Frame-by-frame analysis of the motion of individual soot particles then reveals how quickly gases within the fire are moving, and allows fire behaviour to be scrutinised in detail.

ECONOMIST: Next, the fire forecast

First, when released into the air as a result of incomplete combustion (from sources as varied as badly serviced diesel engines and forest fires), soot particles absorb sunlight, and so warm up the atmosphere.

FORBES: Soot and CO2 In The Arctic

Campaigners worry that incinerators produce dioxins (a highly toxic family of chemicals that can cause cancer and birth defects) and tiny particles of soot (also carcinogenic).

ECONOMIST: Tough landfill targets prompt a return to flaming rubbish