Half of Global Mangroves Are at Risk of Collapsing, IUCN Warns

A new report from the International Union for Conservation of Nature (IUCN) has found that about half of all mangrove ecosystems in the world are at risk of collapsing, meaning they are considered vulnerable, endangered, or critically endangered by the organization’s Red List of Ecosystem standards.

Further, about 19.6% of mangroves, nearly one in five, are considered to be at severe risk of collapse, meaning they rank as endangered or critically endangered, the report found.

The IUCN Red List of Ecosystems measures the health and risks of specific ecosystems, but this is the first time the standards have been used to assess an ecosystem at a global scale.

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“The first global assessment of mangrove ecosystems gives key guidance that highlights the urgent need for coordinated conservation of mangroves — crucial habitats for millions in vulnerable communities worldwide,” Grethel Aguilar, IUCN director general, said in a press release. “The assessment’s findings will help us work together to restore the mangrove forests that we have lost and protect the ones we still have.” 

IUCN reported that mangrove ecosystems face an increasing number of threats, particularly from the effects of climate change. Frequent and severe weather events threaten the mangroves, but they are particularly vulnerable to sea level rise.

Mangrove ecosystems, which require tropical, humid environments, are expanding into temperate areas because of climate change. According to IUCN, agricultural use of freshwater has also limited the amount of freshwater that can reach coastal areas where mangroves typically thrive, limiting the mangroves’ ability to survive in their natural habitats.

But sea level rise remains the biggest threat to mangrove ecosystems, the report highlighted. In a business-as-usual scenario, about 25% of the global area covered by mangroves currently could be submerged over the next 50 years, and about 33% of global mangrove ecosystems will be severely impacted.

At the current rate, the predicted mangrove losses would lead to a loss of 1.8 billion metric tons of stored carbon emissions, equating to a cost to society of about $336 billion. Losing these mangrove ecosystems could also expose 2.1 million people to coastal flooding.

“Mangrove ecosystems are exceptional in their ability to provide essential services to people, including coastal disaster risk reduction, carbon storage and sequestration, and support for fisheries,” said Angela Andrade, chair of the IUCN Commission on Ecosystem Management. “Their loss stands to be disastrous for nature and people across the globe.”

The report, while grim, concluded with next steps to curb emissions and preserve these important ecosystems, which can store more carbon than tropical forests and protect over 15 million people from coastal flooding each year.

IUCN recommended efforts to preserve and restore mangrove forests as well as providing more inland space for the mangroves to naturally expand to adapt to sea level rise.

As NPR reported, humans will need to pursue ways to curb emissions and the effects of climate change to further protect these at-risk ecosystems, such as through a clean energy transition.

“The Red List of Ecosystems provides clear pathways on how we can reverse mangroves loss and protect these delicate ecosystems for the future, helping in turn to safeguard biodiversity, tackle the effects of climate change and support the realisation of the Global Biodiversity Framework,” Andrade said.