Of course the chances are low, but it's a cumulative probability. It only has to happen once an a large area is fucked for generations. And you know full well what we're like with upkeep costs on infrastructure in this country. Fuck that, let's give a massive wedge to the shareholders instead. The when it becomes a massive problem we'll just let it be nationalised and let the public purse pay for it.
Fact is the money we've spunked on nuclear and keeping gas/coal going over the years would have been sufficient to have had a viable renewable energy network in place by now. So we wouldn't be talking about needing to scrap green levies, or wholesale gas prices, or being bent over by the oil cartels and having to ignore all sorts of human rights abuses because it'd all be irrelevant and we'd have a much healthier environment to live in to boot. Those that are complaining about how the green levy is making energy unaffordable are making it that way because they refuse to give up antiquated energy sources out of financial self-interest.