NASA reveals major changes in worldwide water availability

Rodiano Bonacci
Mag 17, 2018

The outcomes, which are likely a mix of the consequences of climate change, enormous human withdrawals of groundwater and easy all-natural adjustments, could have serious impacts should they persist, pointing into a situation where some highly populous areas may struggle to find sufficient water in the long run. "We see a distinctive pattern of the wetland areas of the world getting wetter - those are the high latitudes and the tropics - and the dry areas in between getting dryer".

The study emphasizes that the 34 separate changes that it detects do not all have the same cause - not even close.

Although both satellites stopped gathering data past year, the next generation of twin satellites (GRACE Follow-On) are set to launch Tuesday from California.

In some regions, like those with melting alpine glaciers and ice sheets, climate change is a clear driver of water loss, according to Famiglietti. On land, it's possible that some droughts and rainfall increases may be also, though the study is cautious about that, noting that natural variability can also be a major factor here. "We just have 15 decades of data from GRACE, but it sure as hell matches that pattern, it fits it today", explained Famiglietti.

And there are additional human induced alterations, relating to not climate change but instead to direct entry of water in the landscape.

The fluctuations in the Aral Sea area, formerly recorded by NASA, are especially intense.

Mainly, however, what is striking about the map is the manner a combo of human-driven water concessions and droughts appear to be penalizing the central latitudes of the northern hemisphere particularly, but also the southern hemisphere to some substantial extent.

"I believe we've forgotten, society has abandoned, just how much water needed to make food", Famiglietti said. "We have accepted its availability for granted". And you know, now we're at a point in many of these aquifers where we can't take it for granted any more.

Still, it's important to bear in mind that, while the GRACE data have given a new panoptic view of the changing distribution of water around the globe, the data remain coarse and the causes behind the trends in many cases remain a matter of interpretation, cautioned Peter Gleick, an expert on climate change and water who is president emeritus the Pacific Institute.

The following GRACE satellite mission provides greater information, he concurred.

"We're in this transition between not really having a global overview, and someday having an incredibly high-resolution sophisticated remote sensing overview", Gleick said. "That is where we're".

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