Reviews & Analysis

A new study tracks sea ice, ocean swell and ice shelf conditions over multiple years in the lead-ups to large-scale Antarctic ice shelf calving events. We quantified the strengths and durations of increased ice shelf flexure that preconditioned and subsequently triggered the calving events.

New experiments shed light on the complex interplay between rock deformation and metamorphism. Slab stagnation in Earth’s mantle transition zone may be explained by transient weakening during the olivine–spinel phase transition.

Calculation of the sulfur and water budgets released from magma during the 2022 eruption of Hunga volcano — the largest submarine eruption recorded — shows that of 18.8 Tg of sulfur dioxide released, <7% entered the atmosphere. The remaining sulfur dioxide dissolved in the ocean during explosive magma fragmentation at 400–1,000 m below sea level.

The Indian summer monsoon plays a key part in influencing marine life in the Bay of Bengal. Palaeoceanographic records reveal that both extremely weak and strong monsoon phases led to declines in marine productivity. Future monsoon shifts pose a disruptive threat to the stability of regional ecosystems and fisheries.

Atmospheric oxygen, supplied from the oceans, dramatically rose during the Great Oxidation Event. Our examination of the preceding evolution of seawater oxygenation revealed that the redox state in seawater oscillated between oxic and anoxic conditions before oceanic oxygenation again increased towards the dawn of the Great Oxidation Event.

Measurements from a robotic underwater vehicle reveal the impacts of meltwater from the giant iceberg A-68A on the properties of the surrounding Southern Ocean. In addition to increasing surface stratification and mid-depth vertical mixing, the meltwater impacts primary productivity, with direct and indirect effects on ecosystems and carbon cycling.

Aquatic vegetation has an important role in lake methane emissions. Between 1984 and 2021 the maximum area of aquatic vegetation in northern lakes (>40° N) expanded by 2.3 × 10⁴ km². This expansion could substantially increase long-term total methane emissions from lakes.

Analysis of global datasets indicates that dry to wet transitions in soil wetness over regions spanning around 500 km can increase the size and rainfall intensity of organized thunderstorms around the world. Therefore, observations of soil moisture could improve storm forecasts and support adaptation to changing hazards under climate change.

High-pressure experiments reveal that calcium solubility in bridgmanite is insufficient to fully remove davemaoite from the Earth’s lower mantle. We propose that davemaoite-enriched domains form at the core–mantle boundary, serving as reservoirs for incompatible elements and offering a potential explanation for large low shear-wave velocity provinces.

Ongoing climate change might alter the Atlantic–European jet and affect hydroclimate extremes. Reconstructions of jet metrics for 1421–2023 show that summer drought in Central Europe coincided with a poleward shift and flood episodes coincided with an equatorward shift. Recent changes (past 30 years) are still within the boundaries of past variability.

Natural gradients across surface ocean regions show that changes in carbonate chemistry projected for ocean alkalinity enhancement could promote the proliferation of calcifying phytoplankton. This shift would increase an alkalinity sink, thus reducing the efficiency of ocean alkalinity enhancement as a CO₂ removal method.

The rigid-body motion of Earth’s wandering inner core has now been reliably tracked over the past 20 years. With this knowledge, we can compare seismic recordings obtained when the inner core returns to the same position after moving for several years. More is changing than just the inner core position; the soft outermost inner core probably deforms.

Near-daily sampling of volcanic ash during a three-month eruption reveals shifts in mantle-derived liquid magma (melt) composition, highlighting its potential as a monitoring and forecasting tool. These shifts align with the amplitude of volcanic tremor, a persistent seismic signal, suggesting a link between magma viscosity, shallow bubble escape dynamics, and tremor changes.

This study examines the influence of agricultural irrigation on heat stress and contrasts it against local impacts of urbanization in North American cities using regional climate model simulations. The results indicate that irrigation decreases air temperature and increases relative humidity, with daytime urban moist heat stress reduced according to most indices.

Atmospheric CO₂ enrichment inhibits the growth and activity of autotrophic nitrifiers through aggravation of anoxic stress in a nitrogen-rich paddy soil, according to a long-term free-air CO₂ enrichment experiment. This CO₂-induced inhibition effect on nitrifiers might contribute to the decline of inorganic nitrogen pools in lowland soil systems.

Field measurements and computer simulations show how fishing methods that drag weighted nets along the seabed counteract the seafloor sediments’ role as a carbon sink. The effect is ambiguous in weakly trawled areas but becomes clear in intensely trawled grounds.

By incorporating remote sensing and modelling evidence, we show that China’s growing biomass carbon stock over the past two decades has been dominated by the expansion and conservation of woody areas. Approximately half of the biomass carbon sinks were attributed to direct management effects with substantial contributions from national ecological restoration projects.

Laboratory experiments show that Fe(II) oxidizing phototrophic bacteria, or photoferrotrophs, thought to be a major depositor of Archean and Palaeoproterozoic iron formations, are inhibited by toxic intermediates produced during denitrification in iron-rich systems. This identifies a previously overlooked stressor impacting mineral formation by photoferrotrophs during early Earth history.

Modelling of the evolution of the Kosi drainage basin near Chomolungma suggests that a river capture event occurred approximately 89 ka ago. Isostatic rebound due to this capture event could contribute 10–50% of the total rock uplift rate in the Chomolungma region and might partly explain Chomolungma’s renewed uplift rate and anomalous elevation.

A re-evaluation of global land-to-ocean carbon exports using a multi-model ensemble and a database of observations reveals that the export of carbon by rivers is 20% higher than that reported in the 2021 Intergovernmental Panel on Climate Change (IPCC) assessment. These findings underscore the important contribution of riverine carbon to the carbon budget.