Cloud-seeding a drought cure?

Toowoomba says ‘NO’, so what about cloud seeding?

In the light of Toowoomba’s 60-40 ‘No’ vote to recycling sewage as a drought cure, the accusations made by a Nationals MP – reported in The Australian – saying government scientists are “scuttling research into cloud-seeding” are worth thinking about.

John Forrest is a civil engineer and member of the parliamentary standing committee on agriculture, fisheries and forestry. He started a 2002 House of Reps inquiry into future water supplies for rural industries and communities and he wants government scientists to ‘keep an open mind on cloud-seeding’. He believes scientists at CSIRO and at the Bureau of Meteorology in Melbourne have provided incorrect advice on the effectiveness of cloud-seeding projects which occur around the world in:

• China
• US – California; Utah;Texas
• Israel
• Thailand
• France

He blames the scientists’ stance on competition for funding and professional jealousy!

Cloud-seeding & Australia’s approach
Wikipedia says “While cloud seeding has shown to be effective in reducing the amount of cloud cover, it is more controversial whether cloud seeding increases the amount of precipitation from a cloud. Part of the problem is that it is presently impossible to know how much precipitation would have occurred had the cloud not been “seeded”.
A cooperative research centre for weather modification to carry out some practical testing for cloud-seeding has been called for. The chief of Atmospheric Research at CSIRO has previously called the technique ‘unproven’, ‘controversial’. Bureau experts advise there is little scientific evidence to support its efficacy.
Malcolm Turnbull, parliamentary secretary with responsibility for water policy, is sceptical of claims of wrongoing on the part of scientists. The parliamentary secretary with responsibility for the Bureau of Meteorology has praised Forrest’s “willingness to explore any and all options for helping with water supplies”.

Check out some reports on cloud-seeding results here, here, here and here.

How cloud-seeding works

• Data from satellites identifies clouds suitable for seeding
• A plane flies through a cloud upwind of the required water catchment at a height where the temperature is about 10 degrees
• A ‘burner’ attached to the plane sprays a fine mist containing a small amount of (usually) silver iodine solution
• The burner ignites the mist as it mixes with air, producing tiny crystals of silver iodide
• Ice crystals form around the silver iodide crystals, which then fall to the catchment as rain
• Ground-based burners can be used along mountain slopes, relying on draft to seed clouds.