What was done
The authors performed a series of statistical tests to investigate the nature and potential causes of trends in winter (Dec-Feb) mean precipitation recorded at forty stations in northern Italy over the period 1960-1995.

What was learned
Nearly all of the forty stations experienced significant declines in winter precipitation over the 35-year period of study; and by subjecting the data to a Pettitt test, the authors detected a significant downward shift at all stations around 1985.  An Empirical Orthogonal Function analysis was also performed on the precipitation data, revealing a principal component that represented a common large-scale process that was likely responsible for the phenomenon.  Strong correlation between this component and the North Atlantic Oscillation (NAO) suggested that the changes in winter precipitation around 1985 "could be due to an intensification of the positive phase of the NAO."

What it means
With both more floods and more droughts being predicted by climate alarmists to occur in response to the rising CO2 content of the atmosphere (how can they possibly lose?), simply learning that winter precipitation in Italy declined between 1960 and 1995 would probably be reason enough for folks of that ilk to sound the alarm about global warming being its cause.  Indeed, such is becoming a common occurrence whenever a significant change in the weather is detected.  Yet, with ever more scientists performing quality investigative analyses of the type described here, the likelihood that CO2-induced global warming actually causes such changes is appearing less and less plausible.  Quite to the contrary, in fact, natural climatic oscillations and perturbations like the NAO are looking more and more like the real culprits with each passing day.