Scientists in India are claiming that the Asian brown cloud is not something specific to Asia and does not have a knock-on effect on pollution related mortality.

The cloud, almost the size of United States, has been described by experts from the United Nations' environment programme as a blanket of brown haze 3 km deep. They say that it hangs over a vast territory encompassing the northern Indian Ocean, India, Pakistan, and much of South Asia, South East Asia, and China for as long as four winter months a year.

The cloud is caused mostly by …