How nature-based solutions can help fight climate change
Every year, more than 50 million migratory waterbirds fly to the opposite ends of the earth, using a major flyway, comprised of a network of wetlands. This migratory bird path extends across 22 countries from Alaska and the far east of the Russian Federation, southwards through East Asia and Southeast Asia, to Australia and New Zealand.
The East Asian–Australasian Flyway is now considered the most threatened of the world’s eight major bird migratory flyways due to the large-scale loss and degradation of its coastal, intertidal wetland habitats.
Wetland areas along the flyway have shrunk by about 50% in the People's Republic of China, 40% in Japan, 60% in the Republic of Korea, and 70% in Singapore.1 In Southeast Asia, up to 45% of inter-tidal wetlands have already disappeared, and about 80% of the remaining wetlands are threatened.2
Wetlands are vital for climate mitigation because they help regulate flood waters and sequester carbon.
Wetlands along the flyway are also economically important as they provide critical ecosystem services to nearly 200 million people in Asia and the Pacific—from food and water to building materials, medicines, recreation, water purification, and other benefits.
Solutions that deliver for people, nature, and the climate
Nature-based solutions (NBS) are a beneficial approach in protecting endangered ecosystems while addressing climate risks.
Defined by the International Union for Conservation of Nature as “actions to protect, sustainably manage, and restore natural or modified ecosystems,” nature-based solutions “address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits.”
Given their potential benefits, ADB has been deploying nature-based solutions as part of initiatives that combine grey and green solutions with soft measures such as awareness raising, policy making, land use planning, and early warning.
One ADB-supported initiative is developing a long-term plan to protect the East Asian–Australasian Flyway, with nature-based solutions as the centerpiece in a bid to deliver benefits for people and nature, while also ensuring resilience against climate change.
ADB established the initiative with the East Asian–Australasian Flyway Partnership and BirdLife International. The initiative seeks to mobilize $3 billion in innovative and blended financing over the next 10 years for ADB’s developing member countries along the flyway.
Nature-based solutions in wetlands provide efficient, inclusive, and proven interventions—ensuring the protection of habitats and species while also supporting communities and delivering climate co-benefits.
Interventions being eyed to protect the flyway’s wetlands include habitat restoration, rehabilitation, disaster risk reduction, reforestation, regeneration, and plantation. Mangrove restoration based on best practices can also help ensure food security, ecotourism, and other income-generating opportunities. There are also plans to drive communities to more sustainable aquaculture and fisheries practices to deliver long-term sustainable food security and improve nutrition.
Reducing flood risks, protecting people
The Philippines is also turning to nature-friendly solutions to mitigate flood risks in six river basins across the country. ADB is supporting the government in deploying nature-friendly solutions that respect river dynamics and ecosystem functions to reduce damage and keep vulnerable communities safe.
Such measures are essential as the Philippines has frequently suffered from annual flooding and landslides, mainly caused by typhoons, which have brought heavy losses to the country’s economy and claimed hundreds of lives every year.
Flood control civil works have been the primary focus of flood risk management. These emphasize evacuating flood water as quickly as possible or storing it temporarily by building dikes, floodways, and reservoirs. However, it is increasingly recognized that flood control infrastructure alone is not ideal for flood risk management. Conventional gray infrastructure cannot completely prevent flooding, and it may create inequalities and contribute to ecological degradation.
More comprehensive approaches that integrate flood prevention and mitigation with flood preparedness, which combine structural and nonstructural measures, including more nature-based approaches, are needed. These approaches include the planting of mangroves to improve protection against coastal flooding and taking measures to deflect extreme and damaging flows.
The use of such solutions is being piloted in the Apayao–Abulog and Abra river basins in Luzon; Jalaur in Visayas; and Agus, Buayan–Malungon, and Tagum–Libuganon in Mindanao.
The government hopes the projects could serve as models for potential replication and upscaling in other river basins in the country.
Ensuring cities’ resilience
Viet Nam is also deploying nature-based solutions to build the climate-resilience of its cities. Under an ADB-supported project, the country will develop small-scale, green, and climate-resilient infrastructure in the cities of Hue, Ha Giang, and Vinh Yen to strengthen socioeconomic development. The project was designed in support of the green cities action plans developed for each city with ADB support.
The initiative enables cities to respond to environmental degradation, inefficient resource consumption, inequitable growth, and increased risks of climate change and natural disasters.
The goal for Hue, an international tourism destination, is to make economic growth more sustainable.
Hue’s tourism offerings have room for further development, and some key attractions need greater investment and rehabilitation. Nature-based solutions could entail building a network of green spaces and other environmental features and technologies to better ensure the sustainability of the city and its heritage.
Building such “green infrastructure” uses vegetation, soils, and natural processes to manage water, temperature, and air quality to create healthier, resilient, and beautiful urban environments. Examples of “green” infrastructure include green roofs and walls, hard and soft permeable surfaces, green streets, urban forestry, and green open spaces such as parks, wetlands, and green drainage corridors. Green infrastructure also includes a wide range of green technologies for adapting and complementing buildings and infrastructure to be more efficient, and to better cope with heat, floods, and storms, which have become more frequent due to climate change.