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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.