In 2011 Colin Ward authored an article for CSIROpedia about Cloud seeding. He talked about how Taffy Bowen and his staff at the Division of Radiophysics searched for work of interest to themselves and importance to Australia after the end of the second World War. One of the thing Bowen took interest in was cloud and rain physics which he began and led until 1971 when he retired.
Ward’s article says, “Today, CSIRO uses the lessons learnt from their cloud seeding experiments to develop better models for weather forecasting and changes in climate.” And then he talks about USA researchers I Langmuir and V Schaefer who reported in 1946 that rain could be induced by seeding clouds with dry ice.
There has been much speculation around this topic on various social media platforms. Many people do not even believe it is possible to induce rainfall – but with this article, I hope to shed some light on the reality of what is going on.
Firstly, there are several organisations that practice cloud seeding, and there are varying methods used. A trial was conducted by Taffy Bowen’s team in Eastern New South Wales, in Australia using RAAF aircraft on February 5th, 1947. On the day, the trial was carried out, there was deep cumulus cloud coverage, where all the clouds appeared similar in type and size and covered the country inland from Sydney. After the plane dumped dry ice into the cloud, rainfall took merely minutes to commence, and the rain lasted several hours with more than twelve millimetres over an area of 80 square kilometres – The surrounding clouds did not have rainfall from them, and this experiment is believed to be the first documented trial.
In 1947 a systematic program of cloud seeding was initiated, and it continued for twenty-four years. The Division focussed their work on airborne investigations of cloud structure and reaction, theoretical and laboratory but the biggest difficulty faced was that nothing definitive could be proven since there was no way to know how much rain a cloud would have produced had the seeding not been done – however, with repetitious experimenting, eventually it was proven because the rain continued to increase.
The Division of Cloud Physics and the State Departments of Agriculture worked side by side in the cloud seeding research and public meetings were held before the commencement of any program to give the people a voice on the subject. The Division still received letters from angry landowners blaming the experiments for unwanted downpours.
In 2018, an article written by Kate Doyle about cloud seeding was posted on ABC News. One quote from her article is “Cloud seeding is the process of adding chemicals to clouds to increase rainfall.”
She also mentions that Hydro Tasmania conducted cloud seeding in the lead-up to deadly flooding in north-western Tasmania.
One must wonder, if it has been done for this long, they would have surely refined the methods they use, and so the elephant sitting in the room is one that must be spoken about… in what way have their rain seeds impacted the current floods in NSW and QLD?