John Carstensen discusses the role of nature-based solutions in tackling climate change
Climate change is continuing at worrying pace despite our – in fairness, modest – efforts to decarbonise our economies and prepare for the impact on our lives and economy. It is increasingly clear that we are not going to be able to stay within the 2°C global temperature increase limit set out by international climate change agreements.
Fatih Birol, head of the International Energy Agency, has made it clear that if the world is to meet its 2050 net-zero carbon goal, we must take action on decarbonisation this year as part of the COVID-19 recovery response. The UK’s Climate Change Commission has just released its progress report on the UK’s efforts – and the headline is that we’re off-track in most areas and sectors.
We need to embrace all possible approaches to decarbonisation and adapting for the future. There must be fundamental changes to our industry, transport, farming and housing energy infrastructure. Much of what we need to do, such as renewable energy and electrification, is well-established, but we need to become better at implementing nature-based solutions if we are to achieve the scale and speed needed to respond to climate change.
Scale of investment
In September last year, the Global Commission on Adaptation published a report estimating that US$1.8trn
was needed by 2030 to meet global adaptation needs.
This can’t all come from the public sector and development agencies; agencies and governments will have to use their resources to leverage private sector finance.
From a global perspective, a US$1.8trn investment concentrated in five categories – weather warning systems, infrastructure, dry-land farming, mangrove protection and water management – would yield US$7.1trn in benefits, nearly four times the investment. Yet the private sector is only going to invest if there’s a discernible return on their particular investment, and if that return comes with a minimal or manageable risk. We need to work out incentives that will help to transfer risk and economic benefits.
During the past few decades, more and more services that are dependent on environmental resources have started exploring ecosystems services, where nature solutions are applied. There are interesting examples of how valuing ecosystems services can help pay for protective interventions, and the UK water sector is exploring such options in many places to help maintain a clean water resource at a reasonable expense, as well as serving ambitious aims for both climate change and biodiversity.
Many of our water utilities have embraced a nature-based approach that has moved away from simply focusing on treating a water resource, and towards managing the entire ecosystem. Yorkshire Water, for example, has adopted a comprehensive analytical approach to understanding all its challenges, including weather extremes, rising sea levels and dry summers. Its approach aims to understand its customer base and their economic challenges, taking a local community focus. This has led to development of catchment strategies, but also nature-based solutions in the catchment area to slow the flow of the water. These solutions include the restoration of 43 hectares of blanket bog and the planting of up to 200,000 trees. Scottish Water and many other water utilities companies are making similar changes – partly because it is effective and economically sound to do so, but also because the companies themselves will benefit from the investment.
Circles of benefit
Unfortunately, the areas where investments are needed are often not directly connected to the people who will benefit. Connecting the circles of economic benefit will require innovation.
An interesting example is how those in charge of the New York City water supply have made a voluntary arrangement with local farmers in the Catskills, in which the farmers are paid for taking measures that reduce the amount of pesticide and nutrient run-off from farms. This in turn cuts the cost of treating the drinking water for the utility companies, and has avoided the need for regulation and expensive control regimes.
Insurance schemes are being explored with some degree of success, but they will only be part of the solution if climate impacts such as storms and floods are not recurring too frequently. Insurance is already a challenge for small businesses in areas that are repeatedly hit by flooding. Strong adaptation measures can allow insurance schemes to help spread the risk of extreme weather events – and nature-based solutions are integral to their success.
Nature-based solutions must also be rolled out in developing countries, where many nature-based benefits are found on a large scale. They can also be used effectively to address climate change issues, both in reducing GHG emissions and in helping communities adapt to the impacts of climate change and become more resilient.
The potential to achieve significant reductions in GHG has been highlighted in recent papers, such as ‘National mitigation potential from natural climate solutions in the tropics’ (Griscom et al., January 2020) and ‘Natural climate solutions’ (Griscom et al., October 2017). The former includes an overview of 12 pathways to reduced emissions through the protection, management or restoration of natural resources in tropical countries.
It is especially important to notice the volume of mitigation potential, not just from the individual areas of intervention, but also from the cumulative effect if all the measures are undertaken. These measures will not only have a climate impact, but also help protect biodiversity.
Intact mangrove forests and sea grass will slow wind and water flow to reduce the impact of storms and coastal floods, and they will also be a welcoming host to many species, thereby supporting fishing and agriculture.
There is a need to undertake the same type of research for nature-based approaches when adapting to climate change impacts. There are good indications that both drought conditions and floods can be better managed by, for example, rewilding rivers, introducing beavers and slowing the flow of flood water. And there are many other types of nature-based solutions, both in developed countries such as the UK and in developing countries; we need to embrace them all in order to reduce our greenhouse gas emissions and make the inevitable adaptations we will need because of climate change.
The applications stretch from climate smart agricultural practices and the preservation of wetlands and peatlands,
to the greening of cities using parks, green spaces and green buildings, which will help counter the effect of extreme heat.
Nature-based solutions will serve multiple purposes and reconnect us with the natural world.
John Carstensen is climate resilience lead at Mott MacDonald