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Extreme weather reshapes how soils store and release carbon

11 September 2026 at 11:17

Beneath every step we take, soils hold one of the planet’s largest reservoirs of carbon, a vast, slow-moving bank of organic matter that quietly regulates how much of the world’s carbon stays locked away and how much escapes into the atmosphere as greenhouse gas. Now a sweeping new review warns that climate-driven extremes, droughts, floods, and wildfires, are rewriting the rules of that subterranean economy in ways that conventional models and land-management practices have not yet caught up with. The analysis, led by environmental scientist Nanthi Bolan of the University of Western Australia and colleagues, including a corresponding authorship by Bolan himself, synthesizes a substantial body of global evidence on how extreme weather reshapes carbon inputs to soil, microbial processing, erosion, and the sequestration of carbon that underpins soil health, water retention, nutrient cycling, and agricultural productivity.

The work, published in the journal Carbon Research, is notable for the scale of its underlying evidence base. On 14 January 2026, the authors searched Google Scholar, PubMed, and Web of Science using terms spanning climate change, extreme weather, soil carbon, microbial activity, decomposition, erosion, dissolved organic matter, and leaching. The initial sweep returned 14,218 records; after removing duplicates and screening for eligibility, 3,754 articles remained for bibliometric and qualitative analysis. From those, 187 publications were selected for detailed synthesis based on relevance, methodological rigor, and the substantive quality of their findings. Keyword co-occurrence patterns were mapped with VOSviewer, a bibliometric tool that reveals the intellectual architecture of a research field. The result is a critical review grounded in structured literature screening rather than new experimental data, but its synthesis offers one of the most comprehensive maps yet of how extremes rearrange the soil carbon cycle.

The review’s central finding is that no two extremes act alike. Drought, the most widespread disturbance, operates largely through the plant side of the equation. When rainfall fails, photosynthesis slows, plant biomass production falls, and the total flux of carbon entering soils through roots, residues, and litter declines. There is a nuance here: under moderate water stress, plants may temporarily shift a greater proportion of their fixed carbon belowground, investing in roots to chase moisture. But prolonged drought overwhelms that compensatory response. Microbial biomass shrinks, litter decomposition stalls, and the living engine of the soil carbon cycle idles. Then comes the deceptive twist: when rain finally returns, rewetting triggers a rapid pulse of carbon dioxide as starved soil microbes seize upon the accumulated substrates left behind by months of suspended activity. That post-drought CO₂ flush, the review emphasizes, can erase much of the apparent “savings” that accumulated during the dry period. Across the assembled evidence, repeated and multi-year drought was consistently associated with declining soil organic carbon, with grasslands and arable croplands showing particularly pronounced losses, ecosystems that happen to anchor much of the world’s food production.

Flooding tells the opposite story, but it ends in many of the same places. Water saturation chokes off oxygen diffusion through soil pores, forcing microbial metabolism into anaerobic pathways. That shift changes everything downstream. Prolonged waterlogging can drive the chemical reduction of iron oxyhydroxides, minerals that in oxygenated conditions act as microscopic glues binding organic carbon to soil particles. When those minerals dissolve, the carbon they held is released as dissolved organic carbon, which can then be stripped away by erosion and leaching and exported to rivers, lakes, and ultimately the ocean. The review stresses, however, that flooding is not unambiguously a carbon loss story. Wetlands and other periodically inundated ecosystems can accumulate and retain enormous carbon stocks precisely because water constrains decomposition. Whether a flood event releases carbon or banks it depends on the interplay between plant inputs, oxygen availability, and hydrological transport, a delicate balance that shifting rainfall regimes are actively destabilizing.

Wildfire is the most dramatic and immediately visible of the three forces, and its effects cascade on multiple timescales. Combustion directly strips vegetation, litter, and soil organic matter, transferring carbon to the atmosphere in hours. But fire also rearranges the physical and biological landscape of the soil in subtler ways: it can increase erosion by removing protective ground cover, alter soil wettability in ways that change hydrological behavior, restructure microbial communities, and expose previously protected carbon, once shielded inside aggregates or mineral associations, to fresh decomposition. There is a paradoxical bright spot. Pyrogenic carbon, the charcoal-like residue of incomplete combustion, is chemically recalcitrant and can persist in soils for centuries or millennia, functioning as a long-term carbon sink. Whether a fire leaves a landscape as a net carbon source or stabilizes some of its carbon in pyrogenic form depends on fire severity, soil moisture, fuel load, ecosystem type, and the trajectory of post-fire recovery. The review is clear that this balance cannot be predicted from fire alone; it is contingent, site by site, on conditions that vary widely across the globe.

Perhaps the most consequential theme running through the synthesis is that carbon responses cannot be inferred from the type of extreme event alone. Land use, soil mineralogy, hydrology, salinity, vegetation composition, microbial community makeup, and the timing of events within a season all determine whether carbon ends up stored, mobilized, or released. Iron and aluminum oxyhydroxides and clay minerals, for instance, provide mineral protection that can shield organic matter even under stress, while sandy or low-clay soils offer little such refuge. Managed croplands respond differently from native grasslands; saline coastal soils behave differently from acidic forest soils. And compound events, drought followed by wildfire, or alternating drought and flooding in rapid succession, may produce effects that are qualitatively different from those of isolated disturbances, as when a dried landscape burns more intensely, or when post-fire soils, stripped of vegetation, wash away in the first heavy rain. The review argues that the climate science and soil science communities have largely studied these disturbances one at a time, while the real world increasingly delivers them in combination.

The implications for climate mitigation and adaptation are substantial. Soil organic carbon is frequently invoked in national climate pledges and voluntary carbon markets as a bankable sink, yet the review suggests that the security of that bank depends heavily on how often and how severely extremes strike. If multi-year droughts steadily drain carbon from grasslands and croplands, or if fires repeatedly reset accumulation cycles, the effective permanence of soil carbon storage becomes far more fragile than many accounting frameworks assume. Conversely, protecting and rebuilding soil carbon delivers benefits well beyond climate: it improves water retention in drought-prone regions, supports nutrient cycling, stabilizes soil structure against erosion, and sustains the microbial diversity on which fertility depends. Carbon stewardship, in other words, is not separable from food security or ecosystem resilience; it is the same problem viewed from different angles.

The authors are candid about the limits of the current evidence base. The article does not report newly generated datasets and does not present a dedicated limitations section, and its conclusions rest on a qualitative synthesis of selected publications. Consequently, they call for improved and more consistent evidence across soil types, land uses, and both terrestrial and aquatic environments, and across multiple temporal scales, from the instantaneous CO₂ pulse after rewetting to the multi-decadal trajectory of carbon storage. Standardizing measurements of carbon pools, microbial functions, and event intensity, they argue, would make results comparable across ecosystems and enable more confident generalization, something the field currently struggles to achieve given heterogeneous methods and site-specific reporting.

Looking forward, the review sketches a research agenda that is as technologically ambitious as it is mechanistically focused. The authors recommend integrating high-resolution remote sensing with ground observations, advanced spectroscopy, molecular analyses, and integrated modeling to track carbon as it moves through soils and into waterways. They single out several priorities: characterizing microbial genomic and functional diversity as it responds to stress, quantifying carbon stoichiometry, probing the interactions between organic matter and iron and aluminum oxyhydroxides, understanding clay-mineral protection mechanisms, tracking long-term storage outcomes, and systematically studying the sequencing of compound extreme events. Each of these threads addresses a gap in the mechanistic chain that links a weather event in the atmosphere to a molecule of carbon, stabilized or released, in the soil.

What emerges from the review is a picture of the soil carbon cycle not as a stable background process but as a dynamic, contested system whose behavior under climate extremes is far less predictable than once assumed. The same storm that floods a rice paddy and exports carbon to a river delta may, a few hundred kilometers away, end a drought and briefly green a grassland, with opposite consequences for the atmosphere. As extremes grow more frequent and more compound, the review makes the case that understanding, and safeguarding, the carbon held beneath our feet will require science that is as interconnected and as restless as the weather itself.

Keywords

soil organic carbon, extreme weather, drought, flooding, wildfire, carbon sequestration, microbial activity, dissolved organic carbon, erosion, pyrogenic carbon, climate change, soil health

Subject of Research: Impacts of climate change-induced extreme weather events (drought, flooding, wildfire) on carbon dynamics in soil

Article Title: Impacts of climate change-induced extreme weather events on carbon dynamics in soil

Article References: Bolan, N., Messiga, A. J., Sharma, S., Mukherjee, S., Bolan, S., Salehin, S. M. U., Rupngam, T., Rajan, N., Zhang, T., Yang, Y., Jagadesh, M., & Siddique, K. H. M. (2026). Impacts of climate change-induced extreme weather events on carbon dynamics in soil. Carbon Research, 5(1), Article 58. https://doi.org/10.1007/s44246-026-00300-5

Image Credits: AI Generated

DOI: 10.1007/s44246-026-00300-5

Keywords: adaptation of land management practices to climate extremes, challenges to conventional soil carbon models, Climate change impacts on soil carbon storage, effects of droughts and floods on soil microbial activity, global evidence on soil carbon dynamics, implications for greenhouse gas emissions, influence of extreme weather on nutrient cycling and water retention, resilience of soil carbon reservoirs to climate, review of climate-driven soil carbon processes, soil erosion and carbon loss due to extreme weather, soil health and agricultural productivity under climate stress, wildfire influence on soil organic matter

Proxima Fusion bets €140M on a critical fusion ingredient dominated by Asian suppliers

10 September 2026 at 19:38
Proxima Fusion said Wednesday it plans to build a €140 million ($162.6 million) factory to produce fusion-grade high-temperature superconducting (HTS) tape, which will provide the startup with key component to its reactor design.

How far ahead can we predict the weather?

10 September 2026 at 13:00

What will the weather be like tomorrow, or next week or, indeed, in a month’s time? Today’s numerical weather predictions can easily answer the first two parts of this question, but they fall short beyond about 14 days. New work on predictability limits by scientists at the University of Miami and the NOAA Cooperative Institute for Marine and Atmospheric Studies (CIMAS) say that this maximum could be extended to around 129 days – but probably no further. Whether this limit can be reached in practice, however, will depend on future improvements in forecasting technologies, they say.

Numerical weather prediction was developed in the late 1940s. Indeed, it was one of the first major applications of electronic computers. As these have advanced, so have the predictions. Indeed, thanks to ever more sophisticated mathematical models capable of analysing increasing amounts of observational data, we can now predict, for example, when hurricanes will occur as far as eight days in advance – something that was deemed impossible even a few decades ago. But how far ahead can such predictions be made?

Previous attempts to determine this predictability limit have largely relied on analysing the behaviour of very small perturbations in the atmosphere. These tiny errors, however, are inaccessible either observationally or via numerical modelling, explains Zoltan Toth of the NOAA who led this new study together with his colleague Wei Zhang. “These past studies therefore had to make some assumptions about the behaviour of the small errors, and these assumptions are necessarily somewhat arbitrary.”

Analysing the energetic balance of the atmosphere

The method developed by Toth, Zhang and their colleagues makes no reference to this error behaviour and instead goes back to analysing the energetic balance of the atmosphere, which continually absorbs solar radiation on the molecular level. In their approach, the researchers began by considering how our planet’s atmosphere would behave as a closed system, the deterministic dynamics of which preserves information about its initial state, assumed to be perfectly known. In theory, such a hypothesis would allow forecasts of the atmosphere’s behaviour right out to infinity. This is not possible in reality, they explain, because the atmosphere is obviously not a closed system: it receives and emits radiation. In the real atmosphere, the phases of photons in sunlight are completely random and cannot be determined, injecting quantum-scale uncertainty into the atmosphere.

These unknown quantum characteristics act as noise and destroy any retained information, beginning first of all on the smallest scales, explain the researchers. As these scales become bigger, noise eventually affects all parts of the system. When the total energy in the atmosphere is entirely replaced, the ability to make any prediction is completely lost.

“Using the relatively well-measured quantities of total energy in the atmosphere and the incoming and outgoing solar radiation fluxes at its upper boundary, we estimate that the range of skilful forecasts could potentially be extended from 14 days as at present to 129 (±7) days at the most,” explains Toth.

Very different from the mainstream discourse

“This result is very different from the mainstream discourse about atmospheric predictability, which to this day is strongly influenced by early publications in the field,” adds Toth. “More recently even, the authors of a 2018 article in the Bulletin of the American Meteorological Society speculated on whether current forecast systems are reaching their limits for when it comes to predicting tropical cyclones. In 2020, we argued that this limit is at least decades, if not much farther away.”

The theoretical foundation for the new methodology to determine the time limit of predictability is rather simple, he says. “At its core is a conceptual realization, which came to us intuitively. This is that the energy turnover time (that is, the time it takes for all energy in the atmosphere to be replaced by incoming solar radiation) is equivalent to the upper limit of predictability.”

While there is no complex mathematics involved, Toth notes that he and his colleagues had to find a way to describe the technique in a readily understandable way – something that was not easy, he admits, given the complexity of the subject.

Looking ahead, the researchers, who detail their present work in Advances in Atmospheric Sciences, are now looking into several other independent ways to estimate the limit of predictability. “There is no doubt, this limit has a theoretical feel to it,” Toth tells Physics World. “Yet there are a number of very practical implications for both traditional equation- and AI-based modelling of the atmosphere following on from the theory of predictability that we are also exploring in a series of ongoing studies.”

The post How far ahead can we predict the weather? appeared first on Physics World.

Farmed salmon may not be as nutritious as it once was, new research suggests

Eat more fatty fish.

That dietary advice has changed the way the world consumes salmon, pushing consumer demand ever upward and production to higher and higher levels. Most of that demand is being met with farmed salmon: Today, nearly 70 percent of the salmon consumed on the planet are raised in pens and cages.

The US Department of Agriculture’s Dietary Guidelines for Americans recommend eating at least 8 ounces of fish a week and urges people to choose salmon or other species that are similarly high in “heart-healthy” Omega-3 fatty acids. But new research led by USDA scientists finds that levels of these fatty acids in farmed salmon have dropped considerably, potentially making the agency’s own advice, and similar recommendations, including from the American Heart Association, outdated and insufficient.

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NASA’s PREFIRE Satellites Show How the Poles Trade Heat With Space

11 August 2026 at 05:00

At Earth’s poles, much of the heat leaving the planet is invisible to human eyes. NASA’s two PREFIRE CubeSats are measuring that far-infrared energy directly, and a new animation built from two complete seasonal cycles shows just how differently the Arctic and Antarctic warm and cool. The Polar Radiant Energy in the Far-InfraRed Experiment began […]

The post NASA’s PREFIRE Satellites Show How the Poles Trade Heat With Space appeared first on Curiosmos.

Sila lands $1.4B Pentagon loan as militaries demand more batteries

10 August 2026 at 16:22
Battery materials startup Sila will use a $1.4 billion loan from the U.S. Department of Defense to scale production at its factory in Washington state.

The long-term fate of Earth’s biosphere

10 August 2026 at 12:00

The economist John Maynard Keynes once remarked, “In the long run we are all dead.” From an astronomical standpoint, this is true for the Earth itself. In roughly 5 billion years, the Sun will exhaust the hydrogen at its core and enter the next phase of its life as a Red Giant, where it will swell up large enough to engulf and destroy the Earth.

Currently, the Sun is still in its main-sequence phase, where it fuses hydrogen into helium in its core. Although it remains relatively stable during this phase, it will gradually grow brighter with time. As the Sun shines brighter, the increased heat and radiation will raise Earth’s surface temperature, potentially pushing it past the threshold for life to survive. 

One of Earth’s geological processes that helps regulate its surface temperature is the carbon cycle. Over millions of years, carbon moves from the Earth’s interior into the atmosphere as carbon dioxide or CO2, where it functions as a greenhouse gas that traps heat. Plants take in this CO2 through photosynthesis and move carbon through the biosphere. 

Meanwhile, rain and rock weathering draw carbon into the oceans and rocks. By pulling CO2 out of the atmosphere, the carbon cycle could mitigate Earth’s warming as the Sun brightens over time. Today, human activities are increasing atmospheric CO2 and warming the planet. However, over billions of years, the carbon cycle could gradually remove enough CO2 from the atmosphere that eventually too little would remain to support photosynthesis. 

With these challenges to life on Earth in mind, the researchers Jacob Haqq‐Misra and Eric Wolf investigated how long Earth’s biosphere could last in the distant future. The team used computer models to calculate the balance of energy that Earth would receive and emit over time, accounting for the effects of increasing sunlight and changing atmospheric CO2 concentrations. They followed this up with calculations using the ExoCAM model to determine the temperature and atmospheric conditions of future Earth across different latitudes. They related these conditions to a habitability metric to determine their impact on the biosphere.

To estimate the biosphere’s maximum possible lifespan, the team conducted 29 simulations representing the planet’s conditions over the next 2 billion years. In one set of simulations, the Earth’s carbon cycle contributed little to regulating surface temperature, with the atmosphere’s CO2 concentration fixed at approximately modern levels of 400 parts per million (ppm) and surface temperatures continuing to increase. In another, the carbon cycle worked to keep Earth’s average surface temperature fixed at the modern average of approximately 59℉ (15℃), no matter how much it had to reduce CO2 in the atmosphere. 

In the scenario with a fixed CO2 concentration, the team found that in 1.7 billion years, Earth’s surface reached an average of 122°F (50°C), which is too hot for most land plants. After 1.9 billion years, it reached 149°F (65°), becoming too hot for all land plants to survive as temperatures continued to rise. 

They also found that in the fixed average surface temperature scenario, atmospheric CO2 dropped below the 150 ppm level that most plants require for photosynthesis within 500 million years. After 1.4 billion years, CO2 levels fell below 10 ppm, leaving only a few land photosynthesizers and aquatic plants alive. After about 1.8 billion years, atmospheric CO2 dropped to 1 ppm, leaving only microbes capable of photosynthesis.

The researchers’ findings generally extend the estimated lifetime of Earth’s future biosphere compared with earlier, simpler models that suggested maximum lifespans of 100 million to 1.5 billion years. However, they clarified that other scientists should verify their results by running tests with other models, especially under extreme conditions of high incoming solar radiation and low atmospheric CO2. 

Lastly, Haqq‐Misra and Wolf noted that their model did not account for major evolutionary changes that could help life adapt to future conditions. Over time, plants could evolve to tolerate higher temperatures or lower atmospheric CO2 levels. Future humans or another intelligent species might also engage in large-scale geoengineering projects to prevent the end of life on Earth. If life on Earth proves adaptable enough, the biosphere may endure until a Red Giant fills the daytime sky.

The post The long-term fate of Earth’s biosphere appeared first on Sciworthy.

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