Saturday, June 28, 2014

New paper finds global precipitation is increasing, decreasing, & not changing

6/28/2014


Settled science: According to a paper published today in Atmospheric Science Letters, global precipitation has either decreased, increased, or not changed over the past 30 years, depending upon which of 3 global datasets are examined: 
"Decadal trends of global precipitation are examined using the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP), Global Precipitation Climatology Project (GPCP), and National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis data. The decadal trends of global precipitation average diverge a decreasing trend for the CMAP data, a flat trend for the GPCP data, and an increasing trend for the reanalysis data." 
Thus, the actual trend of global precipitation, if any, remains a mystery. Several peer-reviewed papers have shown climate models are unable to simulate decadal trends in precipitation, unable to simulate regional trends in precipitation, and that the claim "wet gets wetter, dry gets drier" is without basis. 

Decadal trends of global precipitation in the recent 30 years

Xiaofan Li et al

Decadal trends of global precipitation are examined using the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP), Global Precipitation Climatology Project (GPCP), and National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis data. The decadal trends of global precipitation average diverge a decreasing trend for the CMAP data, a flat trend for the GPCP data, and an increasing trend for the reanalysis data. The decreasing trend for the CMAP data is associated with the reduction in high precipitation. The flat trend for the GPCP data is related to the offset between the increase in high precipitation and the decrease in low precipitation. The increasing trend for the reanalysis data corresponds to the increase in high precipitation.

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