Variations in winter sea ice concentrations in the Barents-Kara seas have been linked with extreme heat events over Eurasia in following spring over the past two decades, suggest statistical analyses of observational data.

Microbial anaerobic oxidation of methane may not substantially mitigate projected warming-induced emissions of methane from marine hydrate-bearing sediments, according to a coupled hydraulic-thermodynamic-geomechanical hydrate model.

Following the latest Permian extinction, nutrient availability from enhanced continental weathering enabled biological recovery in the ocean, according to K-Ar dating of clay minerals and nitrogen isotope analyses from high northern latitudes.

Elevated methyl and ethyl iodide concentrations in bottom waters may be linked to diatom aggregates and phytodetritus from the spring bloom settling to the sea floor, according to shipborne observations and laboratory-based incubation experiments in the Bering and Chukchi Seas and Funka Bay, Japan.

Over the past four decades, Arctic Amplification - the ratio of Arctic to global warming - has been much stronger than thought, and is probably underestimated in climate models, suggest analyses of observations and the CMIP5 and CMIP6 simulations.

Warming in the Gulf of Maine, western North Atlantic, since the late 1800s reversed a 900-year cooling trend, likely as a result of increasing atmospheric greenhouse gases, according to ocean temperature and water mass reconstructions from bivalves and climate model simulations.

Students who completed the online version of an introductory course on climate change performed 2% worse than those who completed the in-person version, according to a study of 1790 undergraduate students in California, USA.

Rainfall in subtropical Australia and sea salt deposited in snowfall at the Law Dome ice core site in East Antarctica are linked through a synoptic weather pattern that bridges the two regions, according to a synoptic typing data analysis.

Small-scale inland and coastal fisheries improve physical and economic access to food for communities in Malawi, Tanzania and Uganda, according to analyses of nationally representative data.

Rapid warming of coastal waters in the Northwest Atlantic is affecting local fisheries and ecosystems. Our article revealed the role of the Gulf Stream in this warming, thereby helping to define environmental management in New England and inspiring students in Brazil.

The floating ice shelves around Antarctica are key to buttressing land-based ice. Observations, simulations and analyses from around Antarctica now identify mechanisms that lead to basal melting of these vulnerable shelves.

A recent study dating Viking presence in America to a precise year was only possible thanks to long-term conservation of archaeological finds. It also arose from curiosity, interdisciplinarity and recognition of emerging techniques. These factors highlight the importance of archiving materials and asking the right questions in research on the entanglements of climate and history.

Having shed new light on an old mystery—how nine Russian mountaineers perished in the Urals in 1959—Alexander Puzrin and Johan Gaume got hooked. Three expeditions later it is clear that avalanches are not exceptional at Dyatlov Pass.

When an earthquake in southern France caused the ground to rupture—a phenomenon not known during the last 25 years in the region—the earthquake science community worked together to determine the implications for hazard assessment. Now we must maintain that spirit of co-operation for the future.

In 2021, 1348 reviewers wrote a peer review report for Communications Earth & Environment. We would like to express our thanks to all of them.