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The influence of surface ponding on the interior of ice shelves is currently unknown. Here, the authors combine surface and borehole geophysics on the Larsen C Ice Shelf, Antarctica, with remote sensing and modelling and show how pond refreezing increases ice shelf density and temperature.

Ozone-depleting substances emitted through human activities cause large-scale damage to the stratospheric ozone layer, and influence global climate. An analysis of unpolluted air sampled from Tasmania and firn snow reveals the emergence of four new ozone-depleting substances in the atmosphere since the 1960s.

Projecting the future retreat and thus global sea level contributions of Antarctica’s Pine Island Glacier is hampered by a poor grasp of what controls flow at the ice base. Here, via high-resolution ice-radar imaging, the authors show diverse landscapes beneath the glacier fundamentally influence ice flow.

An observationally calibrated ice sheet–shelf model suggests that global warming of 3 °C will trigger rapid Antarctic ice loss, contributing about 0.5 cm per year of sea-level rise by 2100.

Three techniques for estimating mass losses from the Greenland Ice Sheet produce comparable results for the period 1992–2018 that approach the trajectory of the highest rates of sea-level rise projected by the IPCC.

The degree to which debris-covered glaciers record past environmental conditions is debated. Here, the authors show that obliquity-paced variations in solar radiation over the past ∼220 ka are expressed in Mullins glacier as repetitive changes in englacial debris and corresponding surface topography.

Interactive climate and ice sheet simulations project substantial East Antarctic ice loss under high emissions, amplified regional sea level rise in the Pacific, and enhanced northern latitude warming despite dampened global mean temperature rise.

Greenland ice sheet melt is currently the largest single contributor to sea-level rise. This work combines observations and theory to show that Greenland ice sheet imbalance with recent climate (2000–2019) has already committed at least 3.3% ice volume loss, equivalent to 274 mm of global sea-level rise.

Using historical aerial photographs and new bed topography data, accelerating changes on Kennicott and Root Glaciers, Alaska since 1938 are documented. These observations inform projections showing 38–63% mass loss by 2100, depending on future climate.

The bed of the West Antarctic ice sheet is, in places, more than 1.5 km below sea level. Radio-echo sounding data from the Weddell Sea sector of Antarctica reveal a large subglacial basin immediately upstream of the ice sheet’s grounding line, with a steep reverse gradient and a smooth floor.

Levels of five chlorofluorocarbons rose in the atmosphere from 2010 to 2020 despite their production being banned by the Montreal Protocol, probably arising as by-products of hydrofluorocarbon production, according to analysis of abundance and emissions data.

An annually resolved ice-core record from West Antarctica indicates that warming driven by local insolation resulting from sea-ice decline began in that region about 2,000 years before warming in East Antarctica, reconciling two alternative explanations for deglacial warming in the Southern Hemisphere.

Trends in global H₂ sources and sinks are analysed from 1990 to 2020, and a comprehensive budget for the decade 2010–2020 is presented.

Terrestrial ecosystem productivity is widely accepted to be nutrient limited. A series of standardized nutrient addition experiments, carried out on grasslands on five continents, suggests aboveground grassland productivity is commonly limited by multiple nutrients, including potassium and micronutrients.

Ice sheet freshwater discharge interacts with the climate and affects the ice sheet’s sensitivity to climate change. This study shows that the overall feedback shifts from positive to negative as the pace of future warming intensifies

While it may feel cold to the touch, Sheng Fan and David Prior explain that ice on Earth is relatively hot. Understanding ‘hot’ ice physics during deformation is critical in determining future sea-level rise.

Climate and ice-sheet modelling that includes ice fracture dynamics reveals that Antarctica could contribute more than a metre of sea-level rise by 2100 and more than 13 metres by 2500, if greenhouse gas emissions continue unabated.

Surface fractures that intersect glacial streams can propagate deeply in ice sheets and can increase their dynamic instability as melting intensifies, according to a new observationally-constrained modelling study of the Greenland Ice Sheet.

This study uses radio-echo sounding measurements, ice-core data and models to map the spatial variation in ice-crystal orientation in the northeast Greenland Ice Stream and shows how it potentially affects the ice-flow dynamics in this region.

The observation of non-mass-dependent sulphur isotope ratios in sedimentary rocks more than ∼2.4 billion years old and the disappearance of this signal in younger sediments is taken as evidence for the transition from an anoxic to oxic atmosphere around 2.4 Gyr ago. But now, the preservation of a non mass-dependent signal that differs from that of preceding and following periods in the Archean is demonstrated. The findings support the original idea of an anoxic early atmosphere before 2.4 Gyr ago, and at the same time identifies variability within the isotope record that suggests changes in pre-2.4 Gya atmospheric pathways for non-mass-dependent chemistry and in the ultraviolet transparency of an evolving early atmosphere.

Whether changes in atmospheric circulation over West Antarctica during the past few decades are part of a longer-term trend is unclear. Ice cores reveal a significant increase in the oxygen isotopes from precipitation over the past 50 years, but the anomaly cannot be distinguished from natural climate variability.

Subglacial meltwater channels beneath the Antarctic Ice Sheet have been reported, but the nature and distribution of these meltwater pathways are unclear. Remote sensing observations reveal persistent channelized features beneath the Filchner–Ronne Ice Shelf in West Antarctica, suggesting widespread channelized flow driven by melting.

Multi-year field experiments across six continents suggest that insects have an important contribution to decomposition and carbon release from forest deadwood.

It remains unclear whether exotic and native species are functionally different. Using a global grassland experiment, Seabloomet al. show that native and exotic species respond differently to two globally pervasive environmental changes, addition of mineral nutrients and alteration of herbivore density.

New, non-compliant emissions of ozone-depleting substances and very short-lived substances challenge the continued success of the Montreal Protocol, and, thereby, the timescale for the recovery of the ozone layer. This Review discusses recent trends in anthropogenic and natural ozone-depleting substance and very short-lived substance emissions, and examines their potential impact on atmospheric ozone concentrations.

Synthetic aperture radar interferometry reveals that 19 Gt of ice is lost per year from glaciers in South America — mostly from Patagonia — contributing 0.04 mm annually to global sea-level rise.

Methane is an important greenhouse gas, responsible for about 20% of the warming induced by long-lived greenhouse gases since pre-industrial times. A compilation of observations and results from chemical transport, ecosystem and climate chemistry models suggests that a rise in wetland and fossil fuel emissions probably accounts for the renewed increase in global methane levels after 2006.

We anticipate that conventional management approaches will be insufficient to protect coral reefs, even if global warming is limited to 1.5 °C. Emerging technologies are needed to stem the decline of these natural assets.

Antarctic ice-core records and atmospheric transport modelling used here show that the 13th-century rise of Māori culture in New Zealand led to a threefold increase of atmospheric black carbon.

The Gravity Recovery and Climate Experiment (GRACE) mission, launched in 2002, allows monitoring of changes in hydrology and the cryosphere with terrestrial and ocean applications. This Review Article focuses on its contribution to the detection and quantification of climate change signals.

The 100-year Global Warming Potential of hydrogen falls in the range 11.6 ± 2.8, according to chemistry-model estimates, through its chemical impact on methane, ozone and stratospheric water vapor. It is therefore important to avoid leakages in a hydrogen economy, to help mitigate climate change.

Experimental data collected from 40 grasslands on 6 continents show that nutrients and herbivores can serve as counteracting forces to control local plant diversity; nutrient addition reduces local diversity through light limitation, and herbivory rescues diversity at sites where it alleviates light limitation.