Reviews & Analysis

Ecosystems on land take up roughly a quarter of the carbon emitted through fossil fuel use, but a global analysis of carbon flux measurements indicates that the increase in photosynthetic uptake by drylands is slowing, thereby limiting their potential to mitigate climate change.

Grounding-line motion of the Antarctic Ice Sheet is driven by climate variability, challenging the assumption that the bed slope at the grounding line alone controls their behaviour, according to a synthesis of glaciological and climate research.

Radar swath imagery has been used to identify subglacially sourced debris in dozens of structures within the Greenland Ice Sheet. Some debris-rich horizons (termed ‘debris trains’) extend more than 1,000 m off the ice sheet bed. Debris trains are likely to form during terrestrial ice sheet readvance, when the warm core of a relict ice sheet interacts with its new, thin, frozen margin.

Subduction transfers redox budgets from the surface into the mantle. Quantitative modelling of a Mariana-type subduction system shows that mantle oxidation is dominated by sulfur-rich fluids and Fe³⁺-rich melts at sub-arc and back-arc depths, respectively. Most of the redox budget is ultimately transported into the deep mantle with the subducting slab.

Soil moisture drives critical land–atmosphere interactions and compound hazards. Closing gaps in data and models is key to integrating soil moisture into predictive frameworks for improved hazard forecasting.

Shifts in large-scale climate patterns are reshaping flood risk worldwide. Advances in modelling now offer the potential to provide early warnings and develop effective tools for managing rising coastal hazards.

We revealed that carbon dioxide emissions from the Congo Basin’s largest humic lakes partially originate from millennia-old peat. This discovery identifies a pathway whereby deep, long-sequestered carbon is respired and mobilized by subsurface flows, indicating these massive reservoirs of organic carbon are less inert than previously assumed.

Microplastics impact terrestrial soil carbon dynamics, altering carbon storage, according to a synthesis of studies of microplastics and soil carbon cycling.

Top-down inversion modelling, coupled with data from ten observing stations across China, reveals that the country’s emissions of hydrofluorocarbons (HFCs) grew during the period 2011–2021. However, over a similar period, non-Annex 1 countries (mostly developing countries under the UN climate framework), excluding China, are shown to be the largest contributors to the global growth in HFC emissions.

Long-term field experiments demonstrate that elevated CO₂ and warming synergistically constrain phosphorus availability to plants by promoting its retention in iron–organic matter complexes and microbial biomass, thereby intensifying nutrient limitations that might threaten rice yields under future climate conditions.

Our study demonstrated that zonal asymmetry is a fundamental and persistent characteristic of Antarctic Circumpolar Current (ACC) strength over orbital timescales. This asymmetric behaviour reshapes our understanding of how the ACC interacts with Antarctic Ice Sheet dynamics, modulates global ocean circulation and influences the carbon cycle across past and future climate states.

Erosion by the West Antarctic Ice Sheet can supply iron to the Southern Ocean, with iron solubility as important as iron quantity in shaping ocean productivity and carbon cycling. The future projection of ocean carbon dynamics will therefore require integration of ice-sheet processes into ocean biogeochemistry models.

Projections using a machine-learning model, trained on historical socioeconomic and water-resources data, reveal the impact of inequality on water security and predict that, by 2100, 63% of the global population could face severe water scarcity. Pathways of societal development driven by technological efficiency could result in even greater inequality and water insecurity.

Global drifter data reveal that tropical cyclone-induced sea surface cooling in storm-affected areas is far weaker than indicated by estimates from microwave satellites and state-of-the-art climate models. Despite enhanced self-induced cooling driven by greenhouse warming, tropical cyclones are fuelled by a sea surface warming trend that is about twice the tropical mean warming.

The use of groundwater can help mitigate the impacts of natural disasters, thereby increasing the resilience of communities during and after events, according to a synthesis of hydrology and disaster response research.

Post-fire soil erosion is a widespread global phenomenon with geomorphological consequences. Quantifying its impacts provides insights to inform and strengthen soil conservation efforts.

Heat-producing elements like uranium and thorium are depleted in the lower crust. The geochemistry of crustal rocks suggests ultrahigh melting temperatures are needed to produce this depletion and may also help stabilize the crust.

Our oceans are changing rapidly, with climate-driven shifts in circulation and nutrient cycles reshaping marine ecosystems in profound ways. One of the most visible and disruptive outcomes is the explosive growth of Sargassum — a floating brown alga that has, since 2011, formed vast rafts stretching thousands of kilometres across the Atlantic Ocean.

The oxygenation of Earth’s atmosphere ~2.45–2.30 billion years ago may have initiated in the oxidized bottom waters of marine shelves, according to a synthesis of thallium and nitrogen isotopes and cyanobacteria phylogenetic records.