Reviews & Analysis

Mediation by iron minerals in the non-biological production of nitrous and nitric oxides may have driven the nitrogen cycle in the Archean ocean. This system may also have shaped the function and composition of the early marine ecosystem.

Anthropogenic nitrogen deposition is known to affect forest soil respiration, but it remains unclear how soil respiration responds to nitrogen deposition over time. Monitoring of CO₂ emissions over 9–13 years of nitrogen-addition treatments in three tropical forests in southern China reveals a three-phase pattern of soil respiration.

Greening of the planet has increased global surface water availability, but vegetation changes can have diverse local and remote impacts across different regions.

The spatial and temporal geochemical variability of alkaline hydrothermal systems in shallow waters could support prebiotic chemical reactions required for the emergence of life.

Microplastics and nanoplastics may affect cloud formation processes by acting as ice-nucleating particles and cloud condensation nuclei.

Satellite measurements show that dust emission is enhanced following large wildfires, producing considerable dust loadings for days to weeks over normally dust-free regions. These sequential fire and dust extremes will likely become more frequent and severe under global warming, having increased societal and ecological impacts.

In rare and sometimes highly destructive cases, faults rupture faster than the seismic waves generated can travel. A global investigation of earthquake rupture speeds reveals that these events occur much more frequently than previously thought.

Large channels of meltwater snake beneath the ice in the Weddell Sea region of Antarctica. This water affects the speed of ice flow above and the melt rate of the ice when it reaches the ocean, having a direct role in the response of Antarctica to climate change.

Submarine gas hydrates in temperate and tropical oceans are probably not large sources of atmospheric methane emissions at present, suggests a study of methane sources along the Atlantic and Pacific coasts of the USA.

Melting of the edges of the Greenland ice sheet by the ocean since 1979 is — counterintuitively — controlled almost as much by air temperature as by ocean temperature.

Enhanced formation of clay in marine sediments in the lead up to the end-Permian mass extinction likely pulled the Earth back into a hot, high-CO₂ state similar to that of the Precambrian.

Cellular modelling and geochemical analyses reveal that a dominant group of phytoplankton changed their carbonate production as atmospheric CO₂ levels declined from peak levels in the warm early Eocene, hinting at a positive feedback in the global carbon cycle.

Controversy pervaded the June 2022 UN Ocean Conference, with partisan alliances forming around burgeoning environmental and social issues. Yet, out of the talks, emerged strong aspirations across UN states and other stakeholders to restore and protect the ocean.

Enhancing natural subsurface hydrogen production through water injection could make a substantial contribution to achieving the low-carbon energy transition that is required to limit global warming.

Seismometers on the NASA InSight lander have identified unusual signals from meteoroid impacts on Mars. Impact locations were confirmed by satellite images of new craters at these sites and directly constrain the martian interior, confirming its crustal structure and ground-truthing the scaling of impact-induced seismicity.

Bedrock composition can play a critical role in determining the structure and water demand of forests, influencing their vulnerability to drought. The properties of bedrock can help explain within-region patterns of tree mortality in the 2011–2017 California drought.

Modelling of the effect of reservoirs on the climate through time (1900 to 2060) revealed that although carbon emissions peaked in 1987, reservoir-induced radiative forcing will continue to rise for the next decades. Over time, reservoir emissions are shifting from carbon dioxide to methane-dominated pathways, on which knowledge is largely lacking.

Thwaites Glacier in Antarctica is losing mass and has the potential to cause substantial sea level rise. New seabed imagery indicates that the glacier previously retreated at double its current rate, implying that mass loss could accelerate in the near future.

The colonization of Earth landmasses by vascular plants around 430 million years ago substantially impacted erosion and sediment transport mechanisms. This left behind fingerprints in magmatic rocks, linking the evolution of Earth’s biosphere with its internal processes.