Driving change
Our ecological enhancement of the Lower Lam Tsuen River in Hong Kong has seen concrete channels replaced with natural riverbeds.
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Deploying natural solutions to society’s big challenges could deliver multiple benefits, say Lucy Morton and Marieke Nieuwaal.
Net zero, climate resilience, environmental degradation, flooding, food security. They’re some of the big issues facing us. Solving them is complex. Nature is part of the solution in most cases.
And, because nature-based solutions tend to generate more benefits than just those that were originally intended (so called co-benefits), considering how and where we can use them from the outset of a project, as part of an integrated approach, is how we can maximise every positive outcome – for society and for nature.
Nature-based solutions can be less costly to deliver than conventional infrastructure and can require less maintenance. Where there is an additional maintenance cost, the wider benefits can be monetised to offset this. Assigning values to some of the co-benefits, including carbon sequestration and improving water quality without costly treatment, enables decision makers to quantify the trade-offs from competing changes to land, better identity solutions that will enhance both human development and conservation, and to deliver a robust business case.
Life-support systems
Nature is our life-support system. Our forests, rivers, land, minerals and oceans provide valuable flows of goods and services that are important for maintaining good water quality, supporting biodiversity and livelihoods, maintaining soil fertility and providing food, and for reducing air pollution and enabling us to adapt to climate change.
Nature-based solutions protect, restore and enhance these vital ecosystems, as well as help to address societal challenges and deliver multiple additional benefits for people and nature.
Restoring bends in rivers, installing leaky dams, changing the way land is managed to enable soil to absorb more water, maintaining flood plains and creating saltmarshes on the coast will help to naturally manage floods. Mangrove planting can reduce the impacts of storm surges on sea defences and reduce build costs and maintenance in tropical and sub-tropical coastal areas. All of these measures are natural solutions to safeguard people and communities, and they also help to improve habitats and biodiversity.
If done the right way and in the right place, planting native trees and other vegetation is a cost-effective way of removing carbon from the atmosphere, and of securing biodiversity benefits. Trees can also purify our air and provide shading and cooling, making our towns and cities better places to live, work and play, and reducing respiratory ill health. Green corridors can offer safe routes for active travel. Trees also raise nearby property values. One US study found that every US$1 spent on tree planting could save US$7 of expenditure in other areas.
Driving change
Commitments to net-zero emissions are making nature-based solutions increasingly attractive to public authorities because they have the potential to tackle both climate mitigation and adaptation challenges at relatively low-cost. However, we are also experiencing a biodiversity crisis. Nature-based solutions address both issues at the same time.
Improving a site’s biodiversity is known as biodiversity net-gain. It goes beyond doing no harm to nature and is another driver of change. Development projects funded by international financial institutions have had to demonstrate biodiversity net-gain for the most sensitive habitats for almost a decade and this is what the International Union for Conservation of Nature (IUCN) global standard for nature-based solutions requires. The UK government is now planning to introduce mandatory biodiversity net-gain in England. It will require most developments to demonstrate a percentage increase in biodiversity.
Nature-based solutions can also help achieve the UN Sustainable Development Goals, including helping to build sustainable cities and communities and improving life on land and below water.
Some projects already incorporate nature-based solutions. Some clients demand them.
Our work on the Leeds flood alleviation scheme in the UK includes implementing natural flood management measures across the River Aire catchment area to reduce flood risk in the city and deliver wider benefits, such as carbon sequestration, biodiversity improvements and societal gains. Our ecological enhancement of the Lower Lam Tsuen River in Hong Kong has seen concrete channels replaced with natural riverbeds, delivering aquatic micro-habitats including pools and riffles, vegetation and resting ground for birds, while still providing the water resources and hydrological management the region needs – including drinking water for the people of Hong Kong.
But we can do more if nature-based solutions were considered at the start of all our projects, so we work with nature and adopt systems thinking to amplify the many potential benefits – whether that is reducing carbon, improving asset resilience and performance, involving communities or promoting biodiversity, for example.
To meet project needs and maximise the benefits for people and nature, design and delivery teams must listen to and work with various stakeholders to understand, adapt and change projects so they work with the human and natural ecosystems in which they are sited.
Monetising the co-benefits will help to drive change and secure funding. Carbon credits, biodiversity net-gain and natural capital accounting all place a value on nature and the flows of services it supplies so they can be more readily factored into a project business case. Engaging stakeholders and identifying the multiple benefits at the outset is an opportunity to enlarge the potential sources of financing, including mobilising private finance.
We use geographical information systems (GIS) to map and assess a physical location for its economic activities and environmental context and character, and tools – such as Stanford University’s InVEST model and the UK government’s ENCA (Enabling a Natural Capital Approach) guidance and Biodiversity Metric – to assign values to different things, such as carbon sequestration, habitat quality and recreation.
A systems-based approach considers the interconnections and where nature can play a part to deliver the best engineering, environmental, economic and social outcomes. Nature-based solutions can complement or substitute for some or all of the functionality of what might have traditionally been built. The difference is that it uses nature in ways that can achieve so much more that the original purpose.
