Indonesia lets Malaysian planes into its airspace to make rain over the fires

Malaysia is sending aircraft to make rain over Indonesian ground. The South China Morning Post reports that Jakarta has agreed to let Malaysian cloud-seeding flights work inside Indonesian airspace along the two countries' shared border on Borneo. The smoke now sitting over Kuala Lumpur comes from the fires burning across Kalimantan and Sumatra.

Cloud seeding means flying into a cloud and releasing salt or a similar powder, so water droplets gather around the particles, grow heavy and fall as rain. It cannot make weather from nothing: there has to be a cloud with enough moisture in it already. The point of doing it here is to wet burning ground and wash smoke particles out of the air. Malaysia's national disaster agency and its meteorological department are planning the flights along the border, with the Indonesian military handling coordination on the Indonesian side.

Arthur Joseph Kurup, Malaysia's minister for natural resources and environmental sustainability, said 16 areas of the country were reading unhealthy air by 10am on Wednesday. Nearly 600 schools have already closed in Sarawak, and the Petronas Twin Towers have spent days half hidden in the haze. Experts told the Post that seeding buys relief for a few days at most, and that the fight that counts is stopping the burning where it starts.

Why it matters

If you live in Kalimantan or Sumatra, any rain these flights produce falls on you before it helps anyone in Malaysia, so this is your air too, not a favour to the neighbours. The other thing to notice is what it says about the size of the problem: a government that guards its airspace carefully has opened it to foreign aircraft. Watch whether the two countries keep working together after the smoke clears, on keeping peatland wet through the dry season, or whether the cooperation ends with the last seeding flight.