Doubt has been cast over Indonesian efforts to "seed" clouds to make rain before downpours reach flooded Jakarta.
The Indonesian army has begun the controversial technique to prevent further inundation in Jakarta, following devastating floods earlier in January.
Hercules aircraft are being used to disperse five tonnes of salt at a time below the clouds using flares.
The hope is that rain falls over the sea before it reaches Jakarta.
Dr Chubb, a research fellow at Monash University, told Radio Australia's program international research has found limited evidence supporting this type of cloud seeding,
"It's difficult to say whether there has been much success given there have been a limited number of campaigns to assess this," he said
He said Australia has two similar campaigns aimed at increasing snowfall over mountain catchments to provide more water for hydro-electricity and agriculture.
The programs in Tasmania and the Snowy Mountains use silver iodide to mimic the structure of ice and encourage ice growth.
© ABC 2013
23:22 EDT A south-west Queensland grazier has captured on camera the moment a "rain bomb" dropped from the sky.