As Delhi goes through its worst phase of consistent bad air quality, residents in the capital have been demanding immediate measures to curb city's unrelenting smog. While the administration has finally woken up to the seriousness of the issue, the relief measures taken by the government may take days before we see clear blue skies in the city.
Some have suggested an artificial bout of rain to clear the toxic particulate matter present in city's air.
What is cloud seeding?
Cloud seeding or weather modification is an artificial way to induce moisture in the clouds so as to cause a rainfall. In this process, either silver iodide or dry ice is dumped onto the clouds by using an aircraft or an artillery gun which leads to a rain shower.
Where has it been used?
China frequently uses weather modification system to create rainfall during droughts. In July this year, China allocated 199 million yuan ($29.76 million) to spend on its cloud seeding program to prevent drought.
In June this year, a team of scientists from Beijing offered China's cloud seeding technology to India to fight droughts in Maharashtra's Marathwada region.
During 2008 Beijing Olympics, Chinese organisers fired a barrage of rockets in the air ensuring clear skies for the opening ceremony.
In 2009, Chinese scientists fired Beijing skies with iodide sticks hoping to end a long spell of drought, the seeding however caused an early snowfall which disrupted air and road traffic.
In United States, cloud seeding is occasionally used by ski resorts to induce snowfall. Cloud seeding is being used to recharge the ground water in arid UAE.
Last year, Malaysia and Indonesia used cloud seeding to stimulate rainfall after tocix smoke gripped the region.
How effective is it?
The success of cloud seeding depends on the weather conditions of the area. Some moisture in the atmosphere is needed to cause precipitation.
Environmentalists have raised concerns regarding secondary air and water pollution as an outcome of chemicals used to cause precipitation.
Can it work in Delhi?
According to experts, Delhi's dry weather is not suitable for cloud-seeding. First, some clouds are needed to carry out the seeding process. Second, the humidity in the air is too less for it to succeed in Delhi. But considering the severity of air pollution and the threat it poses to more than 40 million people in Delhi-NCR, this method could be worth a try.