Cities will face increasing risk along with intensified climate shocks but can also act as key agents for mitigation and adaptation. We hope to see more research that could lead to enhanced climate action by providing comprehensive, equitable and practical solutions.

Urban areas are an important focus for effective climate action in the coming decade. This Perspective proposes transformational strategies to accelerate and upscale the impact of the planned Special Report on Climate Change and Cities in the IPCC seventh assessment cycle.

Urban development policies, designed to improve city resilience, could unintentionally increase the exposure to climate risk. This Comment discusses the impact of misaligned incentives, miscalculated benefits and costs, and overlooked behavioural responses on policy outcomes, as well as future directions.

C40 is a global network of mayors united in a commitment to climate change action. Since its inception in 2005, C40 has grown to include nearly 100 of the world’s cities, maintaining high standards that focus on inclusivity, collaboration and science-based approaches to combat climate change. We interviewed members of the C40 organization, including mayors of its member cities, to ask about the history, success and challenges of C40, and their plans for future action.

It is important to understand how much long-term sea-level rise is already committed due to historical and near-term emissions. Here the authors use a modelling framework to show how decisions on global emissions reductions in the coming decades alter multi-century sea-level rise projections.

The authors obtained large-volume individuals of diatom cultures under thermal stress. These polyploids (having more than two sets of chromosomes) are shown to rapidly adapt to high temperatures, highlighting polyploidization as a possible adaptive measure for diatoms under climate change.

Meat products represent a large share of the carbon footprints of cities, which are dependent on the characteristics of supply regions. With spatially explicit data, researchers show how the so-called carbon hoofprint varies between cities due to the different carbon intensities of producing regions.

The response of the phosphorus (P) cycle to permafrost thaw is unknown, but has implications for carbon dynamics. This study assesses changes in the P cycle upon abrupt thaw and shows accelerated soil P cycling and increased plant uptake, which may boost primary production and partially offset soil carbon loss.

The Southern Ocean carbon sink is predicted to decline under climate change. This study explores why this is yet to be seen in observations, finding that recent surface freshening increases stratification and traps the CO₂-rich water in the subsurface layer, which prevents atmospheric outgassing.

Standardized quantitative emissions benchmarking is essential for corporate climate accountability, yet recent literature has critiqued this approach. We argue for structured pluralism with budget compliance — balancing methodological flexibility while preserving the disciplining power of carbon budgets.

Causal approaches employed at the scale of commercial agriculture are required to build high-quality evidence that climate-smart agricultural interventions result in real emissions reductions and removals. Such project-scale empirical data are additionally required to demonstrate and advance the viability of process-based models and digital measurement, reporting and verification as tools to scale soil carbon accounting.

C40 is a global network of mayors united in a commitment to climate change action. Since its inception in 2005, C40 has grown to include nearly 100 of the world’s cities, maintaining high standards that focus on inclusivity, collaboration and science-based approaches to combat climate change. We interviewed members of the C40 organization, including mayors of its member cities, to ask about the history, success and challenges of C40, and their plans for future action.

Nearly one-third of the global shoreline is in the Arctic, a region undergoing some of the most rapid warming and substantial environmental transitions due to climate change. While Arctic research has largely focused on terrestrial and open-ocean systems, there is now an urgent need to focus on the unique challenges associated with changing coastal ecosystems.

Cities will face increasing risk along with intensified climate shocks but can also act as key agents for mitigation and adaptation. We hope to see more research that could lead to enhanced climate action by providing comprehensive, equitable and practical solutions.