Desperate to clear toxic haze, Indonesia to douse its skies with dry ice

Image source, EPA/ShutterstockImage caption, Indonesia is battling its most dire wildfire season in a decade

As toxic smog continues to billow from wildfires in Indonesia's forests and peatlands, authorities are looking at an experimental way to disperse the haze.

A trial on Thursday will see an aircraft scatter pellets of dry ice – solid carbon dioxide – in the air above South Sumatra province, one of the regions worst hit by the haze.

Indonesia is battling its most dire wildfire season in a decade, as an unusually strong El Niño has exacerbated drought conditions and made flames harder to put out.

Amid increasingly urgent efforts to clear the hazardous air, authorities in Indonesia and neighbouring Malaysia have turned to various weather modification methods.

These include cloud seeding, a technique that speeds up the natural process of water vapour condensing inside of clouds by dispersing compounds such as silver iodide to form ice crystals.

Authorities have been carrying out such operations for weeks.

But Thursday's dry ice trial is different.

Rather than interacting with clouds to trigger rain, the dry ice is meant to "break down" haze in the lower atmosphere "so that it can rise upward", said Dudung Abdurachman, the coordinating minister for political and security affairs.

"If this trial is successful, we will continue with other areas that are central to the haze, such as Central Kalimantan and its surroundings."

The trial will involve 1.5 tons of dry ice, according to authorities.

Indonesian President Prabowo Subianto has called for agencies to step up efforts to extinguish the wildfires and mitigate the impact of toxic smog billowing from the hotspots.

New cloud seeding operations are also set to take place in Central Kalimantan – another haze-stricken area – on Thursday and Friday.

Meanwhile, firefighters on the ground are continuing to tackle out-of-control blazes and authorities have deployed dozens of helicopters to extinguish the wildfires – though these operations have at times been disrupted by poor visibility in the haze.

Residents across Kalimantan and South Sumatra are bearing the brunt of the toxic smog, with air in many cities turning a dusty amber.

Pollutants have also drifted across borders to neighbouring Singapore and Malaysia, raising public health concern as air quality scores soar to unhealthy levels.

In parts of Malaysia with particularly hazy air – including its capital Kuala Lumpur and the city of Johor Bahru, near Singapore – local authorities have conducted their own cloud seeding operations.

Last month, Indonesia granted permission for Malaysian agencies to enter its airspace for cloud seeding operations along the countries' shared border.

More than one million wildfire hotspots have been recorded in Indonesia this year, burning almost 900,000 hectares of land, according to independent forest monitoring platform Nusantara Atlas.

Much of the public frustration is directed at agricultural companies that burn vegetation as a cheap way to clear large swathes of land.

Indonesian police have named more than 200 individuals and nine companies as suspects in connection with the fires.