Climate change widening world's wet-dry region divide: study

Earth's wet regions are getting wetter and dry regions are getting drier due to global warming, according to a new study.
Researchers from University of Southampton in the UK found that the regions, which are relatively wet, like Northern Europe are getting wetter and dry regions are getting drier. This process is called amplification of the water cycle.
More rain and outflow from rivers in a region of an ocean means sea water gets diluted and therefore becomes less salty.
More evaporation in another region takes away fresh water and leaves salt behind making that region more saline.
Researchers used measurements of salinity throughout the global and deep oceans over the last 60 years to estimate how much global rainfall is changing.

Previous research indicates that amplification of the water cycle is happening at seven per cent per one degree Celsius of global warming.

The new study estimates that amplification happens at about three to four per cent per one degree Celsius.
Researchers believe this is probably due to a weakening of the atmospheric circulation which transports freshwater from the dry to wet regions of the globe.
"Our findings match what has been predicted by models of a warming climate; as the world gets warmer wet regions will continue to get wetter and dry regions will continue to get drier," said Nikolaos Skliris from the University of Southampton.

"Although we have found that this process is happening slower than first thought, if global warming exceeds three degree Celsius wet regions will likely get more than 10 per cent wetter and dry regions more than 10 per cent drier, which could have disastrous implications for river flows and agriculture," said Skliris.
"The agreement between climate models and observations over the recent past is another important finding of this study because it adds confidence to climate model projections of water cycle amplification under greenhouse gas emission scenarios," Skliris added.
The study was published in the journal Scientific Reports.