"Likelihood of extreme rainfall may have been doubled by rising greenhouse-gas levels"
Two very topical scientific papers have just been published in the prestigious journal Nature showing a connection between human caused climate change and the increasing intensity of rain and snow and the increased risk of serious flooding. For more see here and here.
It has long been known that a warmer atmosphere holds more water and an observed increase in extreme precipitation events has been documented but this increase had not been formally tied to human caused climate change. Two groups of scientists have now found humanities' fingerprints on the increased rainfall in the northern hemisphere in the later 20th century and in increasing the likelihood of a specific extreme flood in Britain back in 2000 (perhaps up to twice as likely).
So while it is still true that climate change does not solely cause an extreme weather event such as a unprecedented flood, it is clearly possible for climate change (and hence human activity) to make one more likely.
The present studies looked at the northern hemisphere and a flood in the UK only, so the results do not directly extrapolate to the flooding we have recently experienced. Such a "fingerprinting" analysis may well already be underway but it will be some time before we hear the result. The results though, show that the effects of climate change are already being felt and point towards a future where (globally) extreme rain and flooding events are much more common if we don't curtail our greenhouse gas emissions.