Volume 10 Issue 10, October 2020

Observed ice-sheet losses track the upper range of the IPCC Fifth Assessment Report sea-level predictions, recently driven by ice dynamics in Antarctica and surface melting in Greenland. Ice-sheet models must account for short-term variability in the atmosphere, oceans and climate to accurately predict sea-level rise.

The impacts of climate change on people and societies are varied and nuanced, making it difficult to encapsulate in an image. Photographs of people can, however, create an emotional connection to what may otherwise be viewed as a natural problem.

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.

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.

Ongoing Arctic changes are impacting phytoplankton. This Review considers recent primary productivity trends and the environmental drivers, as well as how these are changing, that drive phytoplankton diversity in the region.

Using a meta-analysis approach, the authors find robust evidence that environmental factors play a role in explaining migration patterns across countries and over time, but the size of the effects depend on the economic and sociopolitical context, and the environmental factors considered.

Reduced GHG and air pollutant emissions during the COVID-19 lockdowns resulted in declines in NO_x emissions of up to 30%, causing short-term cooling, while ~20% SO₂ emissions decline countered this for overall minimal temperature effect.

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.

Arctic climate in the Last Interglacial (LIG)—a warm period 130,000–116,000 years ago—is poorly simulated by modern climate models. A model with improved sea-ice melt-pond physics reproduces LIG Arctic temperatures, suggests an ice-free Arctic during this period and predicts the same by 2035.

Climate warming over Canada drives glacier retreat and threatens water resources in regions that rely on downstream meltwater. Streamflow and climate data are combined with a municipal water source database to identify Alberta communities whose water supply would be most impacted by glacier retreat.

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.

Sea-level rise raises water tables, causing flooding from below and saltwater intrusion. A modelling study predicts that coastal California groundwater flooding will expand 50–130 m inland with 1 m of sea-level rise, with areal flooding extent strongly dependent on topography and drainage capacity.

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.

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.

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.