A major environmental assessment has recorded the first sustained global increase in mangrove forest cover in half a century, reversing a trajectory of destruction that has alarmed climate scientists and conservationists. Data compiled by the Global Mangrove Alliance, a consortium of research institutions and non-governmental organisations, indicates net growth of approximately 3,000 square kilometres between 2015 and 2023.
The findings, published in the journal Nature Ecology and Evolution, represent a marked departure from previous decades. Between 1970 and 2015, mangrove cover declined by an estimated 35%, driven by coastal development, aquaculture expansion, and timber extraction. The reversal is concentrated in Southeast Asia, West Africa, and parts of Latin America, where national restoration programmes and improved coastal governance have taken effect.
Indonesia, which holds roughly one-fifth of the world’s mangroves, contributed the largest gains. Government-led restoration projects, combined with community-managed conservation zones, added 1,200 square kilometres. Similar initiatives in Vietnam, Thailand, and the Philippines have helped stabilise coastlines that were heavily damaged by shrimp farming and urbanisation.
Mangroves are recognised as highly effective carbon sinks, storing up to four times more carbon per hectare than tropical rainforests. Their root systems also protect shorelines from storm surges and erosion, and provide critical nursery habitats for fish and crustaceans. The International Union for Conservation of Nature estimates that restoring mangroves could sequester an additional 0.5 gigatonnes of CO2 annually by 2050.
Despite the positive trend, scientists caution that the gains remain fragile. Continued threats from rising sea levels, agricultural runoff, and industrial infrastructure projects could reverse the recovery. The assessment notes that annual mangrove loss rates in some regions, particularly Myanmar and Madagascar, remain high. Restoration success also depends on replanting appropriate species and ensuring hydrological connectivity, rather than simple monoculture plantations.
The Global Mangrove Alliance has called for increased international funding to expand restoration and enforcement efforts. The coalition’s target is to increase global mangrove cover by 20% from current levels by 2030. The latest data suggests that this benchmark, while ambitious, is achievable with sustained political will and community engagement.
The announcement comes ahead of the United Nations Climate Change Conference, where coastal ecosystem restoration is expected to feature prominently in national carbon mitigation pledges. The reversal in mangrove decline offers a rare positive signal in an otherwise bleak landscape of biodiversity loss and climate disruption, though experts urge against complacency.
