For at least two months now, forest fires have been raging across Indonesia.

Every year, between August and October, vast tracts of forest land are cleared for palm oil, pulp and paper plantations. The planters mainly use the "slash and burn" method - cut the vegetation and burn it - since it's the fastest way to clear the land.

This year, the fires have turned into a catastrophe because of the unusually dry weather brought on by the El Nino.

In just the last six weeks, Indonesia has moved from sixth to the fourth largest emitter of carbon dioxide in the world. This is no small feat.

For months, Indonesia and vast areas of Southeast Asia have been enveloped by haze and smoke. The scale of loss is unimaginable. George Monbiot calls it the "greatest environmental disaster of the 21st century so far".

The harm to people's lives is incalculable. Schools have been shut and flights cancelled. Indeed, gangster Chhota Rajan's extradition from Bali has been delayed in part because the flights have been grounded.

Here are some numbers to put the scale of the devastation in perspective.