Articles in 2020

Warming is increasing glacial lakes, and scaling relations show a 48% increase in volume for 1990 to 2018. All measures—area, volume, number—increased, providing water storage but also representing a potential hazard with the risk of outburst floods.

Aerosol transport from South Asia to the Tibetan Plateau (TP) peaks in the pre-monsoon period, but the controlling dynamics remain unclear. Observational analysis shows that low February Arctic sea ice boosts the Asian subtropical jet in April, which can loft aerosols over the Himalayas onto the TP.

In this interconnected world, many of us would regularly jump on a plane, or train, for a weekend away, or into a car to pop to the shops or to visit family and friends. But the way we travel, day-to-day and on longer trips, will need to change if mitigation targets, including net-zero aspirations, are to be met.

We need a modern-day Marshall Plan to build climate resilience in the developing world. It is doable if, for each dollar spent reaching net zero, we spend an additional 25 cents on building resilience.

A new star has exploded back onto the climate scene: hydrogen. It offers possibilities to move away from fossil fuels, but it brings its own challenges.

Theory and observation suggest that populations of long-lived organisms fare worse than short-lived counterparts when submitted to increased mortality. Now, research shows that longevity affords the prospect of reducing mortality by breeding less under stress.

Gaps in geographic coverage of species abundance data, especially in the tropics, make determining species’ responses to climate change difficult. Modelling a dataset on global waterbird abundance shows abundance declines in the tropics and increases at higher latitudes when temperatures increase.

As road transport emissions are set to grow, stronger policy mixes are needed to reach mitigation goals. This Perspective considers the evidence for several policy types—strong regulation, pricing and reduced travel—and the best combination to reduce emissions for passenger and freight vehicles.

Cities have an important role in climate mitigation. Textual analysis techniques and regression modelling show the progress made by over 1,000 cities reporting in the European Covenant of Mayors initiative, active in climate action at the urban level.

Negative emissions technologies are a cornerstone of many mitigation scenarios that limit global warming under 2 °C. Depending on the conditions, bioenergy with carbon capture and storage can provide negative emissions but requires large amounts of land and should be deployed early and with limits.

Climate change impacts on population dynamics will depend on species’ life history strategies. In contrast to short-lived species, longer-lived tropical songbirds reduced reproduction during drought, leading to higher survival and mitigating the effect on long-term population growth.

Negative emissions technologies are essential in scenarios for meeting Paris climate targets. Modelling results show that direct air capture could play an important role with less demand for land yet high energy and water use compared with BECCS and afforestation.

Gravity-based estimates of mass change have been extended by the recently launched GRACE Follow-On Satellites. The satellite record, combined with regional climate models, reveals that the Greenland Ice Sheet had lower mass loss in 2017–2018, only to return to a record-breaking mass loss in the summer of 2019.

The response of coastal groundwater to sea-level rise is largely unknown. Groundwater modelling along the California coast — accounting for complex topography and its interaction with rivers, streams and tributaries — shows that the area at risk from rising groundwater tables extends beyond that inundated by sea-level rise alone.

Reforestation has been recently identified as a promising climate mitigation option. In Southeast Asia, 120 million ha of land are biophysically suitable for reforestation. However, financial, land-use and operational factors constrain mitigation potential to a fraction of its total possible value.

Climate change is driving changes in the species composition of plant communities. Analyses of the collection records of thousands of New World plant species reveal widespread increases in the relative abundances of heat-loving species but less consistent responses to changes in precipitation.