Mangroves: Essential Allies Against Climate Change
Learn how mangroves play an essential role in climate change mitigation and biodiversity, providing coastal protection and supporting local economies.
The Editors·
Learn how mangroves play an essential role in climate change mitigation and biodiversity, providing coastal protection and supporting local economies.
This article is part of Global Geneva’s Focus on Oceans series.
Mangrove forests have a special place in my heart, making the work I have done on this ecosystem very personal and rewarding. Between university years, I did field work in the so called “mosquito-ridden and muddy” mangroves of northern Madagascar and absolutely loved it.
The soothing scent of rich silt is the prevailing aroma of the mangroves, and the mud provides an excellent and free spa treatment. Furthermore, numerous marine species, including fish and shrimp, are known to use the shelter provided by mangroves as nurseries while they mature. They feed on leaf scraps and microorganisms, all the while hiding from predators in the thick tangles of roots.
Due to the alien and unusual characteristics of the mangroves, I found my attention constantly divided between appreciating the trees and their intertwined roots and marvelling at the vibrant world of crabs and mudskippers living under and above the surface. Knowing that mangrove populations are dwindling, my feelings were bittersweet as I moved through this beautiful ecosystem.
Thank goodness, however, I am not the only one who finds these forests amazing and valuable. These dynamic ecosystems provide approximately US$33-57K per hectare per year of income to national economies in services such as coastal protection, food and medicines. According to UN estimates, over 100 million people live in proximity to mangroves. Furthermore, although this ecosystem covers less than 1% of our planet’s surface, it can offer substantial benefits in climate change control. For example, a 10km2 area of mangrove forest can store the same amount of carbon as 50km2 area of tropical upland forests.
Unfortunately, however, mangroves are disappearing three to five times faster than global forest losses, and annual carbon emissions resulting from mangrove loss have been calculated to exceed the carbon emissions from the whole of Austria. All the more reason to preserve this ecosystem.
Other ecosystems play similar roles in temperate regions: salt marshes and seagrass meadows, for example. It is estimated that under the right conditions, these ecosystems can store even more carbon than mangroves. When found together, healthy mangroves, seagrass, marshes and coral reefs support each other in offering higher biological productivity and benefits for people dependent on these resources and for biodiversity despite the imminent threat of climate change.
Why else do we need mangroves? The answer stems from their resilience. Disaster Relief and Reduction (DRR) is a growing issue brought to light by the increasing frequency of powerful cyclones like Idai and Kenneth. They wreaked havoc across the Western Indian Ocean region early in 2019, severely affecting nations like Mozambique and Zimbabwe.
A belt of mangroves 100 metres thick has the ability to reduce wave height by two thirds, greatly reducing the damage to an area. On top of that, a cost analysis from the Philippines showed that the protection provided by mangroves was not only less expensive than erecting a seawall (without mentioning maintenance costs), but also provided local communities with fisheries-related benefits (e.g. acting as nursery grounds for different species) worth over US$170,000. In the same country, one hectare of mangroves is estimated to save US$3200 per year in flood prevention benefits.
Unfortunately, mangroves have declined by 35% compared to their pre-1980 global coverage, largely because of land conversion and overexploitation. Losses are extremely high in South-East Asia, the Caribbean and the Pacific. While the loss rates are now slowing due to the increased recognition and awareness of mangrove benefits, the global rate of loss continues at approximately 1% per year. Lack of sustainable financing is often cited as a reason for long-term project failure in mangrove protection. Those who lose out the most are local communities who depend on the mangroves for their livelihoods and the biodiversity living within these forests.
Studies by Save Our Mangroves Now!, a project jointly implemented by the IUCN, WWF-Germany, and funded by the German government, show that often overlapping jurisdictions and a lack of coordination within government ministries cause inefficiencies and conflict. Experience tells us that community participation should be key to effective implementation and enforcement, since the primary users (locals) tend to have the greatest motivation to manage their ecosystem.
Nature-based solutions are increasingly recognized as the preferred approach to meet the needs of people and the environment in addressing climate change risks. Several international institutions, including the European Union, now have programmes and projects adopting this approach, and IUCN has been active on this front for many decades.
Running from 2006 to 2018, the programme Mangroves for the Future (MFF), based in Bangkok, Thailand, but chaired by IUCN and the United Nations Development Programme (UNDP), put its focus on building resilient coastal communities in 11 Asian countries by taking account of all the relevant marine ecosystems.
More than 140 projects were completed using its partnership approach, benefiting more than 300,000 people, IUCN reports. Three-quarters of the projects were implemented by community-based organizations or local NGOs. Climate change and disaster risk reduction were major themes of the initiative. Its activities were largely funded by Norway and Sweden, and IUCN said the lessons learned from the 12-year engagement will be used to help coastal communities to keep their ecosystems healthy for sustainable development. Similarly, Germany supports about 40 projects in more than 15 countries, receiving global support from Save Our Mangroves Now!
Raphaelle Flint is Marine Programme Officer for IUCN’s Global Marine & Polar Programme in Gland, Switzerland.
22 June 2020. Scientists find mangrove collapse is ‘inevitable’ unless greenhouse gas emissions are curbed. (LINK)
25 September 2019. IPCC Special Report on Oceans and the Cryosphere. (LINK). World Oceans Forum: “The report suggests aggressive adaptation efforts to help coastal and inland communities: better fisheries management, mangrove protections, adaptation for storm surge and coastal flooding, and increased investments in early warning systems to predict natural disasters” (LINK)