGREEN served as a catalyst for strategic shifts in planning, capacity building and stakeholder outreach. It also secured the mandate for further exploration and implementation of NbS in all three cities. Of particular note, regional policy makers in Paris used a tool and report by REGREEN on renaturing cities to create a new agency with a multi-million-euro budget. It will finance depaving and renaturation projects and provide technical support to municipalities in the region. The report, available in four languages, will help European cities stop the decline in urban green space and increase it in alignment with the European Nature Restoration Law.
Raising awareness among stakeholders of all ages
REGREEN has something for everyone who wants to take action or learn more about Nbs. Its ‘Nature Solutions Platform’ and Greenopolis learning platform target adult stakeholders, teachers and children respectively. Interactive 5x8 m2 walkable floor maps that reproduce aerial photos of municipalities inspired unique reflections and innovation to solve challenges in urban areas. REGREEN also published 29 public deliverables and 34 open-access peer-reviewed articles by project end, with 29 more submitted or in preparation. It produced the REGREEN NbS handbook for ecosystem restoration and urban resilience, policy briefs and a podcast series as well. REGREEN has holistically integrated ecosystem services modelling and mapping, quantitative benefits’ assessments, urban planning, education and business, taking into account the shared benefits of NbS. “The brilliant thing about NbS is that they are multi-functional – one type can help reduce several challenges at a time, making them cost-effective compared to engineered solutions. It’s time to start scaling them up,” concludes Zandersen.
Keywords
REGREEN, NbS, urban, nature-based solutions, ecosystem services, modelling, municipalities, policy, biodiversity, urban planning
