In the 21st Century, society is faced with various climatic and non-climatic challenges that can lead to abrupt, and in some cases, irreversible environmental change that adversely impacts human development. For instance, climate change is increasing the frequency, intensity, and magnitude of disasters, leading to a higher number of fatalities and injuries as well as increased property and economic losses, while rapid population growth and urbanisation are resulting in ecosystem degradation from excessive water withdrawal, eutrophication, and pollution.
Rather than relying on conventional engineering solutions to address these challenges, there is growing recognition of the need to work with ecosystems to ensure liveability in cities, help communities cope with and recover from disasters, and adapt to and mitigate climate change, all the while protecting natural ecosystems and biodiversity.
Nature-based solutions (NBS) are inspired and supported by nature and use, or mimic natural processes and can be applied strategically and equitably to help societies address a variety of climatic and non-climatic challenges. At the same time, NBS can bring about multiple economic, environmental, and social benefits, such as reduced infrastructure costs, job creation and green growth, and health and recreational opportunities. NBS come in all shapes and sizes, two examples of which follow:
In the context of climate change mitigation, NBS is referred to as ecosystem-based mitigation (EbM), which encompasses a diverse set of mitigation approaches, including the sustainable management of forests, use of native assemblages of forest species in reforestation activities, conservation and restoration of peatlands and wetlands, protection of the ocean sink, improved grassland management, and environmentally sound agricultural practices. In addition to mitigating greenhouse gas emissions, EbM provides a range of co-benefits, including less biodiversity loss because of slower climate change.
Sky Ocean Rescue, WWF, and Swansea University have launched the largest seagrass restoration project ever in the UK. The project involves planting seagrass seeds over two hectares in Dale Bay, Pembrokeshire. Seagrass captures carbon from the atmosphere up to 35 times faster than tropical rainforests. The freshly planted seagrass is expected to trap up to half a ton of carbon dioxide per hectare each year once fully established by ‘sponging’ carbon dioxide from the atmosphere. In addition to trapping carbon dioxide, the seagrass will act as a nursery for various marine life, including endangered seahorses and sea snails. In total, by restoring two hectares, the seagrass will support around 160,000 fish and 200 million invertebrates.
In the urban context, NBS can be applied as green infrastructure (GI), a strategically planned network of natural and semi-natural areas designed and managed to deliver a wide range of environmental, economic, and social benefits. GI varies in scale and scope, including buildings, public spaces, water bodies and drainage systems, and green corridors. GI provides three main opportunities: first, GI supports economic development in urban areas, second, urban planning that incorporates GI has a positive environmental impact, and third, GI contributes to the social dimension of urbanisation, such as increasing people’s happiness and general health.
Recognising the value of nature in reducing the urban heat island effect and creating liveable, green, and sustainable places, the Government of Western Australia has released the Waterwise Perth Action Plan, which sets out the direction for transitioning Perth to a leading Waterwise city by 2030. The Waterwise Perth Action Plan calls for an increase in green space in urban environments through various initiatives, including the Waterwise Greening Scheme. This is a scheme where Waterwise Councils can receive up to $10,000 in funding to support a variety of Waterwise greening initiatives, including green street programs and demonstration Waterwise gardens, for example, reclaimed public open space gardens, all of which provide multiple co-benefits including improving water quality, improving community health and well-being, increasing biodiversity, and cooling local communities.
NBS come in a variety of shapes and sizes and can be applied across marine and terrestrial environments to solve a variety of societal challenges, including mitigating climate change and enhancing the liveability of cities, examples of which include the restoration of seagrass to mitigate emissions while providing a nursery for marine life and the use of green spaces in cities to reduce the urban heat island effect while providing multiple environmental and social co-benefits.
Author, Robert C. Brears is an international sectoral expert on water for the UN’s Green Climate Fund, Editor-in-Chief of the Palgrave Encyclopedia of Urban and Regional Futures (Springer Nature), author of 10 books, including Nature-based Solutions to 21st Century Challenges (Routledge), and the founder of Our Future Water