Research articles

The Atlantic Meridional Overturning Circulation plays a central role in global climate through its transport of heat, carbon and fresh water. Its sensitivity to freshwater input change is shown to be muted when fluxes associated with the final Northern Hemisphere deglaciation are considered.

The authors define the global environmental niches of plankton from nano- (viruses) to meso-zooplankton (small metazoans) using metagenomic data. They assess reorganizations under climate change and the environmental drivers of change, with focus on the impacts on nitrogen and carbon fluxes.

Protecting the ocean from increasing threats requires the development of high-seas marine reserve networks. An approach that optimizes biodiversity, minimizes climate change exposure and reduces fisheries conflict enables low-regret climate-smart conservation areas to be identified.

Between 1955 and 2000 stratospheric ozone decreased and tropospheric ozone increased. Model analysis shows that these ozone changes each drove warming of the Southern Ocean through distinct mechanisms and together account for ~30% of the net subsurface Southern Ocean heat content increases over the same period, with the larger contribution from tropospheric increases.

Observations show that China is undergoing greater warming than the United States, yet climate models fail to capture the difference in warming trends. The difference in warming is a result of a stronger climate response to external forcing in China.

Permafrost peatlands are thawing, yet the timing and spatial dynamics of thaw are not well constrained. Under moderate and high warming scenarios, permafrost peatlands in Europe and Western Siberia will cross a tipping point where the climate becomes unsuitable, putting their carbon stores at risk.

Co-occurring hot and dry extremes are predicted to increase with global warming. Changes in precipitation will modulate the extent of these changes, highlighting the importance of understanding regional precipitation trends to prepare society and minimize impacts.

The current ambition for hydrofluorocarbon emissions reduction by the Kigali Amendment is not sufficient to meet the 1.5 °C Paris Agreement goal. The authors show that a more ambitious Kigali Amendment target could still help in achieving the Paris goal if more countries act early.

A large proportion of the population in developed countries will be of senior age in the years ahead. The carbon emissions of this group comprised an increasing share of the total emissions in developed countries in the past decade, with high expenditure on carbon-intensive products, and this trend will continue in the future.

Wheat genotypes with improved seedling emergence can be sown deeper, facilitating seedling survival under climate change. Crop modelling of these novel genotypes predicts yield increases of up to 20% relative to current genotypes in Australia, with potential for substantial gains in other regions globally.

The Amazon rainforest is increasingly under pressure from climate change and deforestation. The resilience of three-quarters of the forest, particularly in drier areas or close to human activity, has been decreasing since the 2000s, indicating that the system may be approaching a tipping point.

Determining the emergent climate change signals in the tropical Pacific—mean state and El Niño/Southern Oscillation (ENSO)—is crucial for climate action. Model simulations show that the mean sea surface temperature signal is already detectable, and that mean rainfall and ENSO-related signals could emerge around 2040.

Although public acceptance is essential for effective climate policies, the underlying drivers are still not well understood. Now, meta-analysis results show that perceived fairness and effectiveness have the strongest relationships with support for climate taxes and laws.

Despite overall warming, many regions in the Northern Hemisphere have been cooling in autumn. This cooling resulted in an increasing release of net CO₂ 2004–2018 as primary production decreased more than respiration in cooling and respiration increased more than production in warming areas.

Tropical forest restoration has the potential to remove large amounts of CO₂ from the atmosphere, but the climate mitigation potential could be threatened by climate change impacts. This study shows that carbon sequestered in restored forests is predominantly safe under a range of future scenarios.

Southwestern North America has been experiencing lower than average precipitation and higher temperatures since 2000. This emerging megadrought, spanning 2000–2021, has been the driest 22-year period since the year 800 and 19% of the drought severity in 2021 can be attributed to climate change.

Changes in precipitation remains an understudied factor that can impact leaf onset date (LOD) under climate change. The authors show that decreasing precipitation frequency has contributed to LOD advancement, and that incorporating precipitation data projects earlier LOD than currently predicted.

Coastal erosion in the Arctic is caused by permafrost thaw and wave abrasion enhanced by sea ice melt, both of which will increase under climate change. Projections of erosion rate across the Arctic indicate that mean erosion rates will rise beyond historical precedent over the twenty-first century.

Many heritage sites are threatened by rising sea levels under climate change as they lie within the coastal zone. A continental assessment of exposure of 284 African heritage sites shows that 20% of sites are currently at risk, which more than triples under moderate and high emission scenarios.

Glacial mass is dependent on the balance between melt and snow accumulation, which is impacted by rising Arctic temperatures. Glacier mass balances in Svalbard and northern Canada were asynchronous since the 1990s, related to changes in patterns of atmospheric heat advection.