Take a look at Nicola Davies' article about the floods and the recent Met Office/CEH report. This is rather level-headed stuff, with none of the wailing and gnashing of teeth that usually accompany the paper's utterances on the subject. Here's the conclusion:
Is climate change ultimately the cause?
It is not possible to link the current floods definitively to climate change. "In terms of the number of storms there is scant evidence that has been increasing due to climate change so far," said Scaife. "[But] we do expect that winter rainfall is likely to increase in the future." This is in part down to a warming planet. "As the air warms it can hold more water."
That seems to me a scientifically supportable case. I wonder how much more water the air can hold if it's, say, 2 degrees warmer?