Lot's of Freshwater, But NOT WHERE It's Needed

Precipitation, commonly called rain, the predominant source of freshwater, is more than enough for a 10+ billion human population plus the other species and nature's ecosystems that must have freshwater.
Rainfall

Source - countryofsb.org

From the very beginning, rain has supplied the freshwater needs of human, other species and nature's ecosystems in two ways: 
- Either, by dropping manna-from-the-heavens directly onto crops and where the freshwater was needed and/or 
- Replenishing lakes and other bodies tapped by humans, other freshwater species and nature's freshwater ecosystems.
Total Rainfall on land

Source - sciencemag.org

A total of 98,500 cubic kilometers of rain is estimated to fall on land every year.
This liquid precipitation is in addition to the 12,500 cubic kilometers that fall as ice and snow on land.
Ignoring for a minute that this rainfall in not geographically uniform and that it has extreme spacial and temporal variations, the 98,500 cubic kilometers/year
= 270 cubic kilometers/day
As 1 cubic kilometer = 264 billion US gallons,
the average rainfall of 270 cubic kilometers/day
= 71,280 billion US gallons/day
For a 10 billion human population (the projected human population in 2050), this rainfall
= 7,128 US gallons per day.
Why Freshwater Scarcity?
Ignoring freshwater accessed over long distances from surface bodies (lakes, rivers, etc) and underground aquifers, with so much rainfall available per person per day, why do we have scarcity anywhere in the world?
The answer: Scarcity is the result of rainfall not being uniform all over Earth's land mass and the unpredictable spacial and temporal variations of rainfall.

Africa - The Not-so-DRY Continent!

The frequent photographs of parched African landscapes are familiar to all of us. Recent research tells a different story than the typical one of acute horrendous freshwater scarcity.
Accounting for Groundwater
A good map of underground aquifers has always existed for much of the world -except for Africa.
Freshwater availability projections for Africa have always omitted accounting for groundwater - till now.
Africa's Aquifers

Source - Environmental Research Letters Journal
Dated 19 April 2012

The productivity of Africa's aquifers has now been quantified.
Apparently there is a lot of water underground in much of Africa.
The orange and yellow areas, in the accompanying larger map, only cover 15-20% of the African continent, and identify aquifers with lowest expected productivity.
The blue and black colored areas are those with aquifers with the highest productivity.
In the smaller map, the same orange and yellow colors identify the worst condition i.e. the areas where the aquifers are the farthest underground.
Bottom Line
Underground aquifers contain:
1. More than 100 times the annual renewable freshwater resources, and
2. More than 20 times the freshwater stored in all of Africa'a lakes and other surface reservoirs


Now all we need to do is figure out a way to get this water to Africa's people who can drink it and use it for growing much-needed food.

"Water Stress" Has Many Definitions

Just like the saying "Beauty is in the eyes of the beholder", Water Stress has different meanings around the globe. Remedying water-stress is difficult when few can agree on what the term means for all of them.
Water Stressed Areas

Source - news.bbc.co.uk

A large part of the world is experiencing stress on its water resources. Severely-stressed areas (red in the accompanying map) include Southwestern United States,  northern Mexico, Western and Eastern South America, vast portions of India, Northern China, much of Africa that surrounds the Sahara Desert, southern Africa and Australia (not shown)
Water stress, thus, is a fixture of both developed and developing countries
Water Stress in The Developing World

Boy Collecting Water
Source - sanakvo.org

In Asia and Africa, water stress is defined as lack of water for drinking and sanitation, both basic to human survival and good health.
This stress increases with income disparity for those in lower economic strata as the more affluent can get their water needs satisfied using their economic clout.
But even the affluent in the developing world suffer from water stress. Their stress arises from the ever-increasing water demand from production of goods and services that are the benchmarks defining someone as affluent.
Water Stress in The Developed World

Fountains in Las Vegas
Source -gothereguide.com

Water Recreation
Source - minneapolisparks.org

The inability to procure water needed to sustain economic growth and lifestyles is how water stress is defined in affluent countries.
Reducing Global Water Stress
So, it is difficult for all the world to agree on a common definition of water constitutes global water stress. And no globally supported effort can be defined and implemented to cut global water stress.The world's worsening water crisis, continues to further worsen.

Every Water Is Not The Same!

We all are quite familiar with the salty taste of ocean water compared to water deposited by rain and water streaming out of a faucet. Another difference may help us tap on-demand, the oldest freshwater source on Earth.
The Ocean in the Atmosphere
The hydrologic cycle maintains and continuously replenishes a vast ocean of freshwater in the air closest to the ground. This ocean is the source of all rain and snow, the dew we find deposited on our cars, dew deposited on the ground early in the morning and the moisture that appears on the outside of a cold glass. 
Isotope Hydrology

Change in isotope content during the hydrologic cycle
Source - ANTSO.gov.au

It is an established fact that water from different sources contains different number and types of isotopes.(see post dated Oct 15, 2011).
Isotope Hydrology is the new science that uses existence of isotopes to estimate age and origin of water in each stage of the hydrologic cycle.
What makes Isotope Hydrology most interesting is that it can map a "local" hydrologic condition to include an identification of the the origin and content of water in the local atmosphere.

Predicting & Catalyzing Precipitation
The primary cause of freshwater scarcity is continued lack of rain where and when we humans want and need it. Precipitation (mostly rain) directly waters our food crops, adds runoff to increase river flows and lake levels, and replenishes ground water reservoirs.
We could soon produce rain on-demand using Isotope Hydrology that can accurately measure the isotopic content of local air, compare it to conditions that produce rain and identify what changes are necessary to produce rain on demand anywhere on Earth!