Conserving and restoring Southeast Asia's carbon-rich peatlands and mangroves could mitigate more than 50 per cent of the region's land-use carbon emissions, according to a new international study published in Nature Communications.
Despite occupying just 5 per cent of the region's terrestrial land, these ecosystems play an outsized role in emission reduction efforts, making them crucial for meeting climate targets across ASEAN countries.
The research study, conducted by an international team of scientists from NUS, with contributions from Nanyang Technological University, Singapore (NTU Singapore) and James Cook University in Australia, highlights the significant climate benefits of conserving and restoring peatlands and mangroves.
Together, these ecosystems store more than 90 per cent of their carbon in soils rather than vegetation, making them among the most efficient natural carbon sinks globally.
However, when disrupted or destroyed through activities such as land-use changes, these ecosystems release significant amounts of carbon into the atmosphere, posing a major challenge to achieving emission reduction targets.
Additionally, peatland degradation during dry periods, such as those associated with El Niño events, not only results in massive carbon emissions but also contributes to regional haze events, affecting air quality in countries including Singapore.
Associate Professor Massimo Lupascu, Principal Investigator and the paper's senior author, explained, "If we conserved and restored the carbon-dense peatlands and mangroves in Southeast Asia, we could mitigate approximately 770 megatonnes of CO2 equivalent (MtCO2e) annually, or nearly double Malaysia's national greenhouse gas emissions in 2023."
"Our research underscores the immense climate benefits of protecting these ecosystems, making them a pragmatic and effective natural climate solution for ASEAN countries," said Assoc Prof Lupascu, who is from the Department of Geography at the NUS Faculty of Arts and Social Sciences.
Professor David Taylor, a co-author of the paper and Head of the NUS Department of Geography, said that "including both peatlands and mangroves in the new Nationally Determined Contributions (NDCs 3.0) that countries signed up to the Paris Agreement must update and re-commit to every five years can certainly contribute to increasing the ambition of countries across the region through the setting of higher emissions reduction targets, although this would involve substantial investment in effective conservation and restoration"."
Unique ecosystems with global implications
Southeast Asia is home to some of the world's largest areas of tropical peatlands and mangroves. These ecosystems share water-saturated, oxygen-limited soils that slow the decomposition of organic matter, enabling them to act as natural carbon sinks when undisturbed.
However, this soil-stored carbon is "irrecoverable", meaning it cannot easily be replaced once lost to human activities, such as agriculture or urban development.
Assistant Professor Pierre Taillardat, a co-author of the paper and principal investigator at the Wetland Carbon Lab at the Asian School of the Environment, NTU Singapore, emphasised the transformative potential of wetland conservation and how it can also yield economic benefits through schemes like carbon credits.
"Wetland soils may have little agronomic value, as it is generally not well-suited for traditional farming or crop cultivation, but they are unmatched in their ability to store and preserve carbon," added Asst Prof Taillardat.
"If carbon were valued like other critical commodities, such as being traded on the carbon credits market, it could unlock vast opportunities for conservation and restoration projects. This will enable local communities to lead carbon management efforts with a win-win scenario where livelihoods and sustainable ecosystems thrive together."
Updated Emissions Estimates and Pathways for Change
The study also provides up-to-date estimates of emissions from disturbed peatlands and mangroves across Southeast Asia from 2001 to 2022, broken down by land-use type and country.
By doing so, it offers policymakers critical data to identify hotspots for intervention and prioritise conservation efforts.
In their paper, the researchers call for ASEAN governments to integrate peatland and mangrove conservation into national climate strategies.
Given their high carbon storage capacity and the ability to mitigate land-use emissions, peatlands and mangroves represent a cost-effective and impactful approach to achieving net-zero targets.
By conserving and restoring these ecosystems, Southeast Asian nations can reduce emissions, bolster climate resilience, and support local communities that depend on wetlands for their livelihoods.
Dr Sigit Sasmito, from TropWATER, James Cook University in Brisbane, Australia, who is the study's first author and led the work when he was a Research Fellow in the NUS Department of Geography, remarked, "By investing in the conservation of peatlands and mangroves, Southeast Asia can lead the world in deploying cost-effective, nature-based solutions that deliver enduring climate and biodiversity benefits. These ecosystems pack a climate mitigation punch far beyond their size, offering one of the most scalable and impactful natural solutions to combat the planet's climate crisis."
The open-access paper, titled "Half of land use carbon emissions in Southeast Asia can be mitigated through peat swamp forest and mangrove conservation and restoration", is available online at Nature Communications.
