Research by the Lawrence Livermore National Laboratory confirms the powerful impact global warming is having on changing global precipitation patterns. In a nutshell, climate change is moving precipitation bands toward the poles with already wet areas becoming a lot wetter and ordinarily dry regions slated to become far drier.
We've heard these predictions before. The LLNL research confirms them. The study explored not only land-based precipitation but included the 77% of global rainfall that occurs over oceans. It also filtered out the impacts of El Nino or ENSO events.
The new study, based on 33 years of rain gauge and satellite data, tried to overcome these problems by averaging out anomalies in observations to filter out the “noise” of natural variability.
It also focused on both of the key mechanisms thought to drive rainfall changes – “dynamic” shifts in atmospheric circulation and “thermodynamic” increases in water vapour levels in the troposphere.
The scientists found they could not detect measurable changes in precipitation that could be pinned on either of these phenomena in isolation. But deviations caused by the two “increasingly occur in tandem”, the paper says.
“By focusing on both the underlying mechanisms … we have shown that the changes observed in the satellite era are externally (caused), and likely to be anthropogenic in nature,” it says.
“Observed changes … are incompatible with our best estimates of natural variability, and consistent with model predictions of externally forced change.”
"Likely to be anthropogenic in nature." That's a nice way of saying that the era of protracted droughts and megafloods that has been ushered in is largely a man-made phenomenon. It's just one of the things our greenhouse gas emissions have done to dick around with the weather.
The article was published in the Australian paper The Age. Australia, of course, just elected the closet, climate change denier, Tony Abbott, as its prime minister even as that country is experiencing record heating and massive flooding. What was that Sarah Palin like to say? Burn baby, burn.