THE annual haze that blankets swathes of South-East Asia usually begins to recede in October. This year however the smoggy conditions—caused by fires set to clear farmland in rural Indonesia—only got worse. On October 26th Joko Widodo, Indonesia’s president, cut short a state visit to America to handle the crisis, which has become one of the worst in memory. With the onset of this year’s rainy season delayed by the “El Niño” weather cycle, it could be a month or more before all flames are doused.

The word “haze” hardly does justice to the poisonous clouds that have been billowing across the region since August. On bad days Singapore and parts of Malaysia have been enveloped by a reeking white mist that has closed schools and delayed flights. Lately it has also reached southern Thailand and the Philippines. Meanwhile the millions of Indonesians who live close to the hotspots, mostly on the islands of Sumatra and Borneo, are breathing a soupy yellow fog which authorities say has killed at least ten people and caused respiratory problems in more than 500,000.

The blazes are not only a disaster for those who live in the region. Greenpeace says that years of draining and burning peatland, to make way for oil palms and other crops, has turned Indonesia into a “carbon bomb”. Guido van der Werf, a Dutch researcher, reckons that emissions from a three-week period during this year’s fires surpassed Germany’s total annual carbon output. On a daily basis, they may emit more carbon than does America’s economy—which is more than 20 times the size of Indonesia’s. Conservationists also fret about the impact on Indonesia’s endangered wildlife, not least the orangutan colonies in Sumatra.

Indonesia has enlisted more than 20,000 people to control the fires. After some hesitation, it has also accepted help from its neighbours, including Singapore, Malaysia and Australia. The rain that fell on October 28th was useful. But with more than 100,000 fires to fight, the Indonesian authorities badly need more downpours. In the meantime they have built reception centres with oxygen tanks and air-purifiers in the worst-affected areas. A clutch of navy ships is waiting off the coast of Borneo—apparently ready to serve as floating shelters for women and children, should parts of the island need evacuating.

Optimists hope that this year’s emergency may at least bring the region closer to solving a problem which has struck repeatedly and with varying intensity for decades. A severe haze in 2013 helped prompt many of the biggest agricultural firms to promise better management of jungles and peatlands; some think Indonesia will now be more inclined to push ahead with much-needed regulations to rein in the smallholders and medium-sized firms who bear the most blame for this year’s conflagrations. Lately, clouds of haze have been drifting into the outskirts of Jakarta, Indonesia’s capital, which normally escapes the smelly fumes. Cynics will wonder whether that helped persuade Mr Widodo to come home early.