Volume 16 Issue 8, August 2023

Admission to doctoral study is a crucial step in the academic pipeline, but discriminatory procedures can disproportionately impact students from ethnic minority backgrounds. We show how these policies contribute to inequity in the geosciences and propose strategies for change.

A 3-year field experiment suggests plant responses to elevated CO₂ in phosphorus-limited grasslands depends on the biogeochemical interplay between soil microbes and plants.

The chemical weathering of silicate rocks plays a central role in stabilizing our climate through CO₂ drawdown. Li isotopic evidence from a prolonged Eocene warming event suggests clay formation may disrupt this feedback on intermediate timescales.

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.

Two contrasting sinuosity patterns were identified in lowland rivers on Earth and Mars. The channel sinuosity either substantially increases or remains constant towards the coast. These bimodal patterns reflect the age of the channels and their lateral migration rates, which are associated with sediment supply and discharge variability.

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.

Glacier retreat in Greenland not only changes the primary productivity of downstream fjord ecosystems but also the ecosystem structure and functioning, according to seasonal sampling of two downstream fjords.

The asteroid Ryugu experienced aqueous alteration under changing temperature and redox conditions, according to an isotopic analysis of secondary calcite and dolomite grains in samples from Ryugu obtained by the Hayabusa2 spacecraft.

Atmospheric short-wave absorption due to wildfire smoke is caused predominantly by dark brown carbon particles, according to observations from smoke plumes in the United States.

A 3D global marine plastic mass budget suggests that larger items contribute more than 95% of buoyant plastics by mass and are longer lived than previously estimated, which suggests there is no missing sink of marine plastic pollution.

Anthropogenic greenhouse gases and aerosols have counteracting effects on heat uptake and interbasin transport in the ocean, according to an ensemble of climate model simulations.

The competition between grassland vegetation and microbes for phosphorus controls how plant productivity responds to elevated CO₂, according to free-air CO₂ enrichment experiments on phosphorus-limited grasslands.

Grasses contribute more than half of the soil organic carbon across tropical savannas, according to a case study in South Africa combined with a synthesis of data from tropical savannas globally.

Orbital precession played a more important role than obliquity during Late Pleistocene swings in ice-sheet extent, according to an analysis of benthic oxygen isotope records with precise age constraints.

The warm Last Interglacial led to a seasonally ice-free Arctic Ocean and a transformation to Atlantic conditions, according to planktic foraminifera records from central Arctic Ocean sediment cores.

The long duration of the Middle Eocene Climatic Optimum, compared with other transient Eocene warming events, can be explained by an increase in clays forming from the weathering of silicate minerals, according to lithium isotope records of marine carbonates.

Himalayan valley-floor widths are controlled by long-term tectonically driven exhumation, rather than by water discharge, according to an analysis of valley-floor width and exhumation rate observations.

Spatial patterns of channel sinuosity near river outlets reflect the interplay between the channel migration rate and the avulsion timescale, according to sinuosity measurements of lowland rivers on Earth and Mars and channel evolution simulations.