Methanotrophs.
Sinking Methane NaturallyHow New Zealand's Farming Model is a Climate Solution Hidden in Plain Sight.
New Zealand isn’t just managing land—it’s stewarding one of the planet’s most effective, but overlooked, natural climate-regulating systems.
Across the country’s nearly 10 million hectares of permanent pasture, undisturbed soils are acting as a significant biological sink for atmospheric methane (CH₄), thanks to specialised bacteria known as methanotrophs. These microbes consume methane as their primary energy source. These microorganisms are particularly abundant in undisturbed, healthy soils, such as those found in permanent pastures and native grasslands and native forests.
Globally, these microbes form the largest biological sink for methane.
Emerging science reveals that low-input farming systems—like NZ’s grass-fed model—actively enhance these methane-consuming bacteria. Alarmingly, this free, planet-cooling service is excluded from official climate accounting due to NZ's use of IPCC’s outdated 2006 framework.
Methanotrophs: Earth’s Invisible Methane Vacuum Cleaners
Fact; soil methanotrophs represent the largest biological sink for methane.
According to Soil Methanotrophy Model (MeMo v1.0): a process-based model to quantify global uptake of atmospheric methane by soil, and noted in Global Methane Budget 2025, this suggests soil sink has more than doubled since 1900 and may double again by the end of the 21st century driving greater diffusion into soils. if we maintain healthy habitats for them to grow.
This methane sink is not static. It responds dynamically to soil health, disturbance, seasonal flux and microbial habitat—and New Zealand’s conditions are uniquely favourable.
The estimates for Soil methanotrophs consumption of methane is anywhere between 15–51 Tg CH₄/year, (teragrams) with an internationally accepted average 32Tg in IPCC 2021 . IPCC AR6 (2021). The uncertainty of figures, stems from the immense diversity of soil types, land management practices, climate conditions, and incomplete knowledge of methanotroph identification, distribution and activity.
In Laboratory testing, some methanotrophs seem to have NO clear saturation limit, the more methane available, the methanotrophs consume, this was in part confirmed by soil testing at Taupo's landfill in the early 2000's, where volcanic soils and high methane concentrations resulted in abundant, highly active population of 'super methanotrophs', leading to exceptionally high methane sink rate.
Highly active methanotrophs in Aotearoa's geothermic areas sink 17.4 μmol CH₄ gram day ≈ 132,000 kg CH₄ per ha per year in comparison to heathy pastural soils at 3-6kg CH₄ per ha per year and Aotearoa's beech forest soils reported in paper, Pristine New Zealand forest soil is a strong methane sink, 2004, a 17 month study showed a methane sink of 10-17 kg CH₄ per ha per year (2-6 times the northern hemisphere forest average).
While specialised soils in high-methane environments support extremely active methanotrophs, pastoral soils rely on high-affinity microbes that consume trace atmospheric methane—a much slower, diffusion process. It becomes obvious why most methanotroph research in New Zealand has focused on patented bio-filters for industrial mitigation, rather than on maximising methanotroph potential in NZ lo-input pastoral and forest systems.
Nevertheless, New Zealand’s healthy, undisturbed pastures appear to maximise this natural uptake.
New Zealand's Hidden Climate Powerhouse:
Soil and Stewardship.
NZ’s soil diversity drives unparalleled methane oxidation:
The foundation lies in New Zealand's diverse soils and their capacity as methane (CH₄) sinks. South Island uplands, are typical of soils renowned for rich methanotrophic bacteria thriving in balanced moisture conditions. Crucially, volcanic soils in the North Island, demonstrate "super" methane uptake due to unique aeration and microbial communities. Equally vital are native forest podzols further amplify this sink. Other soils respond dynamically to land management practices, maximising methanotrophic habitat potential. Coastal clay plains balance moisture, warmer temperature and microbial life, enabling year-round methane uptake through careful management. NZ’s unique restiad peat, a massive carbon sink, can even retain oxidation capacity under careful pastoral use.
New Zealand's Conservation Land of 8.6 million hectares, 32% of the country's land area. Pastoral Farmland covering 9.5 million hectares, around 39-40% of the total land area. This Includes Native Forests of 8 million hectares, with 2.8-1.4 million hectares of natives on private sheep and beef farms alone, (figures: more or less)
Yet, despite its scale and dynamism, this methane-consuming service is entirely excluded from New Zealand’s official greenhouse gas (GHG) inventory..
NZ’s Low-Input Farming: A Methanotroph Powerhouse
Why NZ’s Low-Input Farming Boosts Methanotrophs:
New Zealand's extensive pastoral systems—characterised by rotational grazing, no tillage, lo-inputs, and permanent pastures—create ideal conditions. Methanotrophs thrive in undisturbed soils with high organic matter and biodiversity, conditions that are actively promoted in low-input farming.
Evidence from Studies:Lo-Input, Undisturbed Systems, Permanent Grasslands:
act as net methane sinks, especially when undisturbed. A comprehensive review by Knief (2015) in Environmental Microbiology confirms upland soils, such as grasslands, are among the most significant methane sinks, and their capacity increases with reduced disturbance and higher biodiversity and stable soil structure—all hallmarks of New Zealand’s low-input sheep and beef farms.
Meta-analysis of 253 sites shows the impacts of ecological restoration on greenhouse gas emissions, from 2024, findings reveal that forest and grassland restoration increase CH4 uptake by 90.0% and 30.8%, respectively, mainly due to changes in soil properties.
Rotational Grazing Strengthens the Sink:
in a study "Adaptive Multi-Paddock Grazing Lowers Soil Greenhouse Gas Emission Potential by Altering Extracellular Enzyme Activity": The Research comparing rotational grazing (frequent rotations, high stock density, long rest periods) with conventional systems shows:
Methane sink was 1.5 times greater in soils from rotational grazed than conventional grazed grasslands.
While CO₂ respiration was slightly higher in Rotationally grazed soils at 5°C (+17% – indicating active carbon cycling), net greenhouse gas emissions were 22% lower at 25°C
CH4 fluxes on days 1 and 13, indicating that CH4 uptake increased in association with rotational grazing
Rotational grazed soils exhibited enhanced microclimate buffering (adaptive mechanism sustain microbial activity at low temperature. ): better structure, moisture retention, and organic matter foster stable microbial communities that remain active across temperature ranges.
In short: Rotational grazing doesn’t just avoid harm—it actively builds soil function, creating micro-environments where methanotrophs thrive.
Biodiversity Link:
According to the United Nations, biodiversity the main foundation for climate resilience, ecosystems with rich biodiversity, like those in well-managed pastoral lands, are more robust and adaptable in a changing climate.
New Zealand's farms, host 24% of the nation's native biodiversity on farmlands, more or less, adjacent to our protected conservation land this create ecological corridors that support soil health, microbial activity, including methane consumption—co-benefits affirmed by the UN’s recognition that land and ocean absorb more than half of all carbon emissions” through biodiverse ecosystems (UN Climate Issues: Biodiversity).
These aren’t just ecological side effects—they are deliberate outcomes of a farming philosophy that works with nature, not against it. And yet, under current climate accounting, this methane-consuming service remains invisible
A Larger Carbon Sink:
Likely a Larger Methane Sink:
New Research Reveals NZ's Land is a Larger Carbon Sink than Previously Thought:
A recent peer-reviewed study using inverse modelling, led by researchers from the University of Waikato, GNS Science, Manaaki Whenua – Landcare Research, and international institutions, has found that New Zealand's land acts as a significantly larger carbon dioxide (CO₂) sink than official estimates suggest. The paper, titled "Inverse modelling of New Zealand's carbon dioxide balance estimates a larger than expected carbon sink", 2025, was published in EGUsphere and reported by NIWA.
The research highlights that native forests and some pasturelands, long thought to be carbon neutral, are absorbing around 30% (and up to 60% in earlier reports) more CO₂ than previously accounted for by official New Zealand Greenhouse Gas Inventory and bottom-up ecosystem models.
1 Tg is equal to 1 Mt(Tg) Teragram ::: (Mt) Megatonne :::Offical Statistics are often in Mt
Study Key Findings:
Estimates New Zealand's terrestrial biosphere absorbed an average of:
–171 Tg CO₂ (± 29) per year between 2011 - 2020.
This is substantially larger than both;
–24 Tg CO₂ per year reported in New Zealand's official Greenhouse Gas Inventory (a seven-fold difference).
–118 ± 22 Tg CO₂ per year estimated by prior biosphere models (about 45% larger)..
This figure is seven times larger than official inventory estimates, suggesting:
New Zealand's land likely sequesters more carbon than its entire economy emits: currently ~80-90 Tg CO₂-e/year
Making New Zealand a net carbon sink
NZ sinks 81-90 Tg CO₂-e/year
Implications for Carbon Accounting and Beyond:
The study reveals a systematic flaw in New Zealand's climate accounting: an over-reliance on inventory-based bottom-up inventory models that fail to integrate real world data and consistently underestimate climate-regulating potential of low-disturbance ecosystems like native forests and well-managed pastoral lands.
Its findings have not yet been incorporated into official emissions reporting
Connecting to Methane Dynamics:
While the study focuses on CO₂ – NOT methane consumption by soil bacteria; its findings have profound implication for methane. If models New Zealand use miss carbon sinks, they almost certainly miss methane sinks too. Although CO₂ and CH₄ cycles are distinct, both are influenced by soil health, biodiversity and minimal disturbance.
Discovery of Methylocapsa gorgona:
High-Affinity Methanotroph’s :
2019 marked a major advance in understanding the biological methane sink, the discovery of Methylocapsa gorgona, this high-affinity methanotroph (HAM) can oxidise methane at trace atmospheric concentrations, a capability rare among methane-oxidising bacteria. Studies revealed M. gorgona can utilise atmospheric methane efficiently as a carbon and energy source, assimilate CO₂ fix nitrogen, and even harvest energy from trace gases such as carbon monoxide and hydrogen, enabling its survival in nutrient-poor environments.
Most importantly, Methylocapsa gorgona is abundant in common soils worldwide, including New Zealand. Both this methane consumers, commonality and efficiency imply its substantial role in global soil methane sinks.
The Arctic, once thought to be a net greenhouse gas emitter, has been reassessed following the discovery of high affinity methanotrophs (HAMs) in its upland soils – About 80% of the Arctic-boreal region. These soils consistently act as methane sinks by consuming atmospheric methane The overall Arctic region has spatially and temporally varying methane fluxes—some sinks and some sources,
Discovery of the Arctic's novel methanotroph populations may explain why observed methane emissions have averaged 5 - 10 gigatons less per year than climate models predicted.
NOAA Earth System Research Laboratory model simulation incorporating HAM and permafrost dynamics reduced Arctic net methane emissions and extends to global scaling, estimate soil sink up around 90 Tg CH4 yr, if HAMs dominate all upland soils suggesting that soil methane sinks may still significantly underestimated at three times the current accepted estimate by the IPCC.
Well managed soil for methane sink enhancement:
The discovery of Methylocapsa gorgona substantiates the argument that well-managed soils, particularly with robust methanotrophic habitats, play a foundational role in atmospheric methane regulation. Methanotrophic communities contribute far more to methane removal than previously acknowledged, emphasising the critical role of soil microbial biodiversity, native forests and land management in global greenhouse gas mitigation. This underpins calls for improved soil microbial ecology assessments in greenhouse gas inventories and climate mitigation policies globally, and specifically emphasises New Zealand’s unique opportunity to leverage soil biodiversity for methane sink enhancement.
In the New Zealand context, the presence of M. gorgona and similar high-affinity methanotrophs within healthy, biodiversity-rich soils—including those on pastoral lands adjacent to native forests and conservation areas—supports a powerful soil methane sink. The synergistic effects of ecological connectivity, soil health, and microbial biodiversity likely amplify methane oxidation beyond coarse inventory assumptions. Rotational grazing and low-input land management practices that preserve or enhance soil microbial habitat are therefore critical for maximising this natural methane mitigation potential.
How New Zealand’s Farming Model is Undermined by Outdated Climate Accounting:
Models suggest soils sink anywhere between 15-51Tg, with outliers up to 100Tg. The paper, Physiology of atmospheric methane-oxidising bacteria. estimates currently Soil and Forests sink 100Tg of methane combined, newer NOAA modelling incorporating high affinity methanotrophs, in uplands– like South Island soils, predicts global soil methane sinks alone could be 90 Tg CH4 yr.
Even the IPCC 2021 Framework puts Global soil sinks at estimated 32 [18–47] Tg CH₄ per year.
Yet, New Zealand's methane reporting remains frozen in an outdated 2006 IPCC framework, counting only livestock emissions. Ignoring Aotearoa-New Zealand's land sink entirely, a landscape scale biological climate solution.
The Consequence is a Double Injustice
Scientific Injustice: Complex agro-ecological systems are reduced to mere emission sources, ignoring their role in regulating atmospheric chemistry through natural sinks.
Social Injustice: Farmers practicing low-input, biodiversity-rich pastoralism, that simultaneously sequester CO₂ and consume CH₄—are penalised by policy, while receiving no acknowledgement for ecosystem services they steward.
While livestock may emit methane, they are part of a complex ecosystem that are part of earths ancient natural climate balancing mechanism. Livestock help build the very soil and feed the microorganisms and biodiversity that sinks methane, in an ancient closed loop system. This net effect is ignored in policy.
Yet, without modernised accounting this free, nature-based climate service remains invisible
Why NZ’s Accounting is Flawed:
IPCC 2006 Blind Spots;
The IPCC 2006 Guidelines, still the basis for New Zealand's for greenhouse gas inventories inventories omit methane consumption by agricultural soils. This creates a critical blind spot:
❌ No Soil Methane Sinks: No Soil Methane Sinks: No accounting for methanotropic activity or habitats in soil and pastures, only counting emissions from livestock.
❌ Outdated Science: Reliance on outdated science that predates critical discoveries on high affinity soil methanotrophs and complex soil microbial dynamics. .
❌ 2019 Refinement Falls Short: Even updated guidelines lack methodology to credit agricultural (and conservation forest) methane uptake.
❌ Overlooking Biodiversity's Role in Climate Mitigation: Beyond methane sinks, New Zealand's pastoral farming contributes significantly to biodiversity, which is intrinsically linked to climate resilience. New Zealand farmland hosts around 24% of New Zealand's native biodiversity. This creates complex habitats and ecosystem, including species that promote soil health and large microbial populations, including methane consuming methanotrophs.
Consequences
New Zealand's outdated 2006 IPCC methane accounting has dire real-world consequences that are more than academic:
Inflated Methane Footprint:
This means New Zealand’s methane footprint and overall GHG Footprint is artificially inflated, portraying pastoral farming as irredeemably polluting when well-managed systems could actually be close to neutral or net sinks.
The result?
❌ Farmers face punitive policies (the "burp tax") for gross emissions, while their land’s methane-sinking services and careful stewardship go unrewarded.
❌ Taxpayer funds are redirected into offsets and mitigation strategies and away from important core services, all Kiwi’s rely on.
Missed Climate Leadership Opportunities:
New Zealand’s low-input pastoral model and conservation ethos could position the nation as a global leader in climate-positive agriculture.
By failing to credit this natural methane sink:
❌ Stifled Policy Innovation: Regulations penalise low-input pastoral farmers while favouring industrial "quick fixes," undermining decades of on farm conservation integration, land stewardship and low-tech innovations (such as rotational grazing) in low-input natural pastoral farming.
❌ Eroded Market Trust: International consumers, increasingly demand natural products and transparent, sustainable supply chains. In the EU, this includes mandatory GMO labelling, country of origin and Farm to Fork labelling: carbon footprint (GHG emissions), water use, land use intensity, pollution, and biodiversity impact. Despite New Zealand’s leadership in sustainability, it cannot demonstrate its methane sink and carbon sink benefit without accurate metrics.
❌ Ceded Global Influence: As the EU and US explore soil carbon crediting, NZ’s reliance on IPCC 2006 has silenced its voice in shaping equitable climate frameworks, missing an opportunity to lead in farming in harmony with nature.
Climate Policies that Force Farmers Away From Nature-Based Models
❌ Cultural bias and marginalisation: Government bodies systemic bias undervalue nature and pastoral farming, pushing outdated emission metrics above all else, chanting farmers need to do more. Farmers are pushed to abandon long cultural traditions, of low-input natural farming and on farm conservation to experimental biotech quick fixes over long term sustainability.
❌ Ignores the offsetting role of soil methane sink: creates a distorted picture: pastoral farming appears as a one-way source of emissions, even though the same landscapes simultaneously remove a meaningful percentage of that methane from the atmosphere.
❌ Misrepresenting its true climate footprint: New Zealand’s agricultural emissions are overstated, penalising farmers for practices that yield net climate benefits, including both soil sinks, biodiversity, nature and wildlife habitats. ironically driving farmers to a more industrialised model.
Path Forward
Tier 3, country-specific accounting that credits both CO₂ sequestration and CH₄ consumption in pastoral soils would go some way to mitigate NZ’s inflated footprint.
Based on Inverse Modelling, 2025, NZ Land sinks -171 Tg CO₂ per annum, this should be reflected in our GHG accounting, current GHG records Land Sink at -24 Tg CO₂
Recognise national and on-farm biodiversity: as essential climate infrastructure, building resilience.
Reward PURE NATURE Farming: low-input pastoral systems that maximise methanotroph habitats
Partner with Australia, Brazil, and the EU to demand IPCC methodology updates by 2026 that: Shift from viewing farms as emission sources to valuing them as dynamic climate-regulating ecosystems.
This paradigm shift stems from recognising New Zealand’s three unique strengths:
world-leading soils,
low-input pastoral farming traditions,
and biodiversity conservation.
This creates a landscape-scale biological climate solution.
New Zealand has a once-in-a-generation opportunity: to lead the world in climate-positive farming. New Zealand’s farms and livestock aren’t the problem—they’re managing a climate solution validated by atmospheric science. The bacteria are working overtime. Soils are pulling double duty. And native biodiversity is weaving a resilient ecological fabric.
It’s time our accounting did the same.
We challenge policymakers: Update GHG inventories to reflect 21st-century science and natural cycles, and the world most significant biological sink for atmospheric methane, soil.
Rewrite the Rules,
Reward the Stewards!
References
-
Inverse modelling of New Zealand's carbon dioxide balance estimates a larger than expected carbon sink, 2025 ::
NZ sinks 171 Tg carbon per annum (+/-29Tg)Global Methane Budget 2000–2020. 2025, Earth System Science Data.
Variation in methane uptake by grassland soils in the context of climate change– A review of effects and mechanisms. 2023
Global Uptake of Atmospheric Methane by Soil From 1900 to 2100, 2021
Adaptive Multi-Paddock Grazing Lowers Soil Greenhouse Gas Emission Potential by Altering Extracellular Enzyme Activity, 2020 ::
Methane soil sink 1.5 times greater in soils under rotational grazing.Agriculture's impact on microbial diversity, 2011
High Affinity Methanotrophs Are an Important Overlooked Methane Sink in Arctic and Global Methane Budget and Informing global methane budgets with soil methane oxidation models and atmospheric inversions, 2021,
NOAA modelling incorporating high affinity methanotrophs predicts global soil methane sinks as large as 90 Tg CH4 yr⁻¹Reduced net methane emissions due to microbial methane oxidation in a warmer Arctic, 2020
Widespread soil bacterium that oxidizes atmospheric methane, 2019
Physiology of atmospheric methane-oxidizing bacteria. Current Opinion in Biotechnology. 2025 ::
Combined soil and tree uptake up to 100 Tg CH4/yr.Meta-analysis shows the impacts of ecological restoration on greenhouse gas emissions (2024). Nature Communications.
Grassland restoration increases methane uptake by 31%, forests restoration by 90% Overall, forest, grassland and wetland restoration decrease the global warming potentials by 327.7%, 157.7% and 62.0% compared with their paired control ecosystems, respectively.Pristine New Zealand forest soil is a strong methane sink, 2004, Global Change Biology; Price, Sherlock, Kelliher, McSeveny
The first measurements for a pristine Southern Hemisphere forest are reported here. Soil CH4 oxidation rate averaged 10.5±0.6 kg CH4 ha−1 yr−1, with the greatest rates in dry warm soil (up to 17 kg CH4 ha/yr)… Methanotrophic activity was concentrated beneath the organic horizon at 50–100 mm depth … For New Zealand, national-scale extrapolation of our data suggested the potential to offset 13% of CH4 emissions from ca. 90 M ruminant animals. Our average was about 6.5 times higher than rates reported for most Northern Hemisphere forest soils.UN Biodiversity - our strongest natural defence against climate change
https://www.un.org/en/climatechange/science/climate-issues/biodiversityThermophilic methane oxidation is widespread in Aotearoa-New Zealand geothermal fields, 2023 Houghton, Karen M.; Carere, Carlo R.; Stott, Matthew B.; McDonald, Ian R.
Article: Harnessing Super-Methanotrophs, 2015, Summary of Research
https://pureadvantage.org/harnessing-super-methanotrophs/
-
For NOAA model with high affinity methanotrophs; see Arctic section
IPCC, Refinement to the 2006 IPCC Guidelines. 2019
Soil methane oxidation range 9–47 Tg CH4/yr; rising with warming.Global Methane Budget 2000–2020. 2025, Earth System Science Data.
Overview: Estimates soil methane uptake broadly at ~35 Tg CH4 per year globally, which corresponds to roughly 10% of total atmospheric methane removal. However, considering the chemical sink as >90%, soils represent the most significant biological sink. Some modelling estimates report sink ranges up to 51 Tg CH4/year, which implies soils can account for closer to ~20% of the biological methane sink.Variation in methane uptake by grassland soils in the context of climate change– A review of effects and mechanisms. 2023, Science of the Total Environment.
Grassland methane sink 20–40 Tg/yr, projected increase to 82.7 ±4.4 Tg/yr by 2100.
Natural and semi-natural grasslands are one of the most biodiverse ecosystems in the world, characterised by high species richness of plants and pollinators. They also provide shelter, feeding and breeding grounds for many different animals. In addition, grasslands provide many ecosystem services, such as water retention, flood prevention and protection against erosion, and act as a biological filter reducing environmental pollution.Consumption of atmospheric methane by soils: A process-based model
suggest that the global sink strength lies within the range 20–51 Tg yr−1 CH4, with a preferred value of 38 Tg yr−1 CH4.Global Uptake of Atmospheric Methane by Soil From 1900 to 2100, 2021,
used the process-based methanotrophy model Methanotrophy Model (MeMo) v1.0 and output from global climate models to simulate regional and global changes in soil uptake of atmospheric CH4 from 1900 to 2100. The annual global uptake doubled from 17.1 ± 2.4 Tg to 37.2 ± 3.3 Tg yr−1 from 1900-2015 and could increase further to 82.7 ± 4.4 Tg yr−1 by 2100 (RCP8.5), primarily due to enhanced diffusion of CH4 into soilMethane Production in Soil Environments—Anaerobic Biogeochemistry. 2020, Angel R., Conrad R.
Modelled soil uptake ~33.5 Tg CH4/yr currently; projected 24- 89 Tg CH4/yr by 2100.Methane and Global Environmental Change. 2018 Annual Review of Environment and Resources (.Cicerone R.J., Oremland R.S.).
Soil sinks 9–47 Tg CH4/yr; strongest in natural forests and grasslands.Soil Methanotrophy Model (MeMo v1.0): a process-based model to quantify global uptake of atmospheric methane by soil, 2018, Murguia-Flores F.
33.5 ± 0.6 Tg CH4/yrMethane Feedbacks to the Global Climate System in a Warmer World. 2017, Reviews of Geophysics.
Soil sink range 28–47 Tg CH4/yr; increase expected with warming.Three decades of global methane sources and sinks, 2013. Earth System Science Data.
Soil sink range 20–51 Tg CH4/yr.Characterisation of Methanotrophic Bacterial Populations in Soils Showing Atmospheric Methane Uptake. 2009, Applied and Environmental Microbiology.
Soil sink 20–60 Tg CH4/yr; Notes, sensitive to land-use.Atmospheric methane consumption in arid ecosystems. 2009. ISME Journal,
Soil sink 30–42 Tg CH4/yr; arid/semiarid pastures significant methane sinks.Methane oxidation in upland soils: An exact solution to the diffusion-reaction equation. Biogeochemistry. 2007
Estimates the global soil methane sink with a broad range of 9 to 47 Tg CH4/year depending on model parameterisation, suggesting soil sinks can account for a significant portion (approaching 20%) of atmospheric methane consumptionProduction, oxidation, emission and consumption of methane by soils: A review. 2001, Le Mer and Roger, European Journal of Soil Biology
Temperate and tropical oxic soils estimated to consume 10% atmospheric methane, Upland soils estimated to consume about 6% of atmospheric methane; however, incorporating ranges and uncertainties, the contribution is likely higher in global methane budgets (potentially 20% of the biological sink). Methods: Comprehensive review and synthesis of field measurements, chamber flux studies, and modellingSoils as sources and sinks for atmospheric methane. Canadian Journal of Soil Science. 1997, Topp, E., and Pattey, E.
Aerobic soils including pasture and forest soils contribute an estimated 20-30 Tg CH4/year, which forms a major sink component. Methane oxidation rates can vary with land use but soils play an important methane sink role estimated as up to 20% of the atmospheric methane sink under optimal conditions. Methods: Field flux measurements, laboratory incubation studies, and microbial population analyses. Soils as sources and sinks for atmospheric methane. Pastoral soils contribute significantly, ~30 Tg CH4/yr.
-
Adaptive Multi-Paddock Grazing Lowers Soil Greenhouse Gas Emission Potential by Altering Extracellular Enzyme Activity, 2020,
Variation in methane uptake by grassland soils in the context of climate change– A review of effects and mechanisms. 2023, Science of the Total Environment
Physiology of atmospheric methane-oxidizing bacteria. Current Opinion in Biotechnology. 2025.
Combined soil and tree uptake up to 100 Tg CH4/yr.Biological and physical controls of methane uptake in grassland soils across the US Great Plains, 2024. Koyama, Johnson, Brewer, Webb, & Von Fischer, Ecosphere
Methane uptake rates in US Great Plains grasslands peak at intermediate soil moisture levels, with net methanotroph activity more important than gas diffusivity for temporal variations. Uptake rates observed are around 3 to 5 kg CH4 ha⁻¹ yr⁻¹ across sites.Resilience of aerobic methanotrophs in soils; spotlight on the methane sink under agriculture, 2024
Natural grassland conversion to agriculture [cropping] or pine plantations: Effects on soil methane uptake, 2024, All land uses studied acted as net CH4 sinks. Land-use change from grassland to agriculture [cropping] decreased soil CH4 uptake (~37% ± 19), whereas afforestation increased (~85% ± 73) this environmental service related to natural grassland… Organic matter is an important driver .. | .. study suggesting there is no need for a high tree cover to increase the CH4 sink of the soil.
Meta-analysis shows the impacts of ecological restoration on greenhouse gas emissions (2024). Nature Communications.
Grassland restoration increases methane uptake by 31%, forests restoration by 90% Overall, forest, grassland and wetland restoration decrease the global warming potentials by 327.7%, 157.7% and 62.0% compared with their paired control ecosystems, respectively.Resilience of aerobic methanotrophs in soils. 2023, FEMS Microbiology Ecology.
Agriculture maintains ~30 Tg CH4/yr soil methane uptake.Methane oxidation affected by grassland type and grazing. 2022, Science of the Total Environment
Grazing influences methane uptake; ‘set stock’ lowered sink vs ‘free grazing’ increased sink (description of free grazing, similar → rotational grazing)Elevated and atmospheric-level methane consumption by soil methanotrophs of three grasslands in China. 2023, Global Change Biology.
Agriculture's impact on microbial diversity. 2011, Soil Science Society of America Journal. Levine, Teal, Robertson, Schmidt
Well-managed agriculture enhances soil methane sinks.…
METHANE Sources, Sinks and Uncertainties, 2021, Peter Bruce-Iri, Max Purnell, Walter Jehne, Thorsten Arnold, Alfred Harris
Biodiversity: The forgotten 60%: Bird ecology and management in New Zealand’s agricultural landscapes. Published in the New Zealand Journal of Ecology, 2008
-
High Affinity Methanotrophs Are an Important Overlooked Methane Sink in Arctic and Global Methane Budget and Informing global methane budgets with soil methane oxidation models and atmospheric inversions, 2021, AGU Fall Meeting Abstracts.
NOAA modelling incorporating high affinity methanotrophs predicts global soil methane sinks as large as 90 Tg CH4 yr⁻¹, up to three times previous estimates and significantly correcting Arctic and global methane budget models.
https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/924135
https://gml.noaa.gov/publications/annual_meetings/2019/slides/4-Oh.pdf
https://gml.noaa.gov/publications/annual_meetings/2019/abstracts/27-190329-C.pdfReduced net methane emissions due to microbial methane oxidation in a warmer Arctic, 2020
Methane emissions from organic-rich soils in the Arctic have been extensively studied due to their potential to increase the atmospheric methane burden as permafrost thaws. However, this methane source might have been overestimated without considering high-affinity methanotrophs (HAMs; methane-oxidizing bacteria) recently identified in Arctic mineral soils. Herein we find that integrating the dynamics of HAMs and methanogens into a biogeochemistry model that includes permafrost soil organic carbon dynamics leads to the upland methane sink doubling (~5.5 Tg CH4 yr−1) north of 50 °N in simulations from 2000–2016.Article: Methane-Eating Bacteria Could Help Decrease Greenhouse Gas Emissions From Thawing Arctic Tundra, 2020
Methane-eating microbes, ARCTIC CLIMATE FEEDBACKS 2020, ..model shows potential increased methane produced from thawing permafrost carbon could be offset by increased consumption by upland methanotrophs.
One Step Closer to Enigmatic USCα Methanotrophs: Isolation of a Methylocapsa-like Bacterium from a Subarctic Soil, 2023
Methanotrophy across a natural permafrost thaw environment, 2018, Geoscientific Model Development, 11, 2009–2026. DOI: 10.5194
Methanogens at the top of the world: occurrence and potential activity of methanogens in newly deglaciated soils in high-altitude cold deserts in the Western Himalayas, 2013
-
Physiology of atmospheric methane-oxidizing bacteria, 2025 Tveit
Physiological basis for atmospheric methane oxidation and methanotrophic growth on air, 2024 Tveit
Simultaneous Oxidation of Atmospheric Methane, Carbon Monoxide and Hydrogen for Bacterial Growth, 2021 Tveit
Novel methanotrophic and methanogenic bacterial communities from diverse ecosystems and their impact on environment, 2021
A number of conventional methanotrophic and methanogenic communities are reported from marine and coastal environment, forest/desert ecosystem, paddy field soil, fresh water lakes, swamps and other soil ecosystemsWidespread soil bacterium that oxidizes atmospheric methane. Proceedings of the National Academy of Sciences USA. 2019
Article: A VIGOROUS DEVOURER OF GREENHOUSE GAS IS LIVING BENEATH OUR FEET, 2019
-
Pristine New Zealand forest soil is a strong methane sink, 2004, Global Change Biology; Price, Sherlock, Kelliher, McSeveny
The first measurements for a pristine Southern Hemisphere forest are reported here. Soil CH4 oxidation rate averaged 10.5±0.6 kg CH4 ha−1 yr−1, with the greatest rates in dry warm soil (up to 17 kg CH4 ha/yr)… Methanotrophic activity was concentrated beneath the organic horizon at 50–100 mm depth … For New Zealand, national-scale extrapolation of our data suggested the potential to offset 13% of CH4 emissions from ca. 90 M ruminant animals. Our average was about 6.5 times higher than rates reported for most Northern Hemisphere forest soils.Physiology of atmospheric methane-oxidizing bacteria. Current Opinion in Biotechnology. 2025.
Combined soil and tree uptake up to 100 Tg CH4/yr.Atmospheric methane consumption in arid ecosystems acts as a reverse chimney and is accelerated by plant-methanotroph biomes, 2025
atmospheric methane consumption ranged between 2.26 and 12.73 μmol m2 h−1, peaking during the daytime at vegetated sitesEnhanced plant diversity reduces nitrous oxide emissions in forest soils worldwide, 2025
Species diversity in forests reduces Nitrous oxide emissionsMeta-analysis shows the impacts of ecological restoration on greenhouse gas emissions (2024). Nature Communications.
Grassland restoration increases methane uptake by 31%, forests restoration by 90% Overall, forest, grassland and wetland restoration decrease the global warming potentials by 327.7%, 157.7% and 62.0% compared with their paired control ecosystems, respectively.Global atmospheric methane uptake by upland tree woody surfaces. 2024, Nature Communications, Tree sinks
24.6–49.9 Tg CH4/yr complements soils sinks 24.6–49.9 Tg CH4/yr for total sink ~100 Tg CH4/yr.How tree traits modulate tree methane fluxes: A review, 2024,
Global estimates of forest soil methane flux identify a temperate and tropical forest methane sink 2023
Global estimates of forest soil methane flux identify a temperate and tropical forest methane sink 2023
Example of typical > forests as partial source of methane, moderate sink.
Nearly 3.17% of the total area of global forest soils was a net CH4 source.
The global mean CH4 uptake in forest soils was 3.95 kg CH4 ha−1 yr−1.Pristine New Zealand forest soil is a strong methane sink, 2004, Global Change Biology; Price, Sherlock, Kelliher, McSeveny
-
Thermophilic methane oxidation is widespread in Aotearoa-New Zealand geothermal fields, 2023 Houghton, Karen M.; Carere, Carlo R.; Stott, Matthew B.; McDonald, Ian R.
Methylacidimicrobium thermophilum AP8, a Novel Methane- and Hydrogen-Oxidizing Bacterium Isolated From Volcanic Soil on Pantelleria Island, Italy, 2021
Article: Harnessing Super-Methanotrophs, 2015
https://pureadvantage.org/harnessing-super-methanotrophs/Varying atmospheric methane concentrations affect soil methane oxidation rates and methanotroph populations in pasture, an adjacent pine forest, and a landfill, 2012