We are circling over Buenos Aires. The airspace is crowded with other planes, all of them holding like ours. The pilot explains that it is the fault of the humo, or smoke, a word I will hear a great deal in the coming week.

An hour and a half later I am on the ground, head pounding, breathing in the humo. The cover of the Clarín newspaper shows someone gagging and declares: “The Worst Atmospheric Contamination in History.”