Trident or Renewable Power?

The article Ian Davis has written for CommentisFree is relatively sane for a Guardian article about climate change but relies upon a few premises which simply cannot stand:

1. That Britain abolishing its nuclear deterrent would make enough of a difference to the global balance of threats, power and instability to cause the other nuclear powers to give up their bombs and the non-nuclear powers to stop their effort to obtain them. This is absurd as the UK is not the US or Russia and not a major player in terms of reducing the big arsenals of weapons and even if all the world's bombs were decommisioned Iran would still want one to offset its massive weakness in conventional arms relative to the States.
2. That the cost of replacing Trident is the same as that of producing the renewable capacity to provide for half of our energy needs. Trident isn't that expensive, the big costs quoted are spread over the years of development, and we already provide substantial subsidy to renewable energy development; much of the low hanging fruit will already have been claimed.
3. That our investment in developing renewable energy technology will pay off. Government has a hideous record in picking technologies and something could well come up which makes wind power an expensive mess, fusion power perhaps. Equally, the skeptics could be proven correct and the demand for global warming friendly technology could dry up in the medium term (when fossil fuels run out different technological priorities might be prevalent).