Earth and environmental sciences

  • Article
    | Open Access

    Global climate changes triggered by massive output of greenhouse gases led to mass extinctions in Earth’s past. Here, the authors show that widespread release of methane at the time of the end-Triassic mass extinction was caused by interaction of a Large Igneous Province with sedimentary host-rocks.

    • Manfredo Capriolo
    • , Andrea Marzoli
    •  & Csaba Szabó
  • Article
    | Open Access

    The awareness of rock shape dependence in rockfall hazard assessment is growing, but experimental and field studies are scarce. This study presents a large data set of induced single block rockfall events quantifying the influence of rock shape and mass on its complex kinematic behaviour.

    • Andrin Caviezel
    • , Adrian Ringenbach
    •  & Perry Bartelt
  • Article
    | Open Access

    Harmful algal and bacterial blooms are increasingly frequent in lakes and rivers. From the Sydney Basin, Australia, this study uses fossil, sedimentary and geochemical data to reveal bloom events following forest ecosystem collapse during the end-Permian event and that blooms have consistently followed warming-related extinction events, inhibiting the recovery of freshwater ecosystems for millennia.

    • Chris Mays
    • , Stephen McLoughlin
    •  & Vivi Vajda
  • Article
    | Open Access

    Chemically variable primitive basalts undergo mixing during ascent from the mantle. Here the authors show observations from magma–magma reaction experiments which demonstrate how isothermal mixing between chemically variable basalts creates and modifies crystal cargoes erupted in oceanic settings.

    • David A. Neave
    • , Philipp Beckmann
    •  & François Holtz
  • Article
    | Open Access

    Sea spray aerosol (SSA) are an important way through which oceans can influence the atmosphere’s radiative properties. Here, the authors present measurements taken over a 42,000 km ship cruise in the Atlantic and Pacific Ocean and show that SSA number concentrations vary over a 24-hour cycle, possibly linked to surface water bubble-bursting dynamics.

    • J. Michel Flores
    • , Guillaume Bourdin
    •  & Ilan Koren
  • Article
    | Open Access

    Latitudinal ecosystem boundaries in the global upper ocean may be driven by many factors. Here the authors investigate pole-to-pole eukaryotic phytoplankton metatranscriptomes, gene co-expression networks, and beta diversity, finding that geographic patterns are best explained by temperature gradients.

    • Kara Martin
    • , Katrin Schmidt
    •  & Thomas Mock
  • Article
    | Open Access

    Low-frequency earthquakes are a series of small earthquakes with lower dominant frequencies than ordinary earthquakes. By comparing the simulated earthquakes with the real data, we find that low-frequency earthquakes represent an earthquake rupture process that arrests spontaneously.

    • Xueting Wei
    • , Jiankuan Xu
    •  & Xiaofei Chen
  • Article
    | Open Access

    There is much uncertainty on use and impact of pesticides in organic agriculture. Here, the authors compare pesticide use in conventionally and organically managed fields in Kern County (US), finding that organic fields are less likely to be treated but, when they are, they receive similar pesticide amount as the conventional fields.

    • Ashley E. Larsen
    • , L. Claire Powers
    •  & Sofie McComb
  • Article
    | Open Access

    Global demand for “blue food” is growing. In this quantitative synthesis, the authors analyse global seafood demand and project trends to 2050, finding considerable regional variation in the relationship between wealth and consumption.

    • Rosamond L. Naylor
    • , Avinash Kishore
    •  & Beatrice Crona
  • Article
    | Open Access

    Ultramafic olivine-rich achondrites provide insight into the missing mantle problem in the asteroid belt. The petrology and geochemistry of these samples suggests they are related to Vesta or the Vestoids.

    • Zoltan Vaci
    • , James M. D. Day
    •  & Andreas Pack
  • Article
    | Open Access

    Modelling and sea surface temperature proxy data from the Weddell Sea document a 3–4 °C drop coinciding with the Early Cretaceous Weissert Event. Temperature data worldwide confirm a 3.0 °C global mean surface cooling, equivalent to a ~40% drop in atmospheric pCO2, favouring local polar ice.

    • Liyenne Cavalheiro
    • , Thomas Wagner
    •  & Elisabetta Erba
  • Article
    | Open Access

    Root-mycorrhizal interactions could help explain the heterogeneity of plant responses to CO2 fertilisation and nutrient availability. Here the authors combine tree-ring and metagenomic data to reveal that tree growth responses to increasing CO2 along a soil nutrient gradient depend on the nitrogen foraging traits of ectomycorrhizal fungi.

    • Peter T. Pellitier
    • , Inés Ibáñez
    •  & Kirk Acharya
  • Article
    | Open Access

    Activated sludge (AS) systems in wastewater treatment plants (WWTPs) contain high concentration of viruses. Here, the authors apply a systematic metagenomic pipeline and retrieve a catalogue of around 50,000 prokaryotic viruses from samples of six WWTPs, revealing a large and uncharacterized viral diversity in AS communities.

    • Yiqiang Chen
    • , Yulin Wang
    •  & Tong Zhang
  • Article
    | Open Access

    Phytoplankton form the base of the marine ecosystem but current ocean models used for climate change projections are too simple to assess potential changes in plankton community structure. This study analyses a complex ecosystem model with 35 phytoplankton types to evaluate the changes in phytoplankton community composition, turnover and size structure over the 21st century.

    • Stephanie A. Henson
    • , B. B. Cael
    •  & Stephanie Dutkiewicz
  • Article
    | Open Access

    How much the potential intensity of tropical cyclones (TCs) increases in warmer environments is not well known. Here, the authors show that TC rainfall rates have increased by 1.3% per year between 1998 and 2018, a trend that is mainly driven by stronger rainfall in the outer-core region of TCs.

    • Oscar Guzman
    •  & Haiyan Jiang
  • Article
    | Open Access

    Crop diversification could be important for food security. Here, using methods from network science, the authors find that a positive relationship between crop diversity and nutritional stability globally does not necessarily equate to improving nutritional stability in a given country.

    • Charlie C. Nicholson
    • , Benjamin F. Emery
    •  & Meredith T. Niles
  • Article
    | Open Access

    Warming will affect marine plankton biomass, but also its diversity and community composition in poorly understood ways. Here, the authors model the spatial distribution of 860 marine plankton species from 10 functional groups and identify the future hotspots of climate change impacts under RCP8.5.

    • Fabio Benedetti
    • , Meike Vogt
    •  & Nicolas Gruber
  • Article
    | Open Access

    The Paleocene–Eocene boundary coincided with runaway global warming possibly analogous to future climate change, but the sources of greenhouse gasses have remained unresolved. Here, the authors reveal volcanism triggered initial warming, and subsequent carbon was released after crossing a tipping point.

    • Sev Kender
    • , Kara Bogus
    •  & Melanie J. Leng
  • Article
    | Open Access

    Anthropogenic extinctions are driving functional shifts in biological communities, but these changes might differ considerably among taxa and biogeographic regions. Here the authors show that projected losses of functional diversity among land and freshwater vertebrates are unevenly distributed across the world.

    • Aurele Toussaint
    • , Sébastien Brosse
    •  & Carlos P. Carmona
  • Article
    | Open Access

    Responses of ecosystem services to species losses are highly context-dependent. Here, the authors develop a model to identify general rules in the robustness of ecosystem service supply to species losses, and demonstrate its applicability using real-world ecosystem service networks.

    • Samuel R. P.-J. Ross
    • , Jean-François Arnoldi
    •  & Ian Donohue
  • Article
    | Open Access

    Nowhere is biomass burning more abundant than on the African continent, but the biogeochemical impacts on forests are poorly understood. Here the authors show that biomass burning leads to high phosphorus deposition in the Congo basin, which scales with forest age as a result of increasing canopy complexity.

    • Marijn Bauters
    • , Travis W. Drake
    •  & Pascal Boeckx
  • Article
    | Open Access

    Accurate seasonal forecasts of sea ice are highly valuable, particularly in the context of sea ice loss due to global warming. A new machine learning tool for sea ice forecasting offers a substantial increase in accuracy over current physics-based dynamical model predictions.

    • Tom R. Andersson
    • , J. Scott Hosking
    •  & Emily Shuckburgh
  • Article
    | Open Access

    It is still unclear when and by which route modern humans expanded out of Africa. Here, Beyer et al. use paleoclimate reconstructions and estimates of human precipitation requirements to evaluate the survivability of spatial and temporal migration corridors to Eurasia over the last 300,000 years.

    • Robert M. Beyer
    • , Mario Krapp
    •  & Andrea Manica
  • Article
    | Open Access

    Ambitious global targets exist for mangrove restoration. A meta-analysis reveals how mangrove restoration provides higher ecosystem benefits over unvegetated tidal flats, while generally lower than natural mangroves. Restoration outcomes, however, depend on restoration age, species and method.

    • Jie Su
    • , Daniel A. Friess
    •  & Alexandros Gasparatos
  • Article
    | Open Access

    Over the past century, the Western Antarctic Peninsula has experienced rapid warming and a substantial loss of sea ice with important implications for plankton biodiversity and carbon cycling. Using a 5-year DNA metabarcoding dataset, this study assesses how interannual variability in sea-ice conditions impacts biodiversity and biological carbon fluxes in this region.

    • Yajuan Lin
    • , Carly Moreno
    •  & Nicolas Cassar
  • Article
    | Open Access

    The motion of the ocean transports microorganisms, pollutants, and other particles, but these are challenging to track. Here the authors present a Lagrangian form of Betweenness Centrality which identifies bottlenecks in dynamical systems and fluid flows as well as an interpretation of diversity hotspots.

    • Enrico Ser-Giacomi
    • , Alberto Baudena
    •  & Emilio Hernández-García
  • Article
    | Open Access

    Episodic magmatism of the early Andes is the result of a complex interplay between mantle, crust, slab and sediment contributions that can be traced using zircon chemistry. An external (tectonic) model is argued for the episodic plutonism in this extensional continental arc.

    • José Joaquín Jara
    • , Fernando Barra
    •  & Diego Morata
  • Article
    | Open Access

    How climate change influences the lifecycle of stratospheric volcanic aerosols and the associated radiative forcing is unknown. Here, the authors present model experiments suggesting that climate change amplifies the forcing of large-magnitude tropical eruptions but reduces the forcing of moderate-magnitude tropical eruptions.

    • Thomas J. Aubry
    • , John Staunton-Sykes
    •  & Anja Schmidt
  • Article
    | Open Access

    The fraction of leaf nitrogen allocated to RuBisCO indicates differing nitrogen use strategies of plants and varies considerably. Here the authors show that this variation is largely driven by leaf thickness and phosphorus content with light intensity, atmospheric dryness and soil pH also having considerable influence.

    • Xiangzhong Luo
    • , Trevor F. Keenan
    •  & Yao Zhang
  • Article
    | Open Access

    The 2013 Castor seismic sequence, offshore Spain, is a rare example of seismicity induced by gas storage operations. Here we show that early seismicity marked the progressive failure of a fault in response to pore pressure diffusion, while later larger earthquakes resulted by the failure of loaded asperities.

    • Simone Cesca
    • , Daniel Stich
    •  & William L. Ellsworth
  • Article
    | Open Access

    We discover a pervasive subduction influence in the Arctic, Atlantic and Indian mantle, which is nearly absent in the Pacific mantle. Such a hemispheric-scale upper mantle heterogeneity reflects the control of a “subduction shield” that has surrounded the Pacific Ocean for 180 Myr.

    • A. Y. Yang
    • , C. H. Langmuir
    •  & Z. Chen
  • Article
    | Open Access

    Marine heat waves and cold spells threaten ocean ecosystems and are thought to be increasing with climate change. Here the author shows that MHW/MCS in the Tasman Sea co-occur with corresponding events in the Atlantic, Indian, and Pacific Oceans, and these southern hemisphere events are driven by stalling of a global wavenumber-4 atmospheric wave.

    • Stephen M. Chiswell
  • Article
    | Open Access

    N2 fixation was key to the expansion of life on Earth, but which organisms fixed N2 and if Mo-nitrogenase was functional in the low Mo early ocean is unknown. Here, the authors show that purple sulfur bacteria fix N2 using Mo-nitrogenase in a Proterozoic ocean analogue, despite low Mo conditions.

    • Miriam Philippi
    • , Katharina Kitzinger
    •  & Marcel M. M. Kuypers
  • 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