New research identifies the key causes of changes affecting river deltas around the world and warns of an urgent need to tackle them through climate adaptation and policy.

Deltas are low-lying areas that form as rivers and empty their water and sediment into another body of water, such as an ocean, lake, or another river.

Some of the largest in the world, such as the Rhine, Mekong, Ganges-Brahmaputra-Meghna, and Nile, are threatened by climate change, facing rising sea levels and increasing frequency of extreme events.

With approximately 500 million people today living within or adjacent to delta systems, this is a major issue.​

Forest fires cause irreversible ecological and economic losses worldwide, often exacerbated by delayed or inefficient rescue efforts. A new study presents a groundbreaking data-driven framework to revolutionize aviation emergency networks. By integrating fire probability predictions with multi-objective optimization, the research enables faster, cost-effective rescue planning tailored to real-world fire risks. Tested in China’s Hainan Province, the model reduces response times while balancing ecological and operational costs—offering a scalable solution for global forest protection.

A new study challenges the long-debated theory that a massive, kilometre-thick ice shelf once covered the entire Arctic Ocean. By analysing ocean sediments and running advanced climate models, researchers found that seasonal sea ice—rather than a continuous ice shelf—has been the dominant feature of the Arctic for the past 750,000 years. This discovery gives insights crucial for our understanding of how the Arctic has responded to climate change in the past—and how it might behave in the future.

In a study published in National Science Review, researchers present multiple lines of observational and modeling evidence for a ~4% decline in global atmospheric oxidation capacity in 2020, reflected by a drop in hydroxyl radical (OH) concentrations. Using satellite-based carbon monoxide data, as well as methane and methyl chloroform observations, the study reveals that this OH reduction occurred in both hemispheres—approximately 2.4% in the Northern Hemisphere and 5.7% in the Southern Hemisphere—driven by distinct mechanisms. In the Northern Hemisphere, reduced NO_x emissions due to COVID-19 lockdowns led to lower OH and tropospheric ozone levels, while in the Southern Hemisphere, massive emissions of reactive carbon from unprecedented Australian wildfires caused OH depletion but tropospheric ozone increases. This contrast in tropospheric ozone anomalies is further corroborated by satellite data. The findings help explain one of the record-breaking rises in atmospheric methane in 2020 and underscore the critical role of both natural and anthropogenic factors in shaping Earth’s atmospheric chemistry and global methane budget.

Trees help clean the air in cities but they also contribute to smog formation. A recent study conducted at Beijing Forestry University analyzed six major urban tree species for carbon storage and biogenic volatile organic compound (BVOC) emissions using field surveys and satellite data. The findings revealed two tree species: Robinia pseudoacacia and Betula platyphylla, as the ideal for maximizing carbon capture while minimizing harmful emissions—guiding smarter urban forest planning in China.

In a paper published in National Science Review, a research team led by Chinese scientists quantifies changes in dissolved carbon storage within China's lakes and reservoirs alongside dissolved carbon fluxes in rivers over the past three decades, systematically revealing how climate change, anthropogenic disturbances, and water chemistry factors collectively drive the dynamics of dissolved carbon in inland waters. The study finds that dissolved carbon storage across China's inland waters has increased significantly during this period, with riverine carbon fluxes primarily driven by climate and human factors, while lake and reservoir carbon storage is dominated by water chemistry controls.

Researchers from the University of Copenhagen have gained unique insight into the mechanisms behind the collapse of Antarctic ice shelves, which are crucial for sea level rise in the Northern Hemisphere. The discovery of old aerial photos has provided an unparalleled dataset that can improve predictions of sea level rise and how we should prioritise coastal protection and other forms of climate adaptation.