How planet's 'blue forests', mangroves, protect coastlines, support wildlife and store up to four times more carbon than tropical rainforests

Mangrove forests occupy only a tiny fraction of Earth’s land surface, yet they are among the planet’s most valuable ecosystems. Growing where land meets the sea, these salt-tolerant trees form dense coastal forests that shield shorelines from storms, provide nurseries for marine life and lock away enormous amounts of carbon. Their exceptional ability to capture and store carbon has earned them the nickname “blue carbon forests”, making them one of nature’s most powerful allies against climate change. Scientific research from The University of Queensland shows that mangrove ecosystems can sequester around four times more carbon than terrestrial forests. As the world marks World Mangrove Day, scientists are drawing renewed attention to these extraordinary ecosystems, whose ecological importance extends far beyond the coastlines they inhabit, supporting biodiversity, protecting coastal communities and playing a critical role in regulating Earth’s climate.

Why mangroves are among Earth’s most powerful natural climate defenders

Mangrove forests are among the world’s most effective natural coastal defence systems because they simultaneously reduce flood risk, stabilise shorelines and store vast amounts of carbon. Their dense networks of aerial roots dissipate wave energy, trap sediments and slow storm surges before they reach inland communities, while their waterlogged soils accumulate large quantities of organic carbon over centuries. The research found that mangroves prevent more than US$65 billion in flood damage every year and protect over 15 million people from coastal flooding. The study also showed that removing existing mangrove forests would increase annual flooding by around 29% more land area, 28% more people and 9% more property, highlighting that these “blue forests” are not only biodiversity hotspots but also critical natural infrastructure for climate adaptation and disaster risk reduction.

Earth’s most powerful carbon sinks: Science explained

Although mangrove forests cover less than one per cent of the world’s tropical forests, they store disproportionately large amounts of carbon. Unlike most terrestrial forests, mangroves capture carbon not only in their trunks and branches but also deep within oxygen-poor coastal soils, where organic material can remain buried for centuries or even millennia.A study ‘The global flood protection benefits of Mangroves’ published in Scientific Reports, found that mangrove ecosystems represent some of the most efficient long-term carbon sinks on Earth. By slowing the decomposition of organic matter in waterlogged soils, they can store three to four times more carbon per unit area than many tropical forests, making their protection critical for limiting greenhouse gas emissions.The research, conducted by Daniel Murdiyarso, J. Boone Kauffman, Matthew Warren, Sigit Sasmito, Donato C. Donato, Shuichi Manuri, Heri Purnomo and Sonia Kurnianto, highlights how conserving mangroves delivers climate benefits that extend far beyond coastal regions.

A lifeline for wildlife and coastal communities

Mangroves are more than carbon reservoirs, they are biodiversity hotspots. Their tangled roots provide shelter for juvenile fish, crabs and shrimp, many of which later populate offshore reefs and fisheries. Numerous birds, reptiles and mammals also depend on mangrove habitats during different stages of their lives.Globally, mangrove ecosystems support many threatened species, while their dense root networks act as natural barriers against storm surges, coastal flooding and erosion. By absorbing wave energy before it reaches land, mangrove forests reduce the impact of tropical cyclones and help protect millions of people living in vulnerable coastal regions.For many coastal communities, healthy mangroves also underpin local economies by sustaining fisheries, supporting ecotourism and improving water quality.

Protecting one of Earth’s most valuable ecosystems

Despite their immense ecological and economic value, mangrove forests continue to disappear because of coastal development, aquaculture, pollution and climate change. According to the United Nations Environment Programme (UNEP), more than half of the world’s mangroves have already been lost or degraded in many regions, threatening biodiversity, fisheries and the natural protection these forests provide against storms and rising seas. UNEP emphasises that conserving existing mangroves is far more effective than attempting to recreate them once they have been destroyed, as mature forests take decades to recover their full ecological functions. Alongside restoration projects, protecting remaining mangrove habitats through sustainable coastal planning and community-led conservation is considered one of the most cost-effective nature-based solutions for strengthening climate resilience, supporting livelihoods and safeguarding vulnerable coastlines for future generations.