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Amazon River Breezes Mimic Pollution in Clouds

Map of the Amazon Basin.
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: AGU Advances

Aerosols are tiny particles suspended in the air. They can cool the climate by making clouds brighter and longer-lasting. Scientists rely on satellite observations to measure the aerosol-cloud interaction, but distinguishing human impacts from natural weather patterns remains a challenge.

Christensen et al. [2026] reveal that the Amazon River itself creates cloud patterns that mimic the signatures of pollution. Using 15 years of satellite data, researchers found that the temperature difference between the cool river and the warm land drives a local “river breeze” circulation. This natural process creates clouds with smaller and more numerous water droplets, which exhibit very similar features that satellites look for to identify pollution. Consequently, clean clouds over the river can appear polluted in satellite datasets. These findings highlight the critical need to account for local geography and natural weather patterns to accurately assess how human activities are influencing Earth’s climate.

Citation: Christensen, M. W., Varble, A. C., Tai, S.-L., Wind, G., Meyer, K., Holz, R., et al. (2026). The Amazon River-breeze circulation limits detection of aerosol-cloud interactions in warm clouds. AGU Advances, 7, e2025AV002188. https://doi.org/10.1029/2025AV002188 

—Xi Zhang, Editor, AGU Advances

Text © 2026. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.
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哪些国家因颗粒物空气污染付出的代价最大?

两座烟囱矗立在一片浓重的烟雾之中,而这些烟雾几乎完全遮蔽了城市的景色。
Source: GeoHealth

This is an authorized translation of an Eos article. 本文是Eos文章的授权翻译。

世界卫生组织的数据,全球每年因空气污染导致的死亡人数估计达 700 万。其中大部分死亡病例是由PM2.5引起的,这种直径小于 2.5 微米的颗粒物能够进入肺部和血液,从而引发呼吸系统和心血管系统疾病。除了直接排放到大气中的颗粒物外,工厂、船只、汽车和发电厂排放的氨(NH3)、氮氧化物(NOX)和二氧化硫(SO2)等物质也是导致 PM2.5 形成的前体物。然而,颗粒物污染的影响并非均匀分布。

Oztaner等人对北半球各区域的空气污染后果进行了建模,从而更细致地分析了哪些地区的减排政策最为有效。他们利用美国环保署(EPA)社区多尺度空气质量(CMAQ)建模平台的多相伴随模型(multiphase adjoint model),从挽救生命和节省资金两个角度评估了减少各种污染物带来的效益。该研究通过国际机构所广泛采用的一种成熟方法,计算出了空气污染影响所造成的经济损失。不过,这种方法也引发了一些伦理方面的担忧,因为它在评估生命价值时部分地依据了各国的人均国内生产总值(GDP)。

总体而言,研究发现,如果所有模型中的排放量减少 10%,那么在北半球每年将能挽救 513,700 人的生命,并节省 1.2 万亿美元的费用。

死亡率降幅最大的是中国和印度,削减排放量每年将分别挽救184,000人和124,000人的生命。成本节约幅度最大的也是中国,其次是欧洲和北美。健康效益也因排放类型和行业而异。氨(NH3)在中国造成的危害更大,而氮氧化物(NOx)在欧洲的危害相对高于其他地区。在整个北半球,农业部门是颗粒物和前体物污染的主要来源,预计农业相关排放量减少10%可挽救95,000人的生命,并节省约2900亿美元。其次是居民区和工业区。

作者指出,在对类似研究的结果进行比较时应保持谨慎,一部分原因是污染物浓度与健康结果之间的关联并非总是呈线性关系,还有一部分原因是不同地区在核算各行业排放量时可能采用不同的方法。此外,他们的研究仅关注与 PM2.5 相关的死亡率,未考虑如臭氧等其他污染物。总体而言,他们认为他们的研究为比较北半球不同污染物减排策略的效果提供了一个有意义的参考。(GeoHealth, https://doi.org/10.1029/2025GH001533, 2026)

—科学撰稿人Nathaniel Scharping (@nathanielscharp)

This translation was made by Wiley本文翻译由Wiley提供。

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Text © 2026. AGU. CC BY-NC-ND 3.0
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