Comment

It is commonly thought that old groundwater cannot be pumped sustainably, and that recently recharged groundwater is inherently sustainable. We argue that both old and young groundwaters can be used in physically sustainable or unsustainable ways.

The InSight mission on Mars is currently providing us with the first seismic data from a planetary body other than our own Earth since the 1970s. Past efforts will inform this next chapter in planetary seismology.

Geoscientists in the United States are predominantly White. Progress towards diversification can only come with a concerted shift in mindsets and a deeper understanding of the complexities of race.

Scientists and policymakers must acknowledge that carbon dioxide removal can be small in scale and still be relevant for climate policy, that it will primarily emerge ‘bottom up’, and that different methods have different governance needs.

Governments disagree even on the current state of climate change engineering governance, as became clear at the 2019 United Nations Environment Assembly negotiations. They must develop mechanisms to provide policy-relevant knowledge, clarify uncertainties and head off potential distributional impacts.

The climate of South and East Asia is affected by anthropogenic aerosols, but the magnitude of the aerosol imprint is not well known. As regional emissions are rapidly changing, potential related climate risks must be quantified.

Social media is increasingly being used to share near-real-time analysis of emergent and sometimes hazardous geological events. Such open discussion can drive new research directions and collaborations for geoscientists.

Field work is an important and valued part of geoscience research, but can also serve as a source of stress. Careful planning can help support the mental health and wellness of participants at all career stages.

January 2018 was an unusually warm and wet month across the Western Alps, with widespread landslides at low elevations and massive snowfall higher up. This extreme month yields lessons for how mountain communities can prepare for a warmer future.

The remaining carbon budget consistent with limiting warming to 1.5 °C allows 20 more years of current emissions according to one study, but is already exhausted according to another. Both are defensible. We need to move on from a unique carbon budget, and face the nuances.

Upward estimates for carbon budgets are unlikely to lead to action-focused climate policy. Climate researchers need to understand processes and incentives in policymaking and politics to communicate effectively.

Ethnic and racial diversity are extremely low among United States citizens and permanent residents who earned doctorates in earth, atmospheric and ocean sciences. Worse, there has been little to no improvement over the past four decades.

The exploration of ocean worlds in the outer Solar System offers the opportunity to search for an independent origin of life, and also to advance our capabilities for exploring and understanding life in Earth’s oceans.

Making sense of exoplanet observations requires better understanding of terrestrial atmospheres in our solar system, especially for Venus. We need to not just intermittently explore, but continuously monitor these atmospheres — like we do for Earth.

Temperature overshoot scenarios that make the 1.5 °C climate target feasible could turn into sources of political flexibility. Climate scientists must provide clear constraints on overshoot magnitude, duration and timing, to ensure accountability.