Border carbon adjustments are appraised as a measure to address carbon leakage and competitiveness concerns. This Review Article discusses the possible impacts, as well as practical challenges for implementation.

Carbon tax rebate programmes have received increasing interest with the potential to raise public support for carbon pricing. However, results of online surveys based on existing real-world policies demonstrate such programmes have had limited political impacts to date.

We find that the public prefers the costs of climate action to be constant over time, irrespective of whether average costs are low or high. Policymakers interested in combating global warming should therefore introduce policies that initially rely on stable cost schedules instead of the widely discussed alternative of ramping up costs over time.

Climate policy analyses often ignore the possibility of progressive redistribution of carbon tax revenues and assume that mitigation cost will burden the poor in the short term. Integrated Assessment Model (IAM) estimation suggests such redistribution could reduce inequality, alleviate poverty and increase well-being globally.

The co-occurrence of drought across different regions will have far-reaching effects on global agriculture and food supply. Model projections show an increased likelihood of these compound droughts under a high-emissions scenario, with a ninefold increase of farm land and population exposure.

Changes to tropical cyclones will increase the risk to US coastlines. Under a high-emissions scenario, the joint hazards of extreme rainfall and storm tides increase, with the largest contribution being from increasing cyclone intensity and decreasing translation speed, rather than sea-level rise.

The authors use central European observations of leaf unfolding date (LUD) for six tree species. They demonstrate antagonistic and heterogenous effects of winter chilling and spring thermal accumulation on leaf phenology, with the latter having greater explanation (61% versus 39%) for LUD advancement.

Understanding the impact of future marine heatwaves on coastal ecosystems, which account for most of global fishery catches, is limited due to low-resolution models. Use of high-resolution models shows increases in intensity, and the number of days, of marine heatwaves, endangering resident species.

The authors link the effects of pCO₂ on marine invertebrates to the localized pCO₂ conditions of their coastal habitats. They show that responses depend on the deviation from the locally experienced upper pCO₂ level, highlighting the importance of small-scale variability and adaptation.

Sea surface temperature variability of the equatorial Pacific Ocean dictates the strength of El Niño–Southern Oscillation events. CMIP6 models under four IPCC emission scenarios show increased variability in the 21st century from the 20th century.

In the context of rising climate uncertainties, there is an urgent need for greater convergence between water and climate change policies. To improve adaptation outcomes, a reorientation towards justice and rights-based frameworks is required.

Climate change action is moving forward, with the outcomes from COP26 setting the agenda for governments to commit to. Actors in the private sector are also setting out commitments, and climate action looks to be gaining momentum across society and around the globe.