Extensive fire-driven degradation in 2024 marks worst Amazon forest disturbance in over 2 decades Biogeosciences DOI 10.5194/bg-22-5247-2025 7 October 2025 The Amazon forest faces increasing wildfires due to extreme drought and human activity. In 2024, disturbances surged by 152 %, hitting a 20-year high. Forest degradation from fires grew by over 400 %, exceeding that from deforestation. Brazil and Bolivia were hit hardest. These fires released huge amounts of CO2, 7 times more than in recent years, pushing the Amazon towards a dangerous tipping point. Urgent action is needed to prevent irreversible harm. Read more
Increased future ocean heat uptake constrained by Antarctic sea ice extent Earth System Dynamics DOI 10.5194/esd-16-1453-2025 3 October 2025 Future projections of global ocean heat uptake (OHU) strongly differ between climate models. Here, we reveal an observational constraint on future OHU based on historical Antarctic sea ice extent observations. This emergent constraint is based on a coupling between sea ice, deep- and surface ocean temperatures, and cloud feedback. It implies an upward correction of 2024–2100 global OHU projections by up to 14 % and suggests that previous constraints have underestimated future warming. Read more
The coupled oxygen and carbon dynamics in the subsurface waters of the Gulf and Lower St. Lawrence Estuary and implications for artificial oxygenation Ocean Science DOI 10.5194/os-21-2179-2025 2 October 2025 We combine two decades of oxygen data with new carbon observations and a tracer-informed model to quantify oxygen loss and carbon buildup in the deep waters of the Gulf and Lower St. Lawrence Estuary. We then test a novel idea: reoxygenating these waters with the oxygen produced as a by-product from green-hydrogen production. Our results suggest this could significantly reduce hypoxia, though full recovery would require larger inputs. Read more
Insights from hailstorm track analysis in European climate change simulations Natural Hazards and Earth System Sciences DOI 10.5194/nhess-25-3693-2025 1 October 2025 Hailstorms can cause severe damage to homes, crops, and infrastructure. Using high-resolution climate simulations, we tracked thousands of hailstorms across Europe to study future changes. Large hail will become more frequent, hail-covered areas will expand, and instances of extreme hail combined with heavy rain will double. These shifts could increase risks for communities and businesses, highlighting the need for better preparedness and adaptation. Read more
Visualising historical changes in air pollution with the Air Quality Stripes Geoscience Communication DOI 10.5194/gc-8-229-2025 1 October 2025 The Air Quality Stripes images visualise historical changes in particulate matter air pollution in over 150 cities worldwide. The project celebrates significant improvements in air quality in regions like Europe, North America, and China while highlighting the urgent need for action in areas such as central Asia. Designed to raise awareness, the images aim to inspire discussions about the critical impact of air pollution and the global inequalities it causes. Read more
Food trade disruption after global catastrophes Earth System Dynamics DOI 10.5194/esd-16-1585-2025 30 September 2025 The global food trade system can handle small disturbances, but large disasters could cause major disruptions. We looked at how nuclear war or severe infrastructure loss would affect global trade in key crops. Both would be catastrophic, but a nuclear war would cause more severe disruptions, with many countries losing most of their food imports. Both scenarios highlight the need for better preparation to protect global food security. Read more
Physiological responses to ultra-high CO2 levels in an evergreen tree species Biogeosciences DOI 10.5194/bg-22-5069-2025 28 September 2025 As atmospheric CO2 increases globally, plants increase the rate of photosynthesis. Still, leaf–gas exchange can be downregulated by the plant. Here we tested the limits of these plant responses in a fruit tree species under very high CO2 levels relevant to the future Earth and to contemporary Mars. Plant water use decreased at 1600 ppm CO2 and remained low at 6000 ppm. Photosynthesis significantly increased at 6000 ppm. In summary, ultra-high CO2 may partly compensate for limited water availability. Read more
Technical note: Pondi – a low-cost logger for long-term monitoring of methane, carbon dioxide, and nitrous oxide in aquatic and terrestrial systems Biogeosciences DOI 10.5194/bg-22-5051-2025 27 September 2025 The Pondi is a cost-effective, lightweight logger designed for long-term monitoring of carbon dioxide, methane, and nitrous oxide emissions in both terrestrial and aquatic ecosystems. It addresses key challenges in greenhouse gas monitoring by providing an automated, low-cost, solar-powered solution with cloud connectivity and real-time analytics. Its robust design enables deployment in diverse environmental conditions, supporting large-scale, high-resolution emission assessments. Read more
Learning predictable and informative dynamical drivers of extreme precipitation using variational autoencoders Weather and Climate Dynamics DOI 10.5194/wcd-6-995-2025 26 September 2025 Large-scale atmospheric dynamics modulate the occurrence of extreme events and can improve their prediction. We present a generative machine learning method to identify key dynamical drivers of an impact variable in the form of targeted circulation regimes. Applied to extreme precipitation in Morocco, we show that these targeted regimes are more predictive of the impact while preserving their own predictability and physical consistency. Read more
4D GPR imaging of a near-terminus glacier collapse feature The Cryosphere DOI 10.5194/tc-19-4045-2025 25 September 2025 We demonstrate the use of a drone-based ground-penetrating radar (GPR) system to gather high-resolution, high-density 4D data over a near-terminus glacier collapse feature. We monitor the growth of an air cavity and the evolution of the subglacial drainage system, providing insights into the dynamics of the collapse event. This work highlights potential future applications of drone-based GPR for monitoring glaciers, in particular in regions which are inaccessible by surface-based methods. Read more
Impacts of eutrophication and deoxygenation on the sediment biogeochemistry in the Sea of Marmara Biogeosciences DOI 10.5194/bg-22-4953-2025 24 September 2025 This study aims to understand the impacts of deoxygenation and eutrophication on sedimentary biogeochemical processes in the Sea of Marmara. We showed that diffusive phosphorus and fixed nitrogen fluxes were markedly high under highly eutrophic and hypoxic areas of the Sea of Marmara. This benthic feedback may exacerbate the ongoing eutrophication and deoxygenation in the Sea of Marmara, which is now at risk of becoming one of the major marine dead zones. Read more
Multidecadal trends in CO2 evasion and aquatic metabolism in a large temperate river Biogeosciences DOI 10.5194/bg-22-4923-2025 23 September 2025 To understand the role of rivers in the global carbon cycle, this 32-year study tracked carbon dioxide in France's Loire River. We found emissions decreased over the long term, despite varying more than tenfold from year to year. While the river ecosystem shifted from algae to plant dominance, this decrease in emissions was primarily driven by reduced groundwater inputs. This shows that catchment-scale hydrology can be more important than in-river biology for a river's carbon footprint. Read more
The Arctic Weather Satellite radiometer Atmospheric Measurement Techniques DOI 10.5194/amt-18-4709-2025 22 September 2025 The Arctic Weather Satellite (AWS), developed by the European Space Agency, highlights a new approach in satellite design, aiming to expand the network of operational microwave sensors cost-effectively. Launched in August 2024, AWS features a 19-channel microwave cross-track radiometer. Notably, it introduces groundbreaking channels at 325.15 GHz. In addition, AWS acts as the stepping stone to a suggested constellation of satellites, denoted as EUMETSAT Polar System Sterna. Read more
Assessment of source regions of the Zambezi River: implications for regional water security Hydrology and Earth System Sciences DOI 10.5194/hess-29-4557-2025 21 September 2025 This study focused on the sources of the Zambezi River, revealing new insights into its longest tributary and Angola's key role in its flow. River expeditions and earth observation data show that Angola contributed approximately 73 % of the river's flow upstream of a major floodplain during the 2023 late wet season. We highlight Angola's wetlands, which support river health and help mitigate pollution. These findings stress the need for improved monitoring and regional cooperation in the basin. Read more
Peatland development reconstruction and complex biological responses to permafrost thawing in Western Siberia Biogeosciences DOI 10.5194/bg-22-4797-2025 20 September 2025 Western Siberian peatlands regulate global climate, but their response to permafrost thaw remains poorly studied. Our study analyzed peat cores from a peat plateau and a lake edge to track changes over two centuries. We found that permafrost thawing, driven by rising temperatures, altered peatland hydrology, vegetation, and microbial life. These shifts may expand with further warming, affecting carbon storage and climate feedbacks. Our findings highlight early warning signs of ecosystem change. Read more
The historical representation and near-future (2050) projections of the Coral Sea current system in CMIP6 HighResMIP Ocean Science DOI 10.5194/os-21-2001-2025 17 September 2025 We examined projected changes in Coral Sea temperature and currents through to 2050 using high-resolution CMIP6 models. Surface warming deepened by 30 m per decade, reaching 400 m by 2050. There was sub-surface cooling between 400 and 600 m. North Vanuatu Jet and North Caledonian Jet transports weakened, and the South Caledonian Jet strengthened. These changes may influence western boundary currents and upwelling dynamics on the Great Barrier Reef. Read more
The 1538 eruption at the Campi Flegrei resurgent caldera: implications for future unrest and eruptive scenarios Natural Hazards and Earth System Sciences DOI 10.5194/nhess-25-3421-2025 16 September 2025 We compare recent unrest episodes at the Campi Flegrei caldera (Naples, Italy) with phenomena that occurred during the historical eruption in 1538. Besides proposing a new, accurate reconstruction of the ground movements in the area since the 8th century BCE, we deduce a striking similarity of the present unrest with the precursors to the 1538 eruption. We then infer that, if the ground uplift continues, earthquakes of up to magnitude 5 are expected, as well as a considerable eruption risk in the next few decades. Read more
Drift-aware sea ice thickness maps from satellite remote sensing The Cryosphere DOI 10.5194/tc-19-3785-2025 16 September 2025 We developed a new method to map Arctic sea ice thickness daily using satellite measurements. We address a problem similar to motion blur in photography. Traditional methods collect satellite data over 1 month to get a full picture of Arctic sea ice thickness. But in the same way as in photos of moving objects, long exposure leads to motion blur, making it difficult to identify certain features in the sea ice maps. Our method corrects for this motion blur, providing a sharper view of the evolving sea ice. Read more
ESD Ideas: Climate tipping is not instantaneous – the duration of an overshoot matters Earth System Dynamics DOI 10.5194/esd-16-1523-2025 15 September 2025 Climate tipping points are not committed upon crossing critical thresholds in global warming, as is often assumed. Instead, it is possible to temporarily overshoot a threshold without causing tipping, provided the duration of the overshoot is short. In this Idea, we demonstrate that restricting the time over 1.5 °C would considerably reduce tipping point risks. Read more
Linking crystallographic orientation and ice stream dynamics: evidence from the EastGRIP ice core The Cryosphere DOI 10.5194/tc-19-3805-2025 15 September 2025 A better understanding of ice flow requires more observational data. The EastGRIP core is the first ice core through an active ice stream. We discuss crystal orientation data determining the present deformation regimes. A comparison with other deep cores shows the unique properties of EastGRIP and shows that deep ice likely originates from the Eemian. We further show that the overall plug flow of NEGIS is characterised by many small-scale variations, which remain to be considered in ice flow models. Read more
