In the face of the impending climate crisis, now more than ever it is critical that we develop and implement solutions to adapt to a changing world. Nature-based solutions (NBS) may hold the key to sustainable development to protect communities and ecosystems across the globe. NBS is defined by the International Union for the Conservation of Nature and Natural Resources (IUCN) as “actions to protect, sustainably manage and restore natural or modified ecosystems which address societal challenges effectively and adaptively, while simultaneously providing human well-being and biodiversity benefits.” NBS comes in many forms depending on region and issues being addressed. Its versatility as well as its ability to provide numerous unintended benefits make it a solution of growing interest.
When exploring the origins of NBS, it is imperative that credit is given to Indigenous peoples and traditional knowledge. Although Indigenous peoples compose just 5% of the global population, they protect an astounding 80% of Earth’s biodiversity. The concept of reciprocity, caring for the environment and gratitude for the life it sustains, is a central concept to many Indigenous belief systems. The first examples of NBS can be found in these communities in their harmonious existence with nature. NBS did not evolve in modern context until the 1970s with the concept development of ecosystem services. Since then, there has been an increasing push as to the importance of solving societal issues with natural solutions. Nature has a remarkable ability to self-regulate. Instead of fighting with our environment to control it, why not harness it and work in tandem with natural processes to benefit everyone?
NBS shows great promise in combating climate change impacts in communities everywhere. Data shows that NBS could provide 30-40% of all carbon dioxide mitigation to keep global warming under 2°C by 2030. The wide range of applicability also allows more flexibility in how communities respond to societal issues or climate threats through NBS. With dire predictions being reported by climate science groups such as the Intergovernmental Panel on Climate Change, there is a demand for rapid and effective infrastructure to mitigate and adapt to changing conditions. Those most vulnerable to the effects of climate change are often historically marginalized and impoverished communities, particularly those in coastal areas.
Small Island Developing States (SIDS) are unequivocally the most threatened areas for climate change impacts. These small landmasses are isolated from protection of larger geological structures and are exposed to numerous oceanic, atmospheric, and ecological catastrophes. SIDS are on the frontline for extreme weather, sea level rise, over-exploitation of resources, and biodiversity loss. Simultaneously, these communities often possess the fewest resources to be able to adapt to such issues as they have low economic diversity and are geographically isolated.
SIDS act essentially as mesocosms of larger global issues. The impacts are felt more severely as there is less area for them to be dispersed over. Already, many Pacific Islands are seeing significant effects of sea level rise, particularly coastal erosion. These areas are the most in need of rapid and effective application of NBS to sustain these communities as climate change impacts continue to increase. NBS solutions provide the added benefit of using locally sourced and native solutions, enhancing independence and a sustainable economy. This paper provides a case study review of effective NBS applications for global SIDS.
Greenville Bay, Grenada was experiencing significant coastal erosion and sedimentation that clogged vital navigation channels into the island. Mass dredging was used to remove sediments from channels to allow cargo ships to deliver supplies. Storm surge and flooding were becoming a major issue for coastal infrastructure. Wave energy modeling showed that the cause of the relatively sudden mass coastal erosion was barrier reef degradation. The previously healthy reef protected the bay from breaking wave energy, a problem that is becoming increasingly important with sea level rise. In 2015, the government of Grenada, the local community, and the Nature Conservancy developed a plan to restore the reef by installing artificial reef structures. The structures were designed based on wave energy modelling, measurements of the seabed, and collaboration with local knowledge. The resulting blocks were modular and porous to allow for easy installation and greater integration of coral and invertebrate species into the artificial reefs. The material for the blocks was locally sourced from an adjacent quarry and installed by local fishermen and divers. In addition, community members initiated a mangrove seedling nursery to replant previously eroded coastline.
While no official follow-up study has been done, the understood results of the project are the establishment of a carbon sink through mangrove reforestation as well as significant reduction in coastal erosion and flooding due to the artificial reef. 12 months after the initial installation, locals report observing substantial coral recruitment as well as diverse fish species, octopus, and lobster on the reef blocks. The final funding was approved to complete the project in June of 2022. The project requires low maintenance after installment. It is noted, however, that artificial reefs in the Caribbean tend to develop different biota than naturally occurring reefs and require fisheries maintenance.
Jeffrey Town, Jamaica’s soil’s agricultural capacity was being sorely overexploited. Deforestation and monoculture planting resulted in severe sedimentation, landslides, and erosion, as well as contamination of water supplies. In response, the Jeffrey Town Farmers Association was formed to promote sustainable agriculture and reforestation. The organization’s primary goal was education and training of locals to promote a generational attitude shift towards sustainability and NBS. They intended to develop climate resilient agricultural infrastructure while reducing food insecurity, soil nutrient depletion, and slash and burn farming. Workshops and demonstrations were done to teach farmers terracing of land, water harvesting, and organic growing. Emphasis was placed on placed on planting native fruit trees to increase tree cover which simultaneously increased food security and stabilized and revitalized soils. Drought resistant demonstration plots and practices were also created. Community incomes have increased due to a wider range of crop production and increased self-sufficiency amongst farmers due to education availability.
Port Salut, Haiti is one of the hardest hit countries by natural disasters, both hurricanes and earthquakes. The country is also extremely impoverished and lacks resources to respond and adapt to these events. Haiti is in desperate need of development of community and ecosystem resilience. The Cote Sud Initiative and the UN Environment Program developed a “ridge-to-reef” ecosystem-based disaster risk reduction plan. A “ridge-to-reef” plan is one that extends across the landscape to create a comprehensive resilience throughout the island. There were four main aspects to the action plan. First was revegetation and an alteration of agricultural practices from vetiver monoculture to reduce inland flooding and erosion. A similar effort was undertaken along the coast. Replanting of the coastal margin was completed to provide a biological buffer from storm surge and wave energy. A tree nursery was established to support revegetation efforts. The tree nursery produced 137,000 seedlings of coastal, riparian and fruit tree species. Locals were trained to operate the nursery and utilized it as a community education center. 54,065 fruit trees from the nursery reforested 141 hectares of land, and 36,300 mangrove and sea grape trees were used to stabilize coastline. Finally, improvements were made to fisheries practices to reduce strain on coastal fish populations. Construction and repair of fishing vessels were done such that they could travel further offshore so as not to overexploit inland diversity.
Following these efforts, Port Salut was established as Haiti’s first marine protected area. There has been a documented reduction in sedimentation run off and consequently a rebound of seagrass and coral reef health. The largest concern regarding this project is Haiti’s ability to continue the project. Without outside assistance and funding, Haiti does not have the capacity to sustain or enforce protections and sustainability efforts.
O’ahu, Hawaii strove to improve water quality and climate change resilience through protection and restoration of the He’eia wetlands. The wetlands are surrounded by agricultural land as well as the traditional ancient He’eia fishpond. The Indigenous people wished to protect the water flow entering the sacred fishpond and reinstate the more sustainable traditional agricultural practices in the surrounding land. The Nature Conservancy and local conservation group Kako’o ‘Oiwi, worked to restore the 8 streams that composed the wetland by limiting sediment and nutrient run off, removing invasive species, improving water flow, and promoting traditional agriculture. These efforts had a positive impact on water quality and stormwater management over 405 hectares. Biodiversity within the wetland increased with the establishment of native species. Similar to what was found in Haiti, reduced sedimentation showed an increase in coral and seagrass health which also improved fisheries production. The now thriving wetland also acts a nutrient and carbon sink. Local livelihoods were supported by the application of traditional agricultural knowledge that protected and maintained a healthy landscape.
Namdrik Atoll, Marshall Islands case study experiences some of the most direct impacts from climate change. Atolls are, by nature, very low-lying features. This makes them highly susceptible to flooding and erosion from sea level rise and wave energy. The Marshall Islands also endures highly variable weather conditions and an economy with high dependence on production from local fisheries. To resolve their many challenges, Namdrik Atoll had to find ways to diversify their economy, increase food security and safeguard their shoreline and natural resources. The Namdrik Atoll Resources Committee made several substantial steps to achieve this. An agricultural shift was made to increase growing of traditional polycultural fruits such as breadfruit, taro, and pandanus. This allowed the atoll to rely less heavily on food imports as well as protect soil nutrients and native habitat. A pearl farm was established to provide additional jobs and a source of income for the island. Seasonal no-takes were put in place to allow fisheries populations time to breed and recover from overexploitation. Shorelines were re-planted with native vegetation and freshwater harvesting techniques were improved.
This monumental effort on Namdrik Atoll has had great success in improving food security, increasing biodiversity, and providing a sustainable and diverse economy. Near-shore fish populations are thriving thanks to seasonal no-takes and re-vegetation with mangrove habitat. The replanting of trees had the unintended benefit of developing a wordcraft trade through the island, creating more jobs and revenue for the island. The pearl farm has also proven to be very lucrative.
Porto Santo Island, Portugal is a tiny mountainous island off the coast of west Africa. The island is exposed to extreme weather and wave action as sand bars provide minimal wave break to protect its beaches. The sand dune ecosystem is what the locals rely on for wind and wave protection. With sea level rise and severe storms, these dunes are rapidly eroding away. Using EU funding, the government of Portugal initiated a restoration of the sand dune ecosystem. 39,000 native trees were planted on and around the sand dunes to stabilize the substrate and invasive species were removed in a biological buffer area to preserve the dunes’ integrity. Strategically chosen sand bars were dredged and 90,000m3 of sand were re-added to the dunes. Sustainable agriculture techniques were implemented on the inshore side of the dunes to reduce risk of pollution and wind erosion. To demonstrate this, 19,000m of display plots were created to show how various planting techniques limit wind erosion. The most effective of these was the planting of vineyards. As an added improvement, the project provided critical nesting habitat for the endangered Kentish plover and established regulations for the preservation of endemic flora. The stately sand dunes are now regarded as a natural beauty and attract a bustling tourist industry which the island’s economy relies on.
Antongil Bay, Madagascar is the largest bay in the country and the most productive in the Indian Ocean. As a result, this ecosystem was under great fishing pressure and on the verge of collapse. Additionally, much of the bay’s natural mangrove habitat has undergone conversion into rice fields. In an extraordinary success story, the Collaborative Platform for Sustainable Development of the Antongil Bay created 20 locally managed marine areas within the bay and managed to establish a set of functional and enforceable regulations for more sustainable fishing. These designated areas have been so successful that studies showed a tenfold increase in fish biomass from 2013-2015. The organization also encouraged the planting of mucua, a nitrogen fixing plant to enrich soil health, promote forest management to control logging, and protect mangrove and coral habitats to strengthen climate resilience. Local income and food security improved through larger fish diversity, size, and abundance, and an increased interest in ecotourism.
Del Carmen, Philippines struggles with extreme poverty and few economic opportunities. As a result, many locals were forced to resort to ecologically damaging practices in order to feed their families. This included the cutting and selling of mangrove forests for firewood and construction. Del Carmen has the largest mangrove forest in the Philippines. In 2018, the forest covered 4,871 hectares. The mangroves also host many species of endemic plants and animals, protects unique marine, terrestrial and wetland habitats, and acts as a carbon sink. The destruction of the mangrove forest had immensely damaging impacts on fish populations and the ecological balance throughout the Philippines. Also, the mangroves serve as an effective storm barrier for the community as the island experiences strong and frequent typhoons. The Siagrao It Up conservation group sought to remedy this. Through the restoration and protection of mangrove forest, they have effectively reduced the cutting of this natural resource by 90%. This is also in large part due to their education program and offering former mangrove-cutters job opportunities as ecosystem stewards. Many these people have become fish wardens who monitor the protected area to enforce laws.
The restoration of the mangroves improved climate resilience by protecting freshwater sources for salinization, reducing erosion, and dispersing flooding. In tandem with this project, a Mangrove Management Plan was developed and fish and mangrove nurseries established. There are documented improvements to water quality, flood protection, coral habitat, flora and fauna diversity, job availability, and even lower crime rates.
Batticaloa, Sri Lanka’s city lies along its vulnerable coastline. Roughly 70% of Sri Lanka’s urban population resides along the coast and 80% of its economic infrastructure is in its coastal cities. This places the majority of Sri Lanka’s people and stability at great risk from climate change impacts. The effects of this are already being seen. In 2009-2010, Batticaloa experienced its largest flood in 100 years that inundated communities and compromised freshwater sources. To develop resiliency to multi-disaster situations, a multi-purpose 400 hectare green belt was built to protect the lagoon and coastal region of Batticaloa. The green belt is meant to bolster biodiversity and protect the beaches, coastline from sudden wind and wave changes, and strengthen the economy. The green belt was designed after consultation with the local community and many public review meetings were held. The project also ultimately reduced costs for urban management and provided tree cover for recreation.
Mahe and Praslin Islands, Seychelles is in a similar position to Namdrik Atoll in the Marshall Islands. Seychelles is an archipelago made of 115 low-lying islands north of Madagascar. The focus for this case study is the freshwater shortage and coastal erosion of the capital island Mahe and Praslin. The islands experienced severe flooding from sea level rise as well as changing precipitation patterns throughout the region. The Ministry of Environment and Energy of Seychelles initiated in 2012 an ambitious project aiming at improving the quality of life for the people of Seychelles and restoring coastal zones as well as the ecological habitat related to them through NBS. This was done through the rehabilitation of ecosystem services of watershed and coastal habitats to secure water provisioning and flood management. Degraded water catchment areas were restored, and reforestation of coasts collected freshwater and reduced risk of contamination. Wetlands were artificially created and naturally occurring ones were protected to filter nutrient and sediment wastes and ameliorate stormwater drainage. Protections were put in place for 70 endemic tree species and 50 hectares of bare ground and bush surrounding the watershed were revamped. Education and training workshops were implemented to ensure community involvement. Over several years, gabion rock barrages were built at seven locations as freshwater reserves. In 2018, 4,000 native trees were planted along the watershed. In 2019, a climate change curriculum was added to the school system to teach children about climate change impacts, specifically within Seychelles.
Most recently, Mahe began a “ridge-to-reef” project to run from 2020-2025. Their purpose is to raise conservation status of existing protected areas, reduce land-based impacts on marine environments, and develop a sense of responsibility for natural resources within the community while developing ecotourism.
As these case studies show, there is great potential for the application of NBS in a variety of formats to address a wide range of issues. Island ecosystems are small scale examples of climate issues that will arise on larger continent communities as climate change progresses. The success of these SIDS’ NBS programs shows hope for the application of NBS projects on larger scales to address similar issues. However, despite an increasing interest in NBS use as alternative adaptation methods, there are some key barriers to widespread acceptance. The U.S. Biden-Harris administration recently released a comprehensive guide to NBS politics and implementation. The barriers and areas in need of advancement in order to mainstream NBS are as follows:
- There must be updates to policies and procedures regarding NBS as an alternative solution to urban engineering. NBS should be incorporated into federal planning policies and permits and foremost considered in new infrastructure development. Federal policy should explicitly encourage the consideration of NBS options. Most importantly, a cost-benefit analysis of NBS must be developed to quantify NBS success and contribution as well as the potential pitfalls compared to other solutions.
- NBS should be prioritized in funding decisions for domestic and international solutions. Federal policies should subsidize and incentivize the use of NBS over other, more conventional solutions as well as encourage private investment. Funding allotment for NBS should be expedited and efficient to increase ease of access. Funding should be streamlined to ensure most effective use and allotment.
- Let federal facilities be the example. Incorporate NBS projects into government programs, facilities, and infrastructure. Manage federally controlled lands with prioritization of NBS in all solution proposals. Reclaim former projects to include NBS.
- Provide training and resources for those interested in NBS to expand the job market for this field within federal and private sectors. Encourage the sharing of ideas and various NBS solutions across all sectors and learn from international, Indigenous, and scientific knowledge. Federal assistance for NBS training and accessibility of information and tools must be enhanced. Make a cost-benefit analysis tool readily available to the public to highlight the efficacy and utility of NBS. Develop certifications for NBS specialties. Incorporate NBS into school curriculums and lesson plans.
- Complete more research on the usefulness and efficacy of NBS and how they contribute to our understanding of climate change and the ability to adapt. Knowledge gaps and discrepancies must be cleared. Engage with stakeholders and previous/current NBS projects to determine long-term outcomes. Determine to what scale NBS is most effective. Increase monitoring of NBS projects to quantify successes and pitfalls.
There is a great opportunity in the widespread application of NBS to address climate issues and societal challenges. Society has spent much of its time developing new technologies and innovations and has largely forgotten the marvel with which nature is capable of stabilizing itself. The climate crisis and its symptoms can be treated with returning what it is humans attempted to control in the first place. If instead of attempting to subdue nature, it is allowed to reclaim its equilibrium, there is much to be gained. The understanding of NBS as the solution to the climate crisis is rapidly disseminating. In the Paris Climate Agreement, it was formally recognized that natural resources provide services to human health and well-being and should be considered to meet climate goals. This is a very promising start to the future of NBS and our global community’s resilience to climate change.
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