Top 50: Earth and Planetary Sciences

Microplastic (MP) pollution in polar regions is a growing environmental concern, yet little is known regarding the role of sea-ice as a sink and transport vector of MPs. Here, the authors show that MPs in sea-ice have no uniform polymer composition and observe unique MP patterns in different sea-ice horizons.

Ureilites are a type of meteorite that are believed to be derived from a parent body that was impacted in the early solar system. Here, the authors analyse inclusions within diamonds from a ureilite meteorite and find that they must have formed at above 20 GPa suggesting the parent body was Mercury- to Mars-sized.

Marine heatwaves are climatic extremes with devastating and long-term impacts on marine ecosystems, fisheries and aquaculture. Here the authors use a range of ocean temperature observations to identify significant increases in marine heatwaves over the past century.

Accurate near-term predictions of global temperatures are required to determine some of the key impacts of climate change. Here the authors develop a novel probabilistic forecast system that shows anomalously warm temperatures for the next years with increased risk of extreme warming.

UNESCO World Heritage located in low-lying coastal areas is increasingly at risk from flooding and erosion due to sea-level rise. This study shows that up to 82% of cultural World Heritage sites located in the Mediterranean will be at risk from coastal flooding and over 93% from coastal erosion by 2100 under high-end sea-level rise.

Rising seas are a legacy of present and future climate change. Here the authors show that under the Paris Agreement, emissions in the next decades have a strong influence on the amount of sea level rise in the centuries to come, with the uncertainty dominated by ice-sheet contributions.

Whether accelerated Arctic warming is favorable for more frequent severe winter weather remains controversial. Here the authors present an observational analysis that links Arctic warming to severe winter weather, showing that extreme weather is 2–4 times more likely in the eastern US when the Arctic is warm.

The Paris Agreement includes bottom-up pledges and top-down warming threshold. Under this setting where countries effectively choose their own fairness principle, this article assesses the global warming implied by each Nationally Determined Contribution to inform the future ratcheting-up process.

Permafrost carbon feedback modeling has focused on gradual thaw of near-surface permafrost leading to greenhouse gas emissions that accelerate climate change. Here the authors show that deeper, abrupt thaw beneath lakes will more than double radiative forcing from permafrost-soil carbon fluxes this century.

Irrigation increases the intensity of heatwaves over the North China Plain but how this will be exacerbated by climate change has not been quantified. Here the authors show that irrigation enhances magnitude of extreme wet-bulb temperature and intensity of heatwaves in this region.

Achondritic meteorites can record volcanism and crust formation on planetesimals in the early Solar System. Here, the authors date the Northwest Africa 11119 meteorite with an Al-Mg age of 4564.8 ± 0.3 Ma indicating that this is the earliest evidence of silicic volcanism in the Solar System to date.

Long-term records of jet stream variability are needed to place recent mid-latitude extreme weather events into a historical context. Here, using tree-ring records from Europe, the authors reconstruct variability in the latitudinal position of the high-summer North Atlantic Jet since 1725 CE.

Quantifying the vulnerability of tidal marsh ecosystems to relative sea-level rise (RSLR) is essential if the threat is to be mitigated. Here, the authors analyze the response of Great Britain’s tidal marshes to RSLR during the Holocene and predict an almost inevitable loss of this ecosystem by 2100 under rapid RSLR scenarios.

Accelerated global warming in the Arctic might have profound impacts on mid-latitude weather particularly in winter, although the evidence for an effect also in summer is also growing. Here Coumou et al. show that these interactions could lead to more persistent hot-dry extremes in mid-latitudes.

The Cassini spacecraft has provided an unprecedented characterisation of seasonal changes on Saturn. Here the authors describe the development of a warm polar vortex in Saturn’s northern summer, and show that the hexagon extends hundreds of kilometres from the troposphere into the stratosphere.

The West Antarctic Ice Sheet sits atop an extensional rift system with volcano-like features, yet we do not know if any of these volcanoes are active, because identifying subglacial volcanism remains a challenge. Here, the authors find evidence in helium isotopes that a large volcanic heat source is emanating from beneath the fast-melting Pine Island Ice Glacier.

Lamprophyres represent hydrous alkaline mantle melts that are a unique source of information about the composition of continental lithosphere. Here the authors use isotopic compositions of lamprophyres to map a hidden terrain boundary and an unknown fragment of Armorica in the mantle lithosphere of southwest Britain.

The surface types that comprise the dark zone of the Greenland Ice Sheet, an area of bare ice with low albedo, are unknown. Here, the authors use UAV imagery to show that, during the melt-season, biologically active surface impurities are responsible for spatial albedo patterns and the dark zone itself.

Coral reefs provide significant coastal protection from storms but they have experienced significant losses. Here the authors show that the annual damages from flooding would double globally without reefs and they quantify where reefs provide the most protection to people and property.

The extent to which the onset of bioturbation affected global biogeochemistry during the Palaeozoic remains unclear. Here, the authors integrate bioturbation into the COPSE model, compare output with geochemical proxies, and suggest shallow burrowing contributed to a global low oxygen state during the early Cambrian.

Lakes on the Greenland Ice Sheet transfer water to the bed when they drain, but the impact is unknown. Here, the authors use a 3D model to show that lakes drain when fractures form, causing a chain reaction in which cascading lake drainages extend inland and deliver water to previously isolated regions of the bed.

Permafrost thaw poses a serious threat to the sustainable development of Arctic communities. Here the authors show that most fundamental Arctic infrastructure and population will be at high hazard risk, even if the Paris Agreement target is achieved.

Storm runoff extremes dominate flash flood formation and generation, posing a grand threat to ecosystems and communities across the world. Here the authors show that current projected response of these storm runoff extremes to climate and anthropogenic changes are underestimated.

Arctic ecosystems are at threat due to the rapid nature of climate change and Arctic amplification. Here, the authors show that the watershed of Lake Hazen, the Arctic’s largest lake by volume, has undergone dramatic changes in response to as little as a ~1°C increase in summer air temperatures.

The rapid growth of South–South trade reflects a new phase of globalization. Here the authors show that some energy-intensive production activities, particularly raw materials and intermediate goods, and related CO₂ emissions are relocating from China and India to other developing countries.

Fires cause large perturbations to terrestrial carbon cycle through direct carbon emissions. Here the authors combine several models and measurement datasets and show that fires can indirectly worsen the carbon loss through the net negative impacts on ecosystem productivity from fire ozone and aerosols.

Land-based mitigation for meeting the Paris climate target must consider the carbon cycle impacts of land-use change. Here the authors show that when bioenergy crops replace high carbon content ecosystems, forest-based mitigation could be more effective for CO₂ removal than bioenergy crops with carbon capture and storage.

The climate impacts of deforestation due to changes in biogenic volatile organic compound emissions, which act as short-lived climate forcers (SLCFs), are poorly understood. Here the authors show that including the impact SLCFs increases the projected warming associated with idealised deforestation scenarios.

Climate deterioration towards desertification in North Africa following the African Humid Period has previously been associated with the emergence of pastoralism. Here, using a climate-vegetation model, the authors show that pastoralism in fact likely slowed the deterioration of orbitally-driven climate change.

Martian dust is globally enriched in S and Cl and has a distinct mean S:Cl ratio. Here the authors identify that the largest potential source region for Martian dust based on analysis of elemental abundance data may be the Medusae Fossae Formation.

Crystals can record the timing of volcanic eruptive triggers at depth by examining their zoning histories. Here, the authors analyse clinopyroxene crystal zoning from eruptions at Mount Etna, Italy from 1974-2014 and show that the intrusion of magma can trigger an eruption within 2 weeks of arrival.

Columnar joints in lavas form during cooling, but the temperature this occurs at is unclear. Here, the authors perform thermo-mechanical experiments on basaltic rocks to examine the temperature of columnar joints in lavas and find that failure occurs at 890–840 °C, which is below the solidus temperature of 980 °C.

Climate oscillations such as El Niño Southern Oscillation may impact global crop production. Here, the authors, using a unified framework of multiple climate oscillations, find that from 1961 to 2010 over two-thirds of the global cropland is located where crop productivity is influenced by climate oscillations.

It remains unclear whether surface water partial pressure of CO₂ (pCO₂) in continental shelves tracks with increasing atmospheric pCO₂. Here, the authors show that pCO₂ in shelf waters lags behind rising atmospheric CO₂ in a number of shelf regions, suggesting shelf uptake of atmospheric CO₂.

A warmer and drier climate will affect wildfire activity but the climate-fire relationship could change under warming. Here the authors use models with a non-stationary climate-fire relationship to show that to avoid doubling the burned area in the coming decades we must stay below 1.5 °C Paris target.

Research and debate are intensifying on complementing CO₂ emissions reductions with hypothetical climate geoengineering techniques. Here, the authors assess their potentials, uncertainties and risks, and show that they cannot yet be relied on to significantly contribute to meeting the Paris Agreement temperature goals.

State-of-the-art climate models disagree on the magnitude of Arctic climate change. Here the authors show that the principle processes driving the disagreement operate locally in sea ice retreat regions, necessitating comprehensive observations to improve our understanding of atmosphere-ocean-sea ice energy exchanges.

Carbon capture and storage can help reduce CO₂ emissions but the confidence in geologic CO₂ storage security is uncertain. Here the authors present a numerical programme to estimate leakage from wells and find that under appropriate regulation 98% of injected CO₂ will be retained over 10,000 years.

Groundwater resources are coming under increasing pressure leading to water quality loss. Here, the authors find that recent groundwater pumping has led to increasing arsenic concentrations in the San Joaquin Valley, California aquifers from arsenic residing in the pore water of clay strata released by overpumping.

Imaging the internal structure of faults remains challenging using conventional seismometers. Here, the authors use fibre-optic cables used for telecommunications to obtain strain data and identify faults and volcanic dykes in Iceland and suggest that fibre-optic cables could be used for hazard assessment.

Knowledge of surface-ocean circulation in the Atlantic over the late Holocene is incomplete. Here, the authors show that Atlantic Ocean surface-circulation varied in concert with Western Hemisphere rainfall anomalies on centennial timescales and that this link played an essential role during the Little Ice Age.

As the global climate becomes warmer, the associated rising sea level could pose significant threats to island and coastal communities. Here the authors show that internal climate variability plays a key role in determining this sea level rise, especially in the next few decades.

Anticrack propagation in snow results from the mixed-mode failure and collapse of a buried weak layer and can lead to slab avalanches. Here, authors reproduce the complex dynamics of anticrack propagation observed in field experiments using a Material Point Method with large strain elastoplasticity.

ENSO is losing predictive power of west US coast precipitation. Here the authors identify a new inter-hemispheric teleconnection that promises earlier and more accurate prediction.

The relative impacts of changes in North Pacific and North Atlantic sea surface temperature on Arctic climate are not well defined. Here the authors find that Arctic surface temperatures are more sensitive to changes in North Pacific heat flux as a result of stronger modulations in poleward moisture and latent heat transport.

The impact of plastic debris floating at the sea surface on the lowest trophic levels of the food web remains unknown. Here, using leaching experiments, the authors show that plastics release dissolved organic carbon into the ambient seawater that is rapidly taken up by marine microbes stimulating their growth.

Despite decades of research, the sequence of events leading to the deglacial atmospheric CO₂ rise remains unclear. Menviel et al. show that Southern Ocean convection driven by intensified Southern Hemisphere westerlies during Heinrich stadial 1 can explain the abrupt pCO₂ rise and changes in atmosphere and ocean carbon isotopes.