<
https://www.sciencealert.com/the-southern-hemisphere-is-slowly-drying-out-scientists-report>
"It is a well-known fact that water is the key to life on Earth. But it is less
well known that only about 1 percent of all water on the planet is fresh water
available to humans, plants, or land-based animals.
The rest is in the oceans, or locked up in polar ice sheets and rocks. In a
climate changing world, the global distribution of that 1 percent takes on a
whole new significance.
A new study has shown that the Southern Hemisphere has been drying out more
than the Northern Hemisphere over the past two decades (2001-2020). The authors
suggest the principle cause is the weather phenomenon known as El Niño, which
occurs every few years when ocean water in the eastern Pacific is warmer than
usual.
The findings are based on data from satellites and measurements of river and
stream flows, which enabled the authors to model and calculate changes in water
availability. Water availability is the net difference between the amount of
water supplied to the landscape, in the form of rainfall on land, and the water
removed to the atmosphere by general evaporation or by plants through their
leaves.
Even though the Southern Hemisphere has only a quarter of the global land area
(excluding Antarctica), it appears to have a substantially greater effect on
global water availability than the Northern Hemisphere.
The new analysis reveals a strong decrease in water availability in South
America, most of Africa, and central and northwestern Australia. However, some
regions such as the southern part of South America will have more water
available.
By contrast, despite significant variations between regions, the study suggests
water availability in the Northern Hemisphere is more or less balanced. This is
in part due to extensive human influences such as irrigation, dams and food
production. Such factors are more relevant in the Northern Hemisphere since
about 90 percent of the world population lives there.
But why does any of this rather technical modeling about water availability and
drying matter? What are some possible implications if the Southern Hemisphere
is drying out more than the Northern?"
Via Rixty Dixet.
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
