ONE of the countries most seriously affected by this year’s mighty Niño weather phenomenon is Indonesia. By the middle of October more than 20,000 firefighters were battling blazes across its jungles and peatland. More fires have been detected in 2015 than in any year since satellite records began. Only the onset of heavy rains has brought some respite from the toxic smoke which has shrouded South-East Asia since August.

Indonesia has long suffered from forest fires during the annual dry season. Many are set deliberately, by farmers and firms clearing land for crops such as oil palm. The blazes have grown more serious as agriculture has expanded onto peatlands, which become volatile when drained. This year’s El Niño has lengthened and intensified the dry season, creating a calamity. A reeking white mist which caused school closures and flight cancellations in Singapore and Malaysia has spread as far as Thailand and the Philippines. Data from Guido van der Werf, a Dutch researcher, suggests the emissions from this year’s fires have caused Indonesia to surpass Japan as the world’s fifth biggest polluter.

On the worst days the fires have emitted more carbon than America’s entire economy—which is more than 20 times the size of Indonesia’s. And it may not be over. Louis Verchot of the Centre for International Forestry Research warns that El Niño may yet induce a second burning season, next February and March. Lax laws are part of the problem. Even more serious are official incompetence and corruption, which have allowed plantations to keep spreading on land that is supposed to be off-limits. A regional treaty designed to combat the haze was drawn up in 2002 that was full of grand promises but lacked teeth. A new law introduced in Singapore this year that aims to drag Indonesia’s fire-starters through its own courts may make more difference. Retailers in the city-state have already stopped selling products made by some firms under investigation.

Indonesia’s newish president, Joko Widodo, seems more concerned about the fires than any of his predecessors. A forestry graduate himself, he has toured the worst-affected regions, and last month returned early from a long-planned state visit to Washington to oversee the crisis. His administration looks prepared to prosecute at least a handful of executives from fire-linked firms, a small but strongly symbolic step forward. In recent weeks the country has ploughed resources into lifting the smog. It must not stop when the skies return to blue.