Freshwater Innovations Fuel Population Growth!

While we may never know with absolute certainty the answer to the question: "Which came first, the chicken or the egg?" we can be reasonably sure that human population grew and thrived because required amounts of freshwater became available necessary to sustain growing numbers of people.
Human Population Growth

Source - Adapted from Page 15, of book titled
"Pandora's Seed" authored by Spencer Wells

Approximately 200,000 years ago, our breed of human (aka Homo Sapiens) originated in Africa. Only 60,000 years ago Homo Sapiens started to grow in number.
Some 10,000 years ago, however, this rate of growth accelerated dramatically - Human population grew thousand-fold, from 1 million people to 1 billion people, in less than 10,000 years. 
Role of Freshwater

Source - Ommato LLC

When key water-related innovations are superimposed on to the population graph, it becomes clear how these innovations influenced growth in numbers of people. Key water-related innovations included:
- About 10,000 years ago, humans dug a well to capture water they saw disappearing into the ground
- Some 7,000 years ago, irrigation was born when humans figured out that water would, on its own accord, move from higher levels to lower levels
- About 5,000 years ago humans made the artificial lake when they built a dam to stop a river from flowing
- Approx 4,000 years ago humans began to raise water from lower levels to higher levels with the invention of a Shaduf. This was quickly followed with the Archimedes Screw and the Waterwheel all increasing the height to which water could be raised.
- Around 300 AD, 1900 years ago, the Romans built their gigantic aqueducts to bring water from many miles away to their cities.

Impact of Innovations
Each innovation had its incremental impact. But as is evident from the chart, the greatest impact on human population numbers came from the inventions that raised water to very high levels and that transported water over long distances.

What innovations lie in the wings or are possible today, that will bring abundance to safe drinking water in the 21st century?

Small Numbers and Water Sufficiency!

Small numbers, like everything else, when looked at without a framing context have no meaning at all and usually lead to the wrong conclusion. The oft-repeated statement "Only 2.5% of the water on Earth is freshwater" is factually correct considering the measurements and assumptions behind its quantification. But is it correct in implying that because 2.5% is a small number, it only represents a problem?
Lumps of Sugar

Source - blog.cytalk.com

If the question is: Are 2 lumps of sugar more than enough to feed all the ants in the world or would 600 lumps of sugar be adequate?

Source - twobitbard.weebly.com

The likely answer usually is: 600 lumps.
The primary reasoning behind this answer is the assumption that as 600 is more than 2, then 600 is likely to NOT be the wrong answer. And, as the convoluted logic goes, if it is less likely to be the wrong answer, then, of course, it is more likely to be right answer.

Source - clker.com

The other bits of assumption are what we know about how much sugar an ant requires and the actual size of each lump of sugar! And as we do not precisely know these bits of information, we go with the larger number i.e. 600 lumps while assuming the size of each sugar lump based on how large we think the spoon is. This spoon size is based on the spoons we usually use.
But what if each lump was 1kilometer long on each edge? And there were 150 Trillion ants in the world? Then too the larger number would be the answer, because the number is simply larger. Going with the larger number of 600 lumps is just safer because it is less likely to be wrong.
This logic applies also to freshwater supplies
Only 2.5% of the Earth's Water is Freshwater

Source - go.water.usgs.gov

What is the conclusion when we see the world's water (larger blue sphere) and freshwater in liquid form (smaller blue sphere), displayed relative to the size of the Earth? 
The 1st conclusion: We have very little water and even less liquid freshwater! (relative to the size of the Earth, of course)
The 2nd conclusion: We could quickly run out of freshwater! ... because see how little of it exists in comparison with the size of the Earth.
But what's our conclusion when we know the following:
The total amount of water on Earth is: 
- About 332,500,000 cubic miles (mi³) = 1,386,000,000 cubic kilometers (km³)
- The larger sphere is about 860 miles (about 1,385 kilometers) in diameter
The amount of Freshwater
If 2.5% of the total water is Freshwater, then the amount of freshwater is: 8,312,500 cubic miles (mi³) = 3,465,000 cubic kilometers (km³)
The size of these numbers makes it very difficult to reach a conclusion one way or another! Even conceptualizing how large (or small) a cubic mile is, is difficult for most of us.
The Takeaway
Small percentages do not necessarily imply insufficiency or sufficiency.
Much more analysis is required before we can judge if we are facing freshwater insufficiency or insecurity anytime in the near or far future.

The Energy-Freshwater Nexus

Humanity has created an inter-dependency between water and energy that would be impossible to take apart. The most recent example of this inter-dependency are the recent blackouts in India.
600+ million people without electricity

Auto traffic at a standstill
Source - geekosystem.com

Candle light for a haircut
Source - theaustralian.com.au

While the causes of the blackouts of July 2012 are still being determined, a root cause has been suggested: "... northern states may have been drawing more than their allocated power quota to help stricken farmers pump groundwater from bore wells ..." (The Financial Times dated 30 July 2012).  This large and unprecedented demand for ground water was fueled by a large monsoon deficit.
Hydropower

Tehri Hydroelectric Power station - India's largest
Source - wikipedia.org

Freshwater is also the fuel for 19% of India's electric power supply.
As in most parts of the world, the first electric power generating station in India was also a hydroelectric station commissioned in 1897.
This nearly one-fifth of India's electricity generating capacity requires reservoirs of freshwater which, in July 2012, dropped to just 24% of their capacity.


Water Consumption for Different Energy Fuels

Source - World Economic Forum

• Minimal water is consumed in production of traditional oil and gas resources - 3 to 7 liters/GJ   (GJ=gigajoule)
• Enhanced oil recovery require 50-9000 liters/GJ
• Oil sands require 70-1,800 liters/GJ
• Petroleum refining requires 25-65 liters/GJ
• Unconventional gas resources require 36-56 liters/GJ
• Corn grown for bio-fuels require 9,000-100,000 liters/GJ
• Soy grown for bio-fuels require 50,000 - 270,000 liters/GJ
• Coal mining requires 5-75 liters/GJ
• etc

Energy production is water-intensive just like water production is now energy-intensive