Research Briefing

In a part of the Apennines, where the Earth’s crust is thin and heat flow is high, production of CO₂ from deep below the mountains dominates over near-surface weathering processes that consume this greenhouse gas. Ultimately, the magnitude of deep CO₂ release tips the balance towards a landscape that is a net carbon emitter.

Aerosol–cloud interactions are the largest uncertainty in radiative forcing. We combined machine learning and long-term satellite observations to quantify aerosol fingerprints on tropical marine clouds, using degassing volcanic events in Hawaii as natural experiences, and found that cloud cover increased relatively by 50% in humid and stable atmosphere, leading to strong cooling radiative forcing.

There are no good models for the chemical evolution of the Earth’s surface over the planet’s lifetime, because models typically overlook the progressive build-up of carbonate rocks in the crust. A new model that includes this accumulation enables the reconstruction of major oxygen and temperature trends throughout Earth’s history.

The carbon emissions of large igneous province magmatism are commonly associated with severe environmental crises. We developed a technique that used sedimentary mercury records to estimate these carbon fluxes through time and found that they are smaller and/or slower than assumed, which suggests that the influence of carbon-cycle feedback processes is underestimated in current models.

Through the detection of postcursors of shear waves diffracted at the core–mantle boundary, a zone of ultralow seismic velocities has been identified at the base of the mantle beneath the Himalayas. The presence of this zone is probably linked to a subducted slab remnant that is driving mantle flow in the region.

Earthquakes not only affect tree growth directly by causing physical injury to individual trees but also indirectly by inducing changes in forest habitats. We established linkage between tree-ring series and seismic disturbances and found that prominent and lasting seismic legacies in drier areas may be due to an increased infiltration of precipitation through earthquake-induced soil cracks.

An integrated model of mineral weathering and carbon cycling reveals the substantial influence that clay minerals originating from the weathering of magnesium-rich rocks have on Earth’s climate. This research indicates that this clay-forming process contributed to each Palaeozoic glaciation.

Analysis of sea temperatures using a four-dimensional spatio-temporal framework has revealed a great number of marine heatwaves occurring globally below the sea surface. These extreme events, which threaten the ecologically important epipelagic zone, have occurred increasingly frequently during the past three decades owing to ocean warming.

Deep-sea acidity data combined with ice-core carbon dioxide records reveal that an interplay between the two polar regions modulates ocean ventilation through various modes. These modes explain past variations in deep-sea carbon storage and atmospheric carbon dioxide on millennial timescales.

H₂, which is formed by the oxidation of iron in rocks, was likely a critical source of energy for early life. Analysis of natural rock samples from 3.5–2.7 billion-year-old komatiites, combined with geochemical data from a global database, quantifies the amount of H₂ likely to have been produced in Earth’s ancient oceans.

Megafloods are rare and hence difficult to predict. However, using a collation of historical flood observations across Europe, it is now shown that recent megafloods could have been anticipated — local surprises are in fact not surprising at the continental scale.

Swath radar maps of the subglacial landscape reveal how Antarctica’s geologic history has influenced the evolution of the ice sheet. The findings indicate the role of past interior ice streams in shaping ice-sheet growth and flow from Hercules Dome.

From a stalagmite that grew 14,000–8,500 years ago, isotopic data provide a detailed history of groundwater infiltration associated with a strengthening North American monsoon, as the climate transitioned from a cool dry late-glacial period into a warmer and wetter Early Holocene.

Accurate estimates of the land carbon sink are vital for informing climate projections and net-zero policies. Application of a strict filtering method to microwave satellite data enabled the evaluation of global vegetation biomass carbon dynamics for 2010–2019. The results highlight the role of demography in driving forest carbon gains and losses.

There are two competing hypotheses for the origin of oceanic plateaus: plume versus plate. Thermodynamic modelling of magmatism at Shatsky Rise, in the Pacific Ocean, now suggests that neither mechanism is adequate on its own and in fact plume–ridge interaction is required to explain the formation of this ocean plateau.

Phosphorus from intensive agriculture contributes to increased algal blooms, threatening ecosystems and drinking water sources. We found increasing dissolved phosphorus concentrations in more than 170 Great Lakes Basin streams, despite stable or decreasing total phosphorus levels. Higher latitudes experienced greater relative increases, potentially due to warmer winters and altered flow pathways.

Glacier ice contains high-pressure air bubbles, which burst into seawater as ice melts at tidewater glacier termini. Laboratory measurements found that these bubbles double the rate of ice melt. Theoretically, this effect could be even larger in a real glacier. However, bursting bubbles are currently neglected in models projecting sea level rise.

Analysis of mineral inclusions in magmas that crystallized before and after the Great Oxidation Event reveals marked changes in the oxidation state of sulfur — owing to the recycling into the mantle of sediments that had been geochemically altered at the surface by atmospheric events.

There is a large discrepancy between estimates of oceanic plastic input and the amount of plastic measured floating at the ocean surface. Model results show that this can be explained by large objects being underestimated in previous mass budget analyses, combined with lower input estimates.

Analysis of the microfossil content of sediment cores from areas where thick Arctic sea ice persists today reveals that a subpolar species associated with Atlantic water expanded deep into the Arctic Ocean during the Last Interglacial. This finding implies that summers in the Arctic were likely sea-ice-free during this period.