In 1995, a multimillion-dollar experiment – the Indian Ocean Experiment – discovered a dark mass of polluting air hovering above the Indian subcontinent. This mass of air was termed a cloud and found to be composed of a high amount of black carbon that was judged to be the second biggest threat to climate change after carbon-dioxide. In this article, an attempt is made to trace the life of black carbon by documenting its changing forms since the experiment. It emerges that the changing forms allow for the movement of air – smoke from traditional cookstoves and vehicular diesel emissions in India lead to the formation of the cloud – and reveal how an ethnography of air can be undertaken.

1995年，一项价值数百万美元的实验（印度洋实验）发现了漂浮在印度次大陆上空的一团污染空气。这种空气被称为云，被发现由大量的黑碳组成，被认为是仅次于二氧化碳的第二大气候变化威胁。本文尝试通过记录自实验以来黑碳的变化形式来追踪黑碳的寿命。结果表明，不断变化的形式允许空气流动-印度传统炊具产生的烟雾和印度车辆柴油的排放导致云的形成-并揭示了如何进行空气民族志研究。