As we look towards a net-zero future, land sinks are a potential pathway to achieve our goal. This is where nature-based solutions come into the picture. Research led by The Nature Conservancy and 15 other institutions highlighted that nature-based solutions could reduce emissions up to 37% by 2030 to keep the global temperature under two degree Celsius.
Nature-based solutions can be an effective tool against this war against climate change. Natural ecosystems like mangroves, wetlands, grasslands and forests are among the few solutions that can act as natural sinks for carbon dioxide in the atmosphere. Besides keeping the carbon dioxide level in check, a report by the OECD highlighted that these solutions can have significant economic and social benefits, such as help in job creation.
A similar argument was also placed forward by The Nature Conservancy. According to their estimate in the Northeast of the United States, coastal wetlands helped prevent a direct loss of over USD 600 million during Hurricane Sandy. Based on the published case studies, nature-based solutions seem like a win-win situation for all as they provide a home to biodiversity and save us from climate change.
Let us understand the process in more granularity — nature-based solutions absorb CO2 from the atmosphere and store it in the woods and roots of the plants. This daily miracle of plants was believed to be one of the solutions to saving the planet. According to the Land Use, Land Use Change and Forestry report by IPCC, land, plants and soil can hold about 2,500 gigatonnes of carbon. However, we must take cognisance that this system has a finite capacity to take in carbon.
These factors have resulted in proliferating a number of efforts to scale nature-based solutions globally to mitigate climate change. However, a fundamental misunderstanding about nature-based solutions can lead to devastating consequences. Does it sound like a paradox? How can our favourite trees be the culprit?
The answer lies in the complexity of nature-based solutions. While these solutions are highly context-specific, we must avoid planting trees where they do not belong. Every ecosystem is unique on its own. If we consider a wetland or grassland, each ecosystem supports a different form of vegetation, making it unique. An ecosystem is one of the complex systems globally; despite scientists trying for years, we hardly understand anything about them.
Thus, a simple notion of introducing a ‘fast-growing species to capture more carbon’ can lead to consequences as severe as the collapse of the ecosystem. Let us not forget what happened during REDD+. Acres of a healthy lush forest was cut only to plant non-native, fast-growing species, which ultimately led to the collapse of the entire ecosystem. Under the umbrella of REDD+, emphasis was placed on the number of planted trees rather than the health of the ecosystem.
In most cases, fast-growing non-native species such as eucalyptus, pine and others were planted, which did more bad than good to the forest ecosystem. It is a fundamental rule in ecology that a diverse system is much more resilient than a monoculture plantation.
While we ardently believe the fact that natural systems are an essential tool for building climate resilience, we must also consider that no natural system can ever absorb the quantity of carbon dioxide released by fossil fuels. Rather than being lulled into this false notion, we need to discontinue the case of business as usual.
As we drive towards a zero-carbon future, nature-based solutions are only one kind of tool in our toolbelt. Other strategies of decarbonisation must accompany it. These arguments might impel you to think that are we pushing against the fact that nature-based solutions are not effective. Emphatically not, being an ecologist, nothing will give joy to my heart than a greener world. We are just against the notion of thinking of nature-based solutions as an effective tool for climate change mitigation, because their benefits are not limited to carbon sequestration; the natural system is home to millions of species. In addition to this, they provide food, medicine, water and several indirect benefits to humankind.
Nature-based solutions are propitious. They need to be scaled and promoted — not because they are a silver bullet, but because they are one of the pathways to paint a more promising present and resilient future.