Global Methane Budget 2000–2020

Опубликована: Июнь 6, 2024

Abstract. Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. Emissions atmospheric concentrations of CH4 continue increase, maintaining as second most human-influenced greenhouse gas in terms forcing after carbon dioxide (CO2). The relative importance compared CO2 temperature change related its shorter lifetime, stronger radiative effect, acceleration growth rate over past decade, causes which are still debated. Two major challenges reducing uncertainties factors explaining well-observed arise from diverse, geographically overlapping sources uncertain magnitude temporal destruction by short-lived highly variable hydroxyl radicals (OH). To address these challenges, we have established a consortium multi-disciplinary scientists under umbrella Global Carbon Project improve, synthesise update regularly stimulate new research on cycle. Following Saunois et al. (2016, 2020), present here third version living review paper dedicated decadal budget, integrating results top-down emission estimates (based in-situ observing satellite (GOSAT) observations an ensemble inverse-model results) bottom-up process-based models estimating land-surface emissions chemistry, inventories anthropogenic emissions, data-driven extrapolations). We recent 2010–2019 calendar decade (the latest period full datasets available), previous 2000–2009 year 2020. revision this edition benefits progress inland freshwater with better accounting lakes ponds, reservoirs, streams rivers. This also reduces double across wetland and, first time, includes estimate potential that exists (average 23 Tg yr-1). Bottom-up approaches show combined average 248 [159–369] yr-1 decade. Natural fluxes perturbed human activities through climate, eutrophication, land use. In estimate, component contributing emissions. Newly available gridded products allowed us derive almost complete latitudinal regional based approaches. For estimated inversions (top-down) be 575 (range 553–586, corresponding minimum maximum model ensemble). Of amount, 369 or ~65 % attributed direct fossil, agriculture waste biomass burning 350–391 63–68 %). period, give slightly lower total than 2010–2019, 32 9–40). Since 2012, trends been tracking scenarios assume no minimal mitigation policies proposed Intergovernmental Panel Climate Change (shared socio-economic SSP5 SSP3). methods suggest 16 (94 yr-1) larger (669 yr-1, range 512–849) inversion period. discrepancy between budgets has greatly reduced differences (167 156 respectively), time uncertainty overlap. distribution inversion-based indicates predominance tropical southern hemisphere (~65 <30° N) mid (30° N–60° N, ~30 emissions) high-northern latitudes (60° N–90° ~4 emissions). similar though contributions latitudes, smaller tropics inversions. Although bottom-up, source attributable natural especially those wetlands freshwaters. identify five priorities improving budget: i) producing global, high-resolution map water-saturated soils inundated areas emitting robust classification different types ecosystems; ii) further development inland-water emissions; iii) intensification at local (e.g., FLUXNET-CH4 measurements, urban-scale monitoring, imagery pointing capabilities) scales (surface networks remote sensing measurements satellites) constrain both inversions; iv) improvements transport representation photochemical sinks inversions, v) integration 3D variational systems using isotopic and/or co-emitted species such ethane well information super-emitters detected (mainly oil sector but coal, landfills) improve partitioning. data presented can downloaded https://doi.org/10.18160/GKQ9-2RHT (Martinez al., 2024).

Язык: Английский

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Practical Guide to Measuring Wetland Carbon Pools and Fluxes

Wetlands, Год журнала: 2023, Номер 43(8)

Опубликована: Ноя. 28, 2023

Abstract Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, dioxide and methane emissions, aquatic C fluxes. However, underlying biogeochemical processes that affect wetland pools fluxes are complex dynamic, making measurements challenging. Over decades research, many observational, experimental, analytical approaches been developed to understand quantify C. Sampling range in their representation from short long timeframes local landscape spatial scales. This review summarizes common cutting-edge methodological for quantifying We first define each major provide rationale importance dynamics. For approach, we clarify what component is measured its temporal representativeness constraints. describe practical considerations such as where when an approach typically used, who can conduct (expertise, training requirements), how conducted, including equipment complexity costs. Finally, key covariates ancillary enhance interpretation findings facilitate model development. The protocols measure soil, water, vegetation, gases also relevant related disciplines ecology. Improved quality consistency data collection reporting across studies will help reduce uncertainties develop management strategies use wetlands nature-based climate solutions.

Язык: Английский

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Upscaling Wetland Methane Emissions From the FLUXNET‐CH4 Eddy Covariance Network (UpCH4 v1.0): Model Development, Network Assessment, and Budget Comparison

AGU Advances, Год журнала: 2023, Номер 4(5)

Опубликована: Сен. 6, 2023

Abstract Wetlands are responsible for 20%–31% of global methane (CH 4 ) emissions and account a large source uncertainty in the CH budget. Data‐driven upscaling fluxes from eddy covariance measurements can provide new independent bottom‐up estimates wetland emissions. Here, we develop six‐predictor random forest model (UpCH4), trained on 119 site‐years flux data 43 freshwater sites FLUXNET‐CH4 Community Product. Network patterns site‐level annual means mean seasonal cycles were reproduced accurately tundra, boreal, temperate regions (Nash‐Sutcliffe Efficiency ∼0.52–0.63 0.53). UpCH4 estimated 146 ± TgCH y −1 2001–2018 which agrees closely with current land surface models (102–181 overlaps top‐down atmospheric inversion (155–200 ). However, diverged both types spatial pattern dynamics tropical We conclude that has potential to produce realistic extra‐tropical will improve more data. To reduce upscaled estimates, researchers could prioritize along humid‐to‐arid climate gradients, major rainforest basins (Congo, Amazon, SE Asia), into monsoon (Bangladesh India) savannah (African Sahel) be paired improved knowledge extent these regions. The monthly products gridded at 0.25° available via ORNL DAAC ( https://doi.org/10.3334/ORNLDAAC/2253

Язык: Английский

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Ensemble estimates of global wetland methane emissions over 2000–2020

Biogeosciences, Год журнала: 2025, Номер 22(1), С. 305 - 321

Опубликована: Янв. 15, 2025

Abstract. Due to ongoing climate change, methane (CH4) emissions from vegetated wetlands are projected increase during the 21st century, challenging mitigation efforts aimed at limiting global warming. However, despite reports of rising emission trends, a comprehensive evaluation and attribution recent changes remains limited. Here we assessed wetland CH4 2000–2020 based on an ensemble 16 process-based models. Our results estimated average 158 ± 24 (mean 1σ) Tg yr−1 over total annual area 8.0 2.0×106 km2 for period 2010–2020, with 6–7 in 2010–2019 compared 2000–2009. The increases four latitudinal bands 90–30° S, 30° S–30° N, 30–60° 60–90° N were 0.1–0.2, 3.6–3.7, 1.8–2.4, 0.6–0.8 yr−1, respectively, 2 decades. modeled sensitivities temperature show reasonable consistency eddy-covariance-based measurements 34 sites. Rising was primary driver increase, while precipitation atmospheric CO2 concentrations played secondary roles high levels uncertainty. These suggest that change is driving increased direct sustained needed monitor developments.

Язык: Английский

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Variable rate precision application of feedlot cattle manure mitigates soil greenhouse gas emissions

Geoderma, Год журнала: 2025, Номер 454, С. 117172 - 117172

Опубликована: Янв. 22, 2025

Язык: Английский

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Drivers of Soil Carbon Variability in North America’s Prairie Pothole Wetlands: A Review

Wetlands, Год журнала: 2025, Номер 45(1)

Опубликована: Янв. 1, 2025

Язык: Английский

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Exploring environmental and meteorological factors influencing greenhouse gas emissions on major urbanized cities in Bangladesh

Urban Climate, Год журнала: 2025, Номер 60, С. 102369 - 102369

Опубликована: Март 1, 2025

Язык: Английский

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Non‐Floodplain Wetlands Are Carbon‐Storage Powerhouses Across the United States

Earth s Future, Год журнала: 2025, Номер 13(4)

Опубликована: Апрель 1, 2025

Abstract Understanding wetland carbon stores and dynamics are critical to managing global flux. Non‐floodplain wetlands (NFWs) hydrologically dynamic globally prevalent inland distal fluvial flowpaths, lacustrine‐fringing areas, geomorphic floodplains; >50% the world's remaining have been reported as NFWs. Quantifying NFW represents a substantive carbon‐budget gap. We analyze conterminous‐US (CONUS) field‐based data collected from nearly 2000 sites sampled by National Wetlands Condition Assessment (NWCA) representing ∼38 Mha CONUS wetlands, asking: What is mean soil organic density total storage in different hydrogeomorphically classified types? To what extent does NFWs differ other How vary between altered intact NFWs? find that relative types, carbon‐storing powerhouses, containing approximately 1.5x per ha than types sampled. CONUS‐wide, store more across every depth increment: ∼2.0x types. Further, condition affects dynamics: least impaired had 1.6x found intermediately disturbed 1.8x of most‐disturbed These NWCA data, plus waning societal protections, suggests releases destruction landscapes likely increase—perhaps markedly—in coming years (e.g., through hydrology affecting atmospheric release NFW‐stored well dissolved export).

Язык: Английский

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Recent increases in annual, seasonal, and extreme methane fluxes driven by changes in climate and vegetation in boreal and temperate wetland ecosystems

Global Change Biology, Год журнала: 2024, Номер 30(1)

Опубликована: Янв. 1, 2024

Abstract Climate warming is expected to increase global methane (CH 4 ) emissions from wetland ecosystems. Although in situ eddy covariance (EC) measurements at ecosystem scales can potentially detect CH flux changes, most EC systems have only a few years of data collected, so temporal trends remain uncertain. Here, we use established drivers hindcast changes fluxes (FCH since the early 1980s. We trained machine learning (ML) model on 22 [methane‐producing sites] wetland, upland, and lake sites FLUXNET‐CH database with least two full across temperate boreal biomes. The gradient boosting decision tree ML then hindcasted daily FCH over 1981–2018 using meteorological reanalysis data. found that, mainly driven by rising temperature, half ( n = 11) showed significant increases annual, seasonal, extreme , ca. 10% or higher fall 1981–1989 2010–2018. annual were during summer fall, particularly high‐CH ‐emitting fen dominated aerenchymatous plants. also that distribution days extremely high (defined according 95th percentile values reference period) become more frequent last four decades currently account for 10–40% total seasonal fluxes. share was greatest winter boreal/taiga spring sites, which highlights increasing importance non‐growing seasons budgets. Our results shed light effects climate wetlands, appears be extending emission emissions.

Язык: Английский

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Factors Regulating the Potential for Freshwater Mineral Soil Wetlands to Function as Natural Climate Solutions

Wetlands, Год журнала: 2025, Номер 45(1)

Опубликована: Янв. 1, 2025

There are increasing global efforts and initiatives aiming to tackle climate change mitigate its impacts via natural solutions (NCS). Wetlands have been considered effective NCS given their capacity sequester retain atmospheric carbon dioxide (CO

Язык: Английский

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