• Commentary |

    Quality requirements for water differ by intended use. Sustainable management of water resources for different uses will not only need to account for demand in water quantity, but also for water temperature and salinity, nutrient levels and other pollutants.

    • Michelle T.H. van Vliet
    • , Martina Flörke
    •  & Yoshihide Wada
  • Commentary |

    Developments in attribution science are improving our ability to detect human influence on extreme weather events. By implication, the legal duties of government, business and others to manage foreseeable harms are broadening, and may lead to more climate change litigation.

    • Sophie Marjanac
    • , Lindene Patton
    •  & James Thornton
  • Commentary |

    Reconstructions of Earth's past are much more than benchmarks for climate models. They also help us comprehend risk by providing concrete narratives for diverse climates.

    • Richard D. Pancost
  • Commentary |

    The terrestrial water cycle is often assessed annually at catchment scale. But water stored in catchments is poorly mixed, and at timescales often well beyond the calculation of annual water balance.

    • Jeffrey J. McDonnell
  • Commentary |

    Mining the deep seabed is fraught with challenges. Untapped mineral potential under the shallow, more accessible continental shelf could add a new dimension to offshore mining and help meet future mineral demand.

    • Mark Hannington
    • , Sven Petersen
    •  & Anna Krätschell
  • Commentary |

    The Intergovernmental Panel on Climate Change is preparing a report on keeping global warming below 1.5 °C. How the panel chooses to deal with the option of solar geoengineering will test the integrity of scientific climate policy advice.

    • Andy Parker
    •  & Oliver Geden
  • Commentary |

    To keep global warming below 2 °C, countries need long-term strategies for low-emission development. Without these, immediate emissions reductions may lock-in high-emitting infrastructure, hamper collaboration and make climate goals unachievable.

    • Jeffrey D. Sachs
    • , Guido Schmidt-Traub
    •  & Jim Williams
  • Commentary |

    Slowing GDP growth, a structural shift away from heavy industry, and more proactive policies on air pollution and clean energy have caused China's coal use to peak. It seems that economic growth has decoupled from growth in coal consumption.

    • Ye Qi
    • , Nicholas Stern
    • , Tong Wu
    • , Jiaqi Lu
    •  & Fergus Green
  • Commentary |

    After more than a decade exploring Saturn and its moons, the Cassini mission is in its closing act. Cassini's last year is an encore performance stuffed with science, including a final plunge into Saturn's atmosphere.

    • Scott G. Edgington
    •  & Linda J. Spilker
  • Commentary |

    The New Horizons mission has revealed Pluto and its moon Charon to be geologically active worlds. The familiar, yet exotic, landforms suggest that geologic processes operate similarly across the Solar System, even in its cold outer reaches.

    • Paul Schenk
    •  & Francis Nimmo
  • Commentary |

    The Paris Agreement introduced three mitigation targets. In the future, the main focus should not be on temperature targets such as 2 or 1.5 °C, but on the target with the greatest potential to effectively guide policy: net zero emissions.

    • Oliver Geden
  • Commentary |

    The need to mitigate climate change opens up a key role for cities. Bristol's year as a Green Capital led to great strides forward, but it also revealed that a creative and determined partnership across cultural divides will be necessary.

    • Richard D. Pancost
  • Commentary |

    The adoption of the Paris Agreement is a historic milestone for the global response to the threat of climate change. Scientists are now being challenged to investigate a 1.5 °C world — which will require an accelerated effort from the geoscience community.

    • Joeri Rogelj
    •  & Reto Knutti
  • Commentary |

    Drought management is inefficient because feedbacks between drought and people are not fully understood. In this human-influenced era, we need to rethink the concept of drought to include the human role in mitigating and enhancing drought.

    • Anne F. Van Loon
    • , Tom Gleeson
    • , Julian Clark
    • , Albert I. J. M. Van Dijk
    • , Kerstin Stahl
    • , Jamie Hannaford
    • , Giuliano Di Baldassarre
    • , Adriaan J. Teuling
    • , Lena M. Tallaksen
    • , Remko Uijlenhoet
    • , David M. Hannah
    • , Justin Sheffield
    • , Mark Svoboda
    • , Boud Verbeiren
    • , Thorsten Wagener
    • , Sally Rangecroft
    • , Niko Wanders
    •  & Henny A. J. Van Lanen
  • Commentary |

    In the absence of an enforceable set of commitments to reduce greenhouse gas emissions, concerned citizens may want to supplement international agreements on climate change. We suggest that litigation could have an important role to play.

    • James Thornton
    •  & Howard Covington
  • Commentary |

    Some climate change impacts rise fast with little warming, and then taper off. To avoid diminishing incentives to reduce emissions and inadvertently slipping into a lower-welfare world, mitigation policy needs to be ambitious early on.

    • Katharine L. Ricke
    • , Juan B. Moreno-Cruz
    • , Jacob Schewe
    • , Anders Levermann
    •  & Ken Caldeira
  • Commentary |

    Multi-actor integrated assessment models based on well-being concepts beyond GDP could support policymakers by highlighting the interrelation of climate change mitigation and other important societal problems.

    • Klaus Hasselmann
    • , Roger Cremades
    • , Tatiana Filatova
    • , Richard Hewitt
    • , Carlo Jaeger
    • , Dmitry Kovalevsky
    • , Alexey Voinov
    •  & Nick Winder
  • Commentary |

    Despite legislation to protect natural sites, rock outcrops are being damaged in the name of science. Scientists, funders and publishers must push forward a stronger code of ethics.

    • Rob Butler
  • Commentary |

    Delivery of palatable 2 °C mitigation scenarios depends on speculative negative emissions or changing the past. Scientists must make their assumptions transparent and defensible, however politically uncomfortable the conclusions.

    • Kevin Anderson
  • Commentary |

    The United Nations' Sustainable Development Goals emphasize the importance of evidence-based decision-making. This is a clarion call for Earth scientists to contribute directly to the health, prosperity and well-being of all people.

    • Jane Lubchenco
    • , Allison K. Barner
    • , Elizabeth B. Cerny-Chipman
    •  & Jessica N. Reimer
  • Commentary |

    A truly global science community for the next generation of researchers will be essential if we are to tackle Earth system sustainability. Top-down support from funders should meet bottom-up initiatives — at a pace fast enough to meet that of early-career progress.

    • Florian Rauser
    • , Vera Schemann
    •  & Sebastian Sonntag
  • Commentary |

    Since 1999, China's Grain for Green project has greatly increased the vegetation cover on the Loess Plateau. Now that erosion levels have returned to historic values, vegetation should be maintained but not expanded further as planned.

    • Yiping Chen
    • , Kaibo Wang
    • , Yishan Lin
    • , Weiyu Shi
    • , Yi Song
    •  & Xinhua He
  • Commentary |

    The geosciences benefit from diverse student perspectives and backgrounds, but the field-based learning requirements pose barriers to students with disabilities. If carefully designed, fieldwork can be made accessible while still meeting expectations of academic rigour.

    • Brett Gilley
    • , Chris Atchison
    • , Anthony Feig
    •  & Alison Stokes
  • Commentary |

    Increased efforts in recruiting minority students have not proven to be enough to address the lack of diversity in the geosciences. A collaborative mentoring culture is needed to permanently change the make-up of our field.

    • Rebecca Haacker
  • Commentary |

    The history of attempts to spread scientific know-how beyond western centres of excellence is littered with failures. Capacity building needs long-term commitment, a critical mass of trainees, and a supportive home environment.

    • Bruce Hewitson
  • Commentary |

    Natural landscapes are shaped by frequent moderate-sized events, except for the rare catastrophe. Human modifications to the Earth's surface are, compared with natural processes, increasingly catastrophic.

    • Richard Guthrie
  • Commentary |

    The 1815 eruption of Tambora caused an unusually cold summer in much of Europe in 1816. The extreme weather led to poor harvests and malnutrition, but also demonstrated the capability of humans to adapt and help others in worse conditions.

    • J. Luterbacher
    •  & C. Pfister
  • Commentary |

    The impact of a volcanic eruption depends on more than just its size. We need more interdisciplinary research to understand the global societal consequences of past and future volcanic eruptions.

    • Clive Oppenheimer
  • Commentary |

    200 years after the eruption of Mount Tambora, the eruption volume remains poorly known, as is true for other volcanic eruptions over past millennia. We need better records of size and occurrence if we are to predict future large eruptions more accurately.

    • Stephen Self
    •  & Ralf Gertisser
  • Commentary |

    The status of sea floors is an important part of healthy marine ecosystems and intact coastlines. We need laws and a sea-floor management regime to make the exploitation of marine resources sustainable.

    • Till Markus
    • , Katrin Huhn
    •  & Kai Bischof
  • Commentary |

    Ore bodies buried deep in Earth's crust could meet increasing global demands for metals, but mining them would be costly and could damage the environment. Reinventing an ancient technology for bioleaching metals could provide a solution.

    • D. Barrie Johnson
  • Commentary |

    Today, the ratio of carbon to nitrogen and phosphorus in marine organic matter is relatively constant. But this ratio probably varied during the Earth's history as a consequence of changes in the phytoplankton community and ocean oxygen levels.

    • Noah J. Planavsky
  • Commentary |

    The ratio of nitrogen to phosphorus in organic matter is close to that in seawater, a relationship maintained through a set of biological feedbacks. The rapid delivery of nutrients from human activities may test the efficacy of these processes.

    • Nicolas Gruber
    •  & Curtis A. Deutsch
  • Commentary |

    Open source software is often seen as a path to reproducibility in computational science. In practice there are many obstacles, even when the code is freely available, but open source policies should at least lead to better quality code.

    • Steve M. Easterbrook
  • Commentary |

    Journals and funders increasingly require public archiving of the data that support publications. We argue that this mandate is necessary, but not sufficient: more incentives for data sharing are needed.

    • Jens Kattge
    • , Sandra Díaz
    •  & Christian Wirth
  • Commentary |

    The emerging scientific focus on cumulative carbon emissions may make climate negotiations harder. But, it serves to clarify the scale and scope of climate mitigation needed to meet potential temperature targets.

    • David J. Frame
    • , Adrian H. Macey
    •  & Myles R. Allen
  • Commentary |

    Water availability and use are inherently regional concerns. However, a global-scale approach to evaluating strategies to reduce water stress can help maximize mitigation.

    • Yoshihide Wada
    • , Tom Gleeson
    •  & Laurent Esnault
  • Commentary |

    Expansion of geothermal energy use across the globe is restricted by out-of-date prejudices. It is time for geothermal exploration to be extended to a broader range of environments and rejuvenated with the latest insights from relevant geoscience disciplines.

    • Paul L. Younger
  • Commentary |

    As well as being a milestone in technology, the Chang'e lunar exploration programme establishes China as a contributor to space science. With much still to learn about the Moon, fieldwork beyond Earth's orbit must be an international effort.

    • Long Xiao
  • Commentary |

    Biochar has been heralded as a solution to a number of agricultural and environmental ills. To get the most benefit from its application, environmental and social circumstances should both be considered.

    • S. Abiven
    • , M. W. I. Schmidt
    •  & J. Lehmann
  • Commentary |

    Livestock production accounts for a significant fraction of global anthropogenic greenhouse gas emissions. Progress in mitigating the adverse environmental impacts of this industry can be improved by shifting research emphases and fostering communication between researchers and ranchers.

    • Joseph M. Craine
  • Commentary |

    Large tracts of agricultural land are being bought up by external investors. Turning the land into a commodity can have detrimental effects, for generations to come, on the local communities that sell or lease the land.

    • Paolo D'Odorico
    •  & Maria Cristina Rulli
  • Commentary |

    Climate models projected stronger warming over the past 15 years than has been seen in observations. Conspiring factors of errors in volcanic and solar inputs, representations of aerosols, and El Niño evolution, may explain most of the discrepancy.

    • Gavin A. Schmidt
    • , Drew T. Shindell
    •  & Kostas Tsigaridis
  • Commentary |

    Decadal climate variability has long received limited attention. With the slow-down in surface warming since the late 1990s, the decadal scale has rightly become a focus of attention: for assessing climate change and its impacts, it is of critical importance.

    • Martin Visbeck
  • Commentary |

    Scientific climate information can save lives and livelihoods, yet its application is not always straightforward. Much of the available information does not describe the risk of threshold events, and misunderstandings can leave society less resilient to climate shocks.

    • Erin Coughlan de Perez
    • , Fleur Monasso
    • , Maarten van Aalst
    •  & Pablo Suarez
  • Commentary |

    Renewable energy requires infrastructures built with metals whose extraction requires more and more energy. More mining is unavoidable, but increased recycling, substitution and careful design of new high-tech devices will help meet the growing demand.

    • Olivier Vidal
    • , Bruno Goffé
    •  & Nicholas Arndt
  • Commentary |

    Access to metals and minerals is restricted mostly by geopolitical constraints, and not by a shortage of mineable deposits. In the face of rising demand, a full inventory of these commodities — in the Earth's crust as well as in recyclable waste — is urgently required.

    • Richard Herrington
  • Commentary |

    Mineable phosphorus reserves are confined to a handful of countries. Reductions in wastage could free up this resource for low-income, food-deficient countries.

    • Michael Obersteiner
    • , Josep Peñuelas
    • , Philippe Ciais
    • , Marijn van der Velde
    •  & Ivan A. Janssens
  • Commentary |

    Particles of organic matter in the ocean host diverse communities of microorganisms. These particles may serve as hotspots of bacterial gene exchange, creating opportunities for microbial evolution.

    • Frank J. Stewart
  • Commentary |

    Geological and biological processes have eliminated all but the faintest traces of our earliest ancestors on Earth. To understand the origin of life, we must investigate other planets — but we can find what we seek only if we do not contaminate them with Earth life first.

    • Catharine A. Conley
    •  & John D. Rummel