Weather manipulation research has received some $2bn of investment over the past two decades. It is expected that within the next five to ten years these technologies will begin to be deployed to combat drought, with the further potential to reseed deserts, divert potential floods and make weather "to order".
So why would anyone argue that it is not beneficial?
To answer this question we have to go to the root of any perceived problem that this technology is designed to solve.
Consider the case of drought - perhaps the most compelling of reasons to deploy the technology. Drought is on the increase. This has been predicted for at least 15 years by those scientists who detected human-induced global warming. The predictions are coming true. The root cause of global warming has been the accelerating growth in our use of fossil fuels since the dawn of the Industrial Revolution in Britain. While technology may play a crucial role in mitigating and adapting to global warming, we would be foolish to imagine that it will solve all the problems which may arise.
Droughts have always occurred, though. Humans have learned to cope with periodic drought by planning ahead and by sharing resources. Most of those caught in the major droughts of recent years - notably in East Africa during 2002-6 - have been unable to plan in this way, and have relied on aid from other countries. The root cause of these problems are economic and not technological. The flow of wealth in the world is still from poor countries to rich ones, and until this flow is reversed, poorer nations will not be able to plan for drought.
There is a serious problem with the promise of an end to drought. The main technology on the horizon - that of top-cloud seeding - cannot alter the course of the clouds or create them out of nothing. The conditions must be there to begin with. And in the world's main drought area of subsaharan Africa, the conditions are not there. This technology would not make any difference. We should be deeply suspicious of those who develop technologies like this, often using taxpayers money, on the promise of something which they will not be able to deliver, or which they do not intend to deliver. Follow the money and you'll find out who's really going to benefit.
None of this means that weather manipulation technology should not be used, but we must be careful to consider whether it is a sticking plaster on a much more serious wound.
Far more controversial would be the idea of ordering weather. The Chinese authorities have already conducted experiments ahead of the Olympic Games in Beijing in which they "seeded" clouds by exploding iodine compounds into them, causing them to rain earlier than would otherwise be expected. The moral questions here are much more challenging. Who decides what weather is most beneficial? Indeed, who benefits? What is the potential for litigation if someone has caused weather which may adversely affect others? These problems may not need answering in a dictatorship, but they could not be avoided in a democracy.
In my view no technology is intrinsically good or bad, but the choices we make about which technologies to develop and how we use them inevitably are. The nuclear bomb itself is not evil. What is morally questionable is why we chose to invest so much over so long in the expectation of war when a similar investment to ensure peace could have prevented every war seen since. As has been said so often, once invented it couldn't be uninvented, so it is bound to be used. In the case of weather manipulation, I can imagine far more beneficial investments of the extraordinary wealth of knowledge built up by science. What about schools? Hospitals? Sanitation? Housing? What about canceling debts? What about making trade rules fair? These investments would make all of us more secure and more human. Changing the rain won't.