Earth and environmental sciences

  • Article
    | Open Access

    How early photosynthesizers managed oxidative stress remains relatively unresolved. Analyses of enzymes dealing with reactive oxygen species traces the evolutionary history of superoxide dismutases and finds evidence of CuZnSOD in the ancestor of all cyanobacteria, dating back to the Archaean.

    • Joanne S. Boden
    • , Kurt O. Konhauser
    •  & Patricia Sánchez-Baracaldo
  • Article
    | Open Access

    Methane emissions from oil and gas systems are underestimated in official inventories. Here the authors synthesize thousands of field measurements and develop an inventory-based model for a better understanding of why this underestimation exists and how it can be fixed.

    • Jeffrey S. Rutherford
    • , Evan D. Sherwin
    •  & Adam R. Brandt
  • Article
    | Open Access

    The linkage between temperature change and extinction rates in the fossil record is well-known qualitatively but little explored quantitatively. Here the authors investigate the relationship of marine animal extinctions with rate and magnitude of temperature change across the last 450 million years, and identify thresholds in climate change linked to mass extinctions.

    • Haijun Song
    • , David B. Kemp
    •  & Xu Dai
  • Article
    | Open Access

    COVID-19 has decreased power sector emissions globally and in the United States. Here the authors assess whether such reductions would have occurred in the United States in the absence of the pandemic, as well as the potential impact of COVID-19 on coal-fired power plant retirements through 2022.

    • Max Luke
    • , Priyanshi Somani
    •  & Stephen J. Lee
  • Article
    | Open Access

    This paper quantifies global urban water scarcity in 2016 and 2050 and explores potential solutions. One third to nearly half of the global urban population is projected to face water scarcity problems.

    • Chunyang He
    • , Zhifeng Liu
    •  & Brett A. Bryan
  • Article
    | Open Access

    The relative role of individual forcing events in long-term landscape evolution is challenging to measure in the field. Badlands offer special opportunities to quantify common, natural landscape dynamics on observational time scales.

    • Ci-Jian Yang
    • , Jens M. Turowski
    •  & Kuo-Jen Chang
  • Article
    | Open Access

    Silica formation in diatoms is of interest for a range of different subjects from biomimetics to oceanography. Here the authors study the formation of silicified extensions in diatoms and find that unlike cell wall elements, that form in the cytoplasm, the extensions have a different formation mechanism outside the cytoplasm.

    • Boaz Mayzel
    • , Lior Aram
    •  & Assaf Gal
  • Article
    | Open Access

    Climate change is expected to have impacts on human mortality, e.g. through increases in heat waves. Here, the author proposes a new metric to account for excess deaths from additional CO2 emissions, which allows to assess the mortality impacts of marginal emissions and leads to a substantial increase in the social costs of carbon.

    • R. Daniel Bressler
  • Article
    | Open Access

    Satellite observations reveal a significant positive trend in Earth’s energy imbalance, but the contributing drivers have yet to be understood. Here, the authors show that it is exceptionally unlikely that this trend can be explained by internal variability; instead, anthropogenic forcing and feedbacks cause the trend.

    • Shiv Priyam Raghuraman
    • , David Paynter
    •  & V. Ramaswamy
  • Article
    | Open Access

    Plant and soil C:N:P ratios are critical to ecosystem functioning, but it remains uncertain how plant diversity affects terrestrial C:N:P. In this meta-analysis of 169 studies, the authors find that plant mixtures can balance plant and soil C:N:P ratios according to background soil C:N:P.

    • Xinli Chen
    •  & Han Y. H. Chen
  • Article
    | Open Access

    Here the authors show that 2-aminoethylphosphonate (2AEP) mineralisation is widespread in the global ocean, operating independently of exogenous inorganic phosphate concentration. They propose 2AEP may be a major route for the regeneration of phosphate required to support marine primary production.

    • Andrew R. J. Murphy
    • , David J. Scanlan
    •  & Ian D. E. A. Lidbury
  • Article
    | Open Access

    The global water demands of irrigated agriculture are estimated through country surveys or through hydrological models, but both approaches are taxing. Here, the authors show that they can simply be estimated as a function of irrigated areas.

    • Arnald Puy
    • , Emanuele Borgonovo
    •  & Andrea Saltelli
  • Article
    | Open Access

    How acute deoxygenation events affect tropical marine ecosystems remains poorly understood. This study integrates analyses of coral reef benthic communities with microbial community sequencing to show how a deoxygenation event rapidly altered a shallow tropical coral reef ecosystem in the Caribbean.

    • Maggie D. Johnson
    • , Jarrod J. Scott
    •  & Andrew H. Altieri
  • Article
    | Open Access

    A historical reconstruction of water use in Egypt shows the change in relative use of Nile water versus virtual water import, especially in the highly consumptive agriculture sector. A range of future projections of water demand are offered based on several plausible socioeconomic scenarios.

    • Catherine A. Nikiel
    •  & Elfatih A. B. Eltahir
  • Article
    | Open Access

    This study combines ethnobotanical and epidemiological data to understand how social networks of seed exchange influence the genetic structure of the African cassava mosaic virus in Gabon. Results reveal contrasted patterns of viral diversity in patrilineal and matrilineal communities, consistent with cultural differences in modes of seed exchange.

    • Marc Delêtre
    • , Jean-Michel Lett
    •  & Charles Spillane
  • Article
    | Open Access

    The North Water polynya is a unique but vulnerable ecosystem, home to Indigenous people and Arctic keystone species. New palaeoecological records from Greenland suggest human abandonment c. 2200–1200 cal yrs BP occurred during climate-forced polynya instability, foreshadowing future ecosystem declines.

    • Sofia Ribeiro
    • , Audrey Limoges
    •  & Thomas A. Davidson
  • Article
    | Open Access

    Experiments and buoyancy calculations reveal that subduction of limestone results in massive carbon storage in arc lithosphere, forming an important carbon reservoir in convergent margins. Remobilization of this carbon reservoir during arc magma ascent may dominate carbon emissions at volcanic arcs.

    • Chunfei Chen
    • , Michael W. Förster
    •  & Yongsheng Liu
  • Article
    | Open Access

    This paper reveals that potassic alteration can be triggered by Na-rich fluids, indicating that pervasive sequential sodic and potassic alterations associated with mineralization in some of the world’s largest ore deposits may not necessarily reflect externally-driven changes in fluid alkali contents.

    • Gan Duan
    • , Rahul Ram
    •  & Joël Brugger
  • Article
    | Open Access

    Relationships between biodiversity and phosphorus cycling and the underlying processes are complex. Here the authors analyse a biodiversity manipulation experiment and an agricultural management gradient to show how plant and mycorrhizal fungal diversity promote phosphorus exploitation.

    • Yvonne Oelmann
    • , Markus Lange
    •  & Wolfgang Wilcke
  • Article
    | Open Access

    To explore the importance of local vs. global sulfur-cycle controls on variations in pyrite sulfur isotopes, the authors couple carbon-nitrogen-sulfur concentrations and stable isotopes of sediments from the Peruvian oxygen minimum zone, identifying a major role for the local organic carbon loading.

    • Virgil Pasquier
    • , David A. Fike
    •  & Itay Halevy
  • Article
    | Open Access

    How the Central American mountains influence tropical cyclone (TC) development in the eastern North Pacific is not well understood. Here, the authors use model simulations to show that on a seasonal timescale, these mountains interrupt moisture transport from the Caribbean Sea and as a result, reduce TC activity by up to 35%.

    • Dan Fu
    • , Ping Chang
    •  & Hylke E. Beck
  • Article
    | Open Access

    Plastics are major marine pollutants, and while research suggests that they can release potential harmful additives into seawater, how environmental conditions influence this is unknown. Here the authors determine that byproducts released from microplastics are less under deep-sea conditions versus surface.

    • Vincent Fauvelle
    • , Marc Garel
    •  & Richard Sempéré
  • Perspective
    | Open Access

    Many different methods have been developed to forecast climate phenomena like the El Nino-Southern Oscillation (ENSO) which makes a fair comparison of their capabilities crucial. In this perspective, the authors discuss how choices in the evaluation method can lead to an overestimated perceived skill of ENSO forecasts.

    • James S. Risbey
    • , Dougal T. Squire
    •  & Carly R. Tozer
  • Article
    | Open Access

    The deep North Pacific is the end of the road for global ocean circulation, but the circulation patterns and ventilation are poorly understood. Here the authors show that diffusive transports both along and across density layers play a leading role in returning 1,400 year old water to the surface.

    • Mark Holzer
    • , Tim DeVries
    •  & Casimir de Lavergne
  • Article
    | Open Access

    Forests can influence climate by affecting low cloud formation, but where and when this occurs is not well known. Here, the authors provide a global-scale assessment, based on satellite remote sensing observations, suggesting afforestation mostly increases low cloud cover which could potentially cool surface temperatures.

    • Gregory Duveiller
    • , Federico Filipponi
    •  & Alessandro Cescatti
  • Article
    | Open Access

    Meteorites from space often include denser polymorphs of their minerals, providing records of past hypervelocity collisions. An olivine mineral crystal was shock-compressed by a high-power laser, and its transformation into denser ringwoodite was time-resolved using an X-ray free electron laser.

    • Takuo Okuchi
    • , Yusuke Seto
    •  & Norimasa Ozaki
  • Article
    | Open Access

    Carbonate mineral aqueous solubility decreases as carbonates become more Mg-rich during subduction. Coupled with regional variations in amounts of carbon and water subducted, this explains discrepancies in estimates of carbon recycling, suggesting that only around a third returns to the surface.

    • Stefan Farsang
    • , Marion Louvel
    •  & Simon A. T. Redfern
  • Article
    | Open Access

    How tropical cyclones have varied in intensity and frequency in the past is not well known as longer records are rare. Here, the authors show that changes in observing practices explain the recorded century scale increase in Atlantic major hurricane frequency, and recent increases are not part of a century-scale trend.

    • Gabriel A. Vecchi
    • , Christopher Landsea
    •  & Thomas Knutson
  • Article
    | Open Access

    Lead toxicity poses a big hurdle for the commercialization of perovskite optoelectronics, hence reducing the environmental impact holds the answer for its future application. To tackle this challenge, the authors utilize germanium to reduce the lead content, enabling highly luminescent eco-friendly compound for LEDs.

    • Dexin Yang
    • , Guoling Zhang
    •  & Dawei Di
  • Article
    | Open Access

    Seismic imaging of subducted plates offers a way to improve plate tectonic reconstructions. Here, Braszus et al. use new ocean-bottom seismometer data from the Lesser Antilles to locate subducted spreading centres and faults thus providing a new understanding of the evolution of the Caribbean plate.

    • Benedikt Braszus
    • , Saskia Goes
    •  & Marjorie Wilson
  • Article
    | Open Access

    Freshwater salinisation is a growing water quality problem, but impacts and drivers across regional to global scales have been lacking. A new assessment of inter-regional freshwater salinisation demonstrates the importance of irrigation as a driver of salinisation.

    • Josefin Thorslund
    • , Marc F. P. Bierkens
    •  & Michelle T. H. van Vliet
  • Article
    | Open Access

    Reconciling the Snowball Earth hypothesis with sedimentological cyclicity has been a persistent challenge. A new cyclostratigraphic climate record for a Cryogenian banded iron formation in Australia provides evidence for orbital forcing of ice sheet advance and retreat cycles during Snowball Earth.

    • Ross N. Mitchell
    • , Thomas M. Gernon
    •  & Xiaofang He
  • Article
    | Open Access

    This paper placed the identified Mariana type ophiolite within a global tectonic re-organization at ca. 530-520 Ma. Similar ophiolites, together with other geological and chemical proxies, newly constrained the timing of establishment of modern plate tectonics, along with its links to surficial changes that characterize the contemporary Earth.

    • Jinlong Yao
    • , Peter A. Cawood
    •  & Peng Wang
  • Article
    | Open Access

    It has been suggested that younger people care more about climate change than older people. Here, the authors present ten year panel data from New Zealand and show that despite a generation gap in starting levels, climate change beliefs have increased at similar rates across ages over the 2009-2018 period.

    • Taciano L. Milfont
    • , Elena Zubielevitch
    •  & Chris G. Sibley
  • Article
    | Open Access

    Climate models project an intensification of extreme precipitation under climate change, but this effect is difficult to detect in the observational record. Here, the authors show that a physically interpretable anthropogenic impact on extreme precipitation is detectable in global observational data sets.

    • Gavin D. Madakumbura
    • , Chad W. Thackeray
    •  & Alex Hall
  • Article
    | Open Access

    Nitrogen fixation by diazotrophs is critical for marine primary production. Using Tara Oceans datasets, this study combines a quantitative image analysis pipeline with metagenomic mining to provide an improved global overview of diazotroph abundance, diversity and distribution.

    • Juan José Pierella Karlusich
    • , Eric Pelletier
    •  & Rachel A. Foster