The northward shift and rapid displacement of the Gulf Stream provide an indirect early warning of Atlantic Meridional Overturning Circulation weakening and collapse, revealed by both high-resolution ocean simulations and historical observations.

Meltwater generated within the Dotson Ice Shelf cavity supplies little dissolved iron. Most meltwater-derived iron found in water flowing out of the cavity comes from subglacial discharge, based on iron concentrations and dissolved iron isotope ratios.

The reduction of sea ice off the Marie Byrd Land coast in 2022 and 2024 resulted in serious impact on the moulting of emperor penguins, as revealed by a satellite imagery study in West Antarctica during 2019 to 2025.

Climate change is increasing the risk of ice-rock avalanches in the Himalaya while preparedness and recognition remain limited, according to a reassessment of the 2021 Chamoli disaster, lessons from the Blatten near-miss, and analysis of institutional gaps that motivate an anticipatory hazard governance framework.

Marine oxygen loss intensified millions of years before the end-Triassic mass extinction, coinciding with biodiversity declines, according to an analysis using sedimentary iron speciation and nitrogen isotopes to reconstruct water-column redox changes.

IPCC emission factors potentially overestimate carbon dioxide emissions from cool temperate and boreal croplands on organic soils in Norway, according to calibrated soil-plant-atmosphere system modeling.

Cyclonic and anticyclonic atmospheric synoptic forcings produce pronounced vertical structure in upper-ocean temperature anomalies in the eastern Eurasian Arctic, with their magnitude and timing shaped by the seasonal evolution of sea ice and stratification, as shown by experiments using a high-resolution ocean-ice coupled model.

Population density and agricultural activity intensify fractional floating algal cover in 71% global lakes, whereas temperature and wind regulate the bloom phenology, according to an analysis of Moderate Resolution Imaging Spectroradiometer (MODIS) data across 4085 global lakes for two decades.

Natural forest conversion reduces soil respiration by 7% through strong declines in autotrophic respiration and raises temperature sensitivity after conversion to agriculture and grassland, with both responses returning to forest levels within 30 years, based on 452 paired observations.

Sub-Saharan Africa and Indus River Valley are two hotpots of the occurrence of compound heat-pollution events in recent decades, though with different circulation backgrounds, revealed by fine scale global assessment.

The Earth’s climate is regulated and stabilised by interconnected ecosystem processes. This Comment argues that following on from COP30, nature-based indicators should be integrated into formal climate policy processes—such as the Global Stocktake and Nationally Determined Contributions—to strengthen the coherence between climate governance and Earth System stability.

Adoption of the International Maritime Organisation’s Net Zero Framework was postponed by one year, to October 2026. This Comment argues that this time window must be used to address four outstanding challenges, and that success can turn the maritime sector into a model for achieving the Paris climate goals.

Fluctuations in the Earth’s magnetic field across time may have had wide-ranging impacts on ecosystems. Dr Tarduno and colleagues used paleomagnetic data from silicate crystals to examine the Ediacaran period. Crystal data indicated that Earth’s magnetic field had decreased in intensity, becoming 10 to 30 times weaker than the present day. This profound and unprecedented reduction in magnetic field intensity aligned with a diversification in macroscopic animals, suggesting that changes in Earth’s magnetic shielding contributed to Earth’s oxygenation and therefore supported faunal diversification.

Freshwater ecosystems produce methane, a potent greenhouse gas, and ponds on agricultural land are particularly strong emitters. Dr Malerba and colleagues used maps of agricultural ponds and compiled data on their emissions to produce assessments of methane emissions from agricultural ponds for both the USA and Australia. They found emissions twice as high as were initially being accounted for under national inventories, highlighting the need to account for this source in national inventories.

Vehicle emission standards have long been based on laboratory tests. This comment argues that policymakers now can and should regulate vehicles also based on real-world data. Europe’s performance-based regulation of plug-in hybrid vehicles can help develop more adaptive and evidence-based policies for transportation, energy, and environment.

On 28 May 2025, twenty million cubic metres of rock and ice buried the medieval village of Blatten and nearby settlements in the Swiss Lötschen valley. In the wake of the warmest decade since at least 742 CE, the disaster underlines the impact of climate warming on people and heritage.