Mangroves store ‘blue carbon’ - but they’re disappearing fast

MANILA - Blue carbon - a magic ingredient found in mangroves and salt marshes - is worth billions as a natural shield for nations that are most vulnerable to floods, storms and climate change.

But those same countries are struggling to unlock funds to protect their natural marine and coastal defences, leaving millions at risk of the deadly fallout from climate change.

So what is blue carbon, where is it found and how do countries come up with the cash to preserve it?

What is blue carbon?

Blue carbon refers to the carbon captured and stored by mangroves, salt marshes and seagrasses found along the coastlines of every continent except Antarctica, covering about 49 million hectares.

These critical natural assets are known to be more efficient than tropical rainforests at storing large, planet-heating carbon stocks called "blue carbon" from the atmosphere.

If traded on carbon markets, all the blue carbon that is stored in the world's marine and coastal ecosystems would be worth up to $190 billion a year, according to the World Bank.

Why is it under threat?

Island nations face significant challenges in financing the long-term conservation of their blue-carbon ecosystems.

An estimated 340,000 to 980,000 hectares of coastal, blue-carbon ecosystems are destroyed each year and about two thirds of all mangroves have already gone, according to

The Blue Carbon Initiative, which conserves and restores coastal ecosystems.

Studies show blue-carbon ecosystems are threatened by shrimp farming and palm oil production, infrastructure expansion, illegal deforestation and pollution.

If protected and restored, the ecosystems and their cache of blue carbon could help countries hit their climate goals, according to the World Economic Forum (WEF).

In 2023, the WEF launched a Blue Carbon Action Partnership, seeking investments to protect mangroves, salt marshes and seagrass meadows.

The Philippines and Indonesia - which house a combined 4 trillion tons of carbon in their blue-carbon ecosystems - joined the partnership in 2023, and have since drafted plans to safeguard their coastline ecosystems.

Why is Southeast Asia so critical?

Almost a third of mangroves are found in Southeast Asia, with nearly 20% of the world's mangroves in Indonesia alone.

Tropical countries rely on mangroves and other blue-carbon ecosystems to shield them from floods, storms and rising seas, as well as to safeguard their food production and ecotourism.

Of the region's 4.7 million hectares of mangrove forests, roughly half could be eligible for carbon finance, according to a study in the Communications Earth & Environment journal.

Yet 85%, or 1.8 million hectares, of the mangroves eligible for carbon credit investments are at risk of destruction, mainly due to the cultivation of palm oil, rice and aquaculture.

How can countries finance their protection?

An estimated $4 billion is needed by 2030 to protect the world’s blue-carbon ecosystems, according to the Global Mangrove Alliance, an initiative set up to reverse their decline.

The group envisions that about a third of this funding will come from private sources, while the rest can be covered by philanthropic, development and public finance.

But the alliance also said the private sector is falling short, leaving governments and philanthropists to pick up most of the bill.

What are the obstacles?

The Philippines is struggling to unlock finance as many of its mangroves have already been converted to aquaculture, fish ponds and salt farms.

The country also faces disputes over who owns the carbon credits in a given area, and high transaction costs.

Indonesia fell short of its target to restore 600,000 hectares of mangroves by 2024 – restoring only 25% - due to budget constraints and conflicts in land ownership.

(Reporting by Mariejo Ramos. Editing by Lyndsay Griffiths.)