LA turns to rainmakers

As I have written before I was privileged to have been awarded a Nuffield Scholarship to study water and spent part of my time in California. Therefore I read with interest the report in the Guardian about the use of silver iodide to boost rainfall in Los Angeles. Silver iodide can be used to increase rainfall in a particular area although the impact, as with all natural processes, can be difficult to scientifically quantify. The silver iodide is seeded into the clouds and this process is undertaken in several parts of the Western States of America. However, the process raises an issue - if you induce rainfall in one area are you denying others from accessing the water that otherwise would have fallen as rainfall (or snow) naturally somewhere else? The answer is probably yes .. but as the demand for water increases in many regions of the world this practice is likely to increase too. However there is huge potential for conflict between communities where one of those communities feels denied and disadvantaged as a result of actions taken by another. It will be interesting to see how this issue which has such a human imprint develops.