United Nations Environment Programme

Rivers are key pathways for transporting plastic pollution to the ocean, yet global estimates of riverine plastic export remain highly uncertain due to catchment diversity and the complexity of transport processes. To better understand dynamics at the river–ocean interface, we analyzed a comparative dataset from three rivers in the Caribbean, Southern Africa, and Southeast Asia, each characterized by distinct hydrometeorological and tidal regimes. We tracked 196 GPS drifters and monitored surface transport using forty-one cameras deployed across six river locations over multiple seasons. These observations informed simulations of three years of plastic transport (2020–2022). We find that rivers flush 50% of their floating plastics downstream within only 7–12% of the time. Annual average mass fluxes for the three rivers were 34–98% lower than previously reported by global models. Our results highlight that rivers act as long-term sinks for plastic pollution, and that estuarine transport is more limited than often assumed. This study provides critical observational and modelling insights to refine river‑to‑ocean plastic flux estimates and emphasizes the heterogeneity of emission dynamics across diverse river systems.

Plastics are deeply embedded in modern life, but their degradation releases micro- and nanoplastics (MNPs) into ecosystems. These persistent particles are found everywhere, from oceans to the human body, and raise growing concerns about environmental and human health, biodiversity, and sustainability implications. Despite increasing awareness, effective responses to MNP pollution remain limited by unresolved challenges in scientific monitoring, policymaking, and public engagement. Addressing these challenges, the summer school on "Microplastics: From Environmental Impact to Policy, Innovation, and Public Awareness" held in June 2025 in Geneva, Switzerland, exemplifies an innovative educational model. The program was multi- and interdisciplinary, action-oriented, internationally collaborative, and rooted in local contexts. Focusing on microplastic pollution in aquatic environments, it brought together participants from 15 countries to explore the nexus of science, policy, governance, innovation, and public engagement. This contribution reflects the summer school's design and outcomes, highlighting its promise as a model for advancing next-generation environmental education as well as discussing some of the key challenges.

Abstract Between 28 October and 4 November 2024, Spain experienced an extreme precipitation event with new national records for subdaily precipitation intensity. The event, driven by a cutoff low and moist influx from a warm Mediterranean Sea, triggered devastating floods and severe socioeconomic impacts, leading to 237 fatalities and EUR 17 billion in estimated economic losses. In this study, we conduct a comprehensive attribution analysis that integrates complementary methods with varying levels of conditionality to assess the influence of climate change on this extreme event. They include unconditional probabilistic approaches, flow-conditioned analogs, and highly conditioned storylines. Unconditional probabilistic methods found no discernible anthropogenic influence on the probability and magnitude of such events at local and regional scales, aligning with historical extreme precipitation trends in Spain. In contrast, dynamical conditioning using low pressure systems similar to the observed one revealed detectable climate change–related increases in precipitation, partially mediated by warm western Mediterranean sea surface temperatures. Highly conditioned storylines uncovered robust signals in precipitation and the thermodynamic drivers of the event, including human-induced moistening, but weak or nonrobust responses in dynamical aspects. These findings highlight the complexity of attributing convective extremes and the intricate interplay between dynamical and thermodynamic factors. The study underscores the complementarity, as opposed to the conflict, of different attribution approaches and illustrates the importance of combining attribution methods with varying levels of conditionality to provide a comprehensive understanding of climate change’s role in extreme events. Significance Statement The extreme rainfall of October 2024 in Spain caused hundreds of fatalities and raised pressing questions about the role of climate change. We use observations, reanalysis, and data-driven weather forecasts to address changes in the frequency of threshold-crossing events, the severity of similar events, and the synoptic drivers of the actual event. These attribution questions yield different but reconcilable answers, with consistent climate change signals emerging when the atmospheric conditions of the event are considered. Our results highlight the importance of addressing the full spectrum of attribution questions and provide guidance for collecting multiple evidences through a comprehensive integration of climate-to-weather approaches with varying degree of conditionality on the observed event.

China’s crop production evolution has significantly reshaped spatial and temporal patterns of agricultural carbon emissions. However, a comprehensive understanding of the underlying driving mechanism of agricultural carbon emissions remains limited, particularly across different regions and crop types. This study integrates micro and macro-level data, spanning 14 crop types, 13 emission sources, and 31 provinces, and constructs a full-lifecycle panel database from 2001 to 2021. Using Moran’s I global index analysis and spatial autoregressive models, we comprehensively assessed the impacts and spatial spillover effects of economic features, agricultural production characteristics, supporting policies, and climate conditions on carbon emissions from crop production. Our analysis reveals a nationwide increase in crop production carbon emissions, accompanied by widening disparities across regions and crop types. Additionally, it demonstrates that a 1% increase in urbanization, precipitation, and temperature is associated with a 0.02%, 0.26%, and 0.52% decrease in total agricultural carbon emissions, respectively. Moreover, contrary to previous findings suggesting that economic development exacerbates agricultural emissions, we observed that in major grain-producing regions, a 1% decrease in per capita GDP is linked to a 0.32% increase in carbon emissions, along with a 0.23% increase in emission intensity per unit area and 0.22% increase in per unit yield, which implies that these underdeveloped areas rely more on agricultural production and need more government support, putting more pressure on the environment. This study highlights the importance of integrating agricultural and environmental policies to address economic development, regional disparities, sustainable crop production, and carbon emission management.

Antimicrobial resistance (AMR) is a global threat to public health as well as to animal health, food security, the environment and natural resources on which humans depend. More broadly it also threatens sustainable development. AMR undermines the treatment of common infections and is exacerbated by the misuse and overuse of antimicrobials in human, animal and plant health. The environment plays a key role in the emergence, transmission and spread of AMR owing to discharges into the environment from sources such as pharmaceutical production, municipal waste and wastewater systems, as well as animal and plant production. Effective governance and regulatory frameworks are essential to address this multisectoral challenge. The Quadripartite One Health Legislative Assessment Tool for AMR (hereinafter ‘OHLAT’ or ‘the Tool’), developed by the Food and Agriculture Organization of the United Nations (FAO), the United Nations Environment Programme (UNEP), the World Health Organization (WHO) and the World Organisation for Animal Health (WOAH), is an innovative framework used to assist countries in enhancing their national legal frameworks for AMR governance under a One Health approach. Such approach recognises that the health of humans, animals, plants and their wider environment, including ecosystems, are interconnected and interdependent. OHLAT assists countries in identifying regulatory gaps within and across sectors and fosters One Health collaboration, including a participatory approach to legislative assessment and reform. While many efforts to address AMR are rightly made at global and regional levels, OHLAT directly enables country action by supporting the development of a robust national legal framework to respond to the spectrum of AMR challenges. While OHLAT focuses on AMR, this Tool also offers a novel model for tackling other One Health issues that require integrated governance. OHLAT serves as a catalyst to guide governments in preparing comprehensive legal frameworks and ultimately supports global health communities, advocating for building resilient, future-oriented frameworks to mitigate the urgent threat of AMR.

Methane (CH4), a greenhouse gas 86 times more potent than carbon dioxide (CO2) over 20 years, has become one of the main drivers of climate change, with atmospheric levels doubling since pre-industrial times. Among its various natural and anthropogenic sources, such as oil and gas systems, coal mines, or landfills, the Darvaza gas crater in Turkmenistan stands out as a unique and persistent contributor. This crater, usually known as "Door to Hell", is located in the Amu-Darya basin, a geological formation replete with large quantities of oil and natural gas, in which methane is predominant. In 1971, a drilling operation for natural gas by a soviet geologist caused the ground to collapse. The resulting crater measured approximately 70 meters in diameter and 20 meters deep. To mitigate the release of hazardous gases, authorities ignited the escaping gas, burning without interruption so far. However, since last year, the fire in the crater has been reduced by the Turkmenistan government, as we can monitor using the VIIRS Fires and Thermal Anomalies product.Our work focuses on detecting and quantifying the Darvaza methane emissions, trying to confirm whether there is a correlation between fire reduction and emissions. At the moment, we have detected more than 20 methane emissions using the hyperspectral imaging spectrometers EnMAP, PRISMA, and EMIT spaceborne instruments. The emissions range is between 1.000-3.000 kg/h, amounting to thousands of tonnes of CH4 annually.In addition to quantifying emissions, we examined the chronology of the crater flames. By analyzing radiance and thermal bands from Landsat 4-5, we determined the onset of the crater fire in late 1987 or early 1988, a detail previously shrouded in uncertainty. This revelation contributes to the temporal analysis of this crater and provides key information for estimating the total amount of methane released by the Darvaza crater to date.Lastly, the unique conditions at Darvaza—continuous methane release and decades of intense fire—may have significantly altered the surrounding environment. To explore this possibility, we investigate soil composition and mineralogy changes using geological indices. This analysis aims to understand the broader environmental impact of the crater, offering insights into the long-term effects of such phenomena.