On the International Day for Biodiversity, a landmark assessment by the International Union for Conservation of Nature (IUCN) has revealed alarming statistics about the health of mangrove ecosystems worldwide. For the first time, an ecosystem group has been evaluated entirely across the planet using the IUCN Red List of Ecosystems, a global standard for measuring ecosystem health.
The findings shows that 50% of the assessed mangrove ecosystems are at risk of collapse, categorized as either Vulnerable, Endangered, or Critically Endangered. Notably, nearly 20% (19.6%) of these ecosystems are classified as Endangered or Critically Endangered, highlighting a severe risk of collapse.
Mangroves face a plethora of threats, including deforestation, development, pollution, and dam construction. However, the growing risk is primarily driven by climate change, manifesting as sea-level rise and the increased frequency of severe storms. The assessment indicates that climate change threatens one-third (33%) of the mangrove ecosystems evaluated.
The study, led by IUCN with the collaboration of over 250 experts from 44 countries, classified the world's mangrove ecosystems into 36 regions, known as provinces. Each region's mangroves were assessed for threats and risks of collapse. This extensive work involved multiple research institutions, including the IUCN Commission on Ecosystem Management, the IUCN Species Survival Commission, and the Global Mangrove Alliance.
The assessment projects severe consequences if significant changes are not implemented by 2050. Climate change and sea-level rise could result in the loss of 1.8 billion tonnes of carbon stored in mangroves, currently valued at a minimum of $13 billion in voluntary carbon markets. This loss equates to a societal cost of $336 billion based on the social cost of carbon. Additionally, it would eliminate protection for 2.1 million people currently shielded from coastal flooding, representing $36 billion in property protection. The fishing industry would also suffer, losing 17 million days of fishing effort annually, a 14% reduction from current levels.
The assessment underscores the critical role of maintaining mangrove ecosystems in mitigating climate change impacts. Healthy mangroves are better equipped to cope with sea-level rise and provide inland protection against hurricanes, typhoons, and cyclones. Preserving existing mangroves and restoring lost areas can enhance their resilience. Ensuring sediment flows and allowing space for mangroves to expand inland are crucial for helping these ecosystems adapt to rising sea levels.
The findings of this assessment will guide future national assessments and actions to protect and restore mangrove ecosystems. The results are vital for realizing global commitments like the Mangrove Breakthrough, which aims to secure the future of 150,000 square kilometers of mangroves. Maintaining ecosystem integrity is essential for enabling mangroves to withstand climate change impacts. Stakeholders can use the information from the Red List of Ecosystems assessment to identify the most pressing threats in their regions and choose the best restoration strategies.
The IUCN's Red List of Ecosystems, established in 2014, serves as a crucial tool for tracking and reversing biodiversity loss, aligning with the Kunming-Montreal Global Biodiversity Framework. This framework provides a global standard for evaluating the conservation status of environments at various scales, facilitating the assessment and monitoring of ecosystem health and threats, and suggesting measures to mitigate biodiversity loss.
This comprehensive assessment highlights the urgent need for global action to preserve mangrove ecosystems, which are not only critical for biodiversity but also for their role in protecting coastal communities and mitigating climate change.
(Data Source: IUCN)
