Pulse Brain · Growing Health Evidence Index
Tier 1 — Meta-analysis / systematic reviewPeer-reviewed

Half of global methane emissions come from highly variable aquatic ecosystem sources

Judith A. Rosentreter, Alberto Borges, Bridget R. Deemer, Meredith A. Holgerson, Shaoda Liu, Chunlin Song, John M. Mélack, Peter A. Raymond, Carlos M. Duarte, George H. Allen, David Olefeldt, Benjamin Poulter, Tom J. Battin, Bradley D. Eyre

Nature Geoscience · 2021

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Summary

This Nature Geoscience meta-analysis synthesises evidence that aquatic ecosystems—including lakes, rivers, reservoirs, and wetlands—contribute approximately half of global methane emissions, with substantial variability depending on ecosystem type, climate, and hydrological conditions. The work integrates field measurements and modelling across multiple aquatic environments to characterise their role in the global methane cycle, challenging previous understanding of emission sources. The findings underscore the importance of aquatic systems in climate forcing and the need for improved emission accounting in climate models and policy frameworks.

UK applicability

The UK's extensive network of freshwater systems (lakes, rivers, wetlands, and reservoirs) may contribute significantly to national methane budgets; these findings support the case for including aquatic ecosystem emissions in UK greenhouse gas inventories and wetland restoration planning. However, UK-specific emission factors and regional variability would require country-level assessment.

Key measures

Global methane emission flux estimates (likely in Tg CH₄ year⁻¹ or equivalent); proportion of total anthropogenic and natural methane budget; variability across ecosystem types and geographic regions

Outcomes reported

The study quantified methane emissions from aquatic ecosystems (lakes, rivers, reservoirs, wetlands) and estimated their contribution to total global methane emissions. The research characterised the spatial and temporal variability of these emissions across different aquatic ecosystem types.

Theme
Climate & resilience
Subject
Climate & greenhouse gas mitigation
Study type
Meta-analysis
Study design
Meta-analysis
Source type
Peer-reviewed study
Status
Published
Geography
Global
System type
Other
DOI
10.1038/s41561-021-00715-2
Catalogue ID
SNmoi1q7ci-rgzu5n

Topic tags

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