Wildfires offset the increasing but spatially heterogeneous Arctic–boreal CO2 uptake

Nature Climate Change, Journal Year: 2025, Volume and Issue: 15(2), P. 188 - 195

Published: Jan. 21, 2025

Abstract The Arctic–Boreal Zone is rapidly warming, impacting its large soil carbon stocks. Here we use a new compilation of terrestrial ecosystem CO 2 fluxes, geospatial datasets and random forest models to show that although the was overall an increasing sink from 2001 2020 (mean ± standard deviation in net exchange, −548 140 Tg C yr −1 ; trend, −14 P < 0.001), more than 30% region source. Tundra regions may have already started function on average as sources, demonstrating shift dynamics. When fire emissions are factored in, no longer statistically significant (budget, −319 −9 ), permafrost becomes neutral −24 123 −3 underscoring importance this region.

Language: Английский

---

The net ecosystem carbon balance (NECB) at catchment scales in the Arctic

Frontiers in Environmental Science, Journal Year: 2025, Volume and Issue: 13

Published: April 7, 2025

The Net Ecosystem Carbon Balance (NECB) is a crucial metric for understanding integrated carbon dynamics in Arctic and boreal regions, which are vital to the global cycle. These areas associated with significant uncertainties rapid climate change, potentially leading unpredictable alterations dynamics. This mini-review examines key components of NECB, including sequestration, methane emissions, lateral transport, herbivore interactions, disturbances, while integrating insights from recent permafrost region greenhouse gas budget syntheses. We emphasize need holistic approach quantify incorporating all their uncertainties. review highlights methodological advances flux measurements, improvements eddy covariance automatic chamber techniques, as well progress modeling approaches data assimilation. Key research priorities identified, such improving representation inland waters process-based models, expanding monitoring networks, enhancing integration long-term field observations approaches. efforts essential accurately quantifying current future budgets rapidly changing northern landscapes, ultimately informing more effective change mitigation strategies ecosystem management practices. aligns goals Monitoring Assessment Program (AMAP) Conservation Flora Fauna (CAFF), providing important policymakers, researchers, stakeholders working understand protect these sensitive ecosystems.

Language: Английский

---

Impacts of Permafrost Degradation on N₂O Emissions From Natural Terrestrial Ecosystems in Northern High Latitudes: A Process‐Based Biogeochemistry Model Analysis

Global Biogeochemical Cycles, Journal Year: 2025, Volume and Issue: 39(4)

Published: April 1, 2025

Abstract Nitrous oxide (N 2 O) is a potent greenhouse gas with its radiative forcing 265–298 times stronger than that of carbon dioxide (CO ). Recent field studies show N O emissions from northern high latitude (north 45°N) ecosystems have increased due to warming. However, spatiotemporal quantification remains inadequate in this region. Here we revise the Terrestrial Ecosystem Model incorporate more detailed processes soil nitrogen (N) biogeochemical cycling, permafrost thawing effects, and atmospheric deposition. then used analyze natural terrestrial Our study reveals regional production net 1969 2019. Production rose 1.12 (0.82–1.46) 1.18 (0.84–1.51) Tg yr −1 , while 0.98 (0.7–1.34) 1.05 (0.72–1.39) considering thawing. Emissions regions grew 0.37 (0.2–0.57) 0.41 (0.21–0.6) . Soil uptake atmosphere remained relatively stable at 0.12 (0.1–0.15) Atmospheric deposition significantly emission by 37.2 ± 2.9%. Spatially, act as sources or sinks −12 900 mg m −2 depending on changing temperature, precipitation, characteristics, vegetation types. findings underscore critical need for observational reduce uncertainty budget.

Language: Английский

---

Permafrost and Freshwater Systems in the Arctic as Tipping Elements of the Climate System

Surveys in Geophysics, Journal Year: 2025, Volume and Issue: unknown

Published: May 2, 2025

Language: Английский

---

Global Methane Budget 2000–2020

Earth system science data, Journal Year: 2025, Volume and Issue: 17(5), P. 1873 - 1958

Published: May 9, 2025

Abstract. Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. CH4 second most human-influenced greenhouse gas in terms of forcing after carbon dioxide (CO2), both emissions atmospheric concentrations have continued increase since 2007 a temporary pause. The relative importance compared those CO2 temperature change related its shorter lifetime, stronger radiative effect, acceleration growth rate over past decade, causes which are still debated. Two major challenges factors responsible observed arise from diverse, geographically overlapping sources uncertain magnitude temporal destruction by short-lived highly variable hydroxyl radicals (OH). To address these challenges, we established consortium multidisciplinary 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 situ Greenhouse Gases Observing SATellite (GOSAT) observations an ensemble inverse-model results) bottom-up process-based models estimating land surface chemistry, inventories anthropogenic emissions, data-driven extrapolations). We recent 2010–2019 calendar decade (the latest period full data sets available), previous 2000–2009 year 2020. revision this 2025 edition benefits progress inland freshwater with better counting lakes ponds, reservoirs, streams rivers. This also reduces double across wetland and, first time, includes estimate potential that may exist (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, 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). 2020 highest reaches 608 581–627), 12 higher 2000s. 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 2020) respectively), time uncertainties overlap. Although bottom-up, source uncertainty attributable natural especially wetlands freshwaters. tropospheric loss methane, as main contributor at 563 [510–663] chemistry–climate models. These values due impact rise remaining large (∼ 25 sink 633 [507–796] 554 [550–567] However, use same OH distribution, introduces less likely justified. agriculture contributed 228 [213–242] 211 [195–231] budget. Fossil fuel 115 [100–124] 120 [117–125] Biomass biofuel 27 [26–27] 28 [21–39] 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 local (e.g. FLUXNET-CH4 measurements, urban-scale monitoring, satellite imagery pointing capabilities) scales (surface networks remote sensing measurements satellites) constrain inversions; (iv) improvements transport representation photochemical sinks (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. presented can downloaded https://doi.org/10.18160/GKQ9-2RHT (Martinez al., 2024).

Language: Английский

---

Permafrost in the climate system: Feedbacks, cycles, future trends, ecological and social implications

Elsevier eBooks, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

Language: Английский

---