In one of T.S. Eliot's more sombre works, that poem with the unlikely name The Love Song of J. Alfred Prufrock, there are lines that are bleakly apposite to current events in Indonesia. "The yellow smoke that rubs its muzzle on the window panes,
Licked its tongue into the corners of the evening." But although the present level of pollution is exceptional, visibility reduced by smoke haze in the region is not at all unusual.
Large tracts of South-East Asia exist beneath a semi-perpetual shroud, an all-pervasive ground-hugging haze made up of cooking smoke and dust, and often extending from Bombay across India to Calcutta, and over to Hong Kong. In India it is called godalli, a Sanskrit word for "cow dust".
The viability of such a haze depends crucially on the thermal structure of the atmosphere. In what might be called "normal" conditions, air temperature decreases with height in the lower layers of the atmosphere, which, like many of nature's arrangements, confers distinct advantages.
Warm air, as we know, is lighter than cold, so in such circumstances the warmer air near the ground tends to move upwards, to be replaced by colder air sinking down from above. This constant mixing of the atmosphere causes pollutants near the surface to be widely dispersed.
But if the usual temperature profile in the vertical is "inverted", and air temperature increases or remains more or less constant with increasing height, smoke or other pollutants are trapped at ground level. Such problems, of course, are also common in the western world. London's air pollution problems, for example, began as early as the reign of the Plantagenets.
In the 13th century bituminous coal was introduced, brought down from the Scottish Firth of Forth, and burned by brewers and smiths throughout the city.
Control was swift but ineffective: the first Smoke Abatement Law, enacted in 1273, declared the burning of coal to be prejudicial to health, and prohibited its use - but history suggests that no one took much notice. The depletion of the English forests during the 15th and 16th centuries increased the use of coal by raising the price of wood, and by 1578 Elizabeth I was sufficiently annoyed by the problem to try again: she forbade the use of coal in London during parliamentary sessions.
By 1661 smoke pollution was sufficiently acute for the diarist John Evelyn to deliver a polemic on the subject. It was published under the modest title: Inconvenience of Aer and Smoke of London Dissipated - Together with some Remedies Humbly Proposed, and is more commonly remembered by its virtually onomatopoeic Latin title, Fumifugium.