Water: Where will it come from in 2050?

[Zythryn]

Originally Posted by Michaelangelica

Water authorities in south-east Queensland have calculated evaporation losses are equal to the annual consumption of 1.6 million households.

Very interesting. First thing I would check though is does the evaporated water come back to earth as rain in an area desperate for water?
They could be saving water in one spot and not allowing it to fall on farmland

[Michaelangelica]

I agree Tecnology will help but we need to start thinking about the problem now

What's gone wrong?

As our world heats up, as pollution increases, as population grows and as our globe's resources of fresh water are tapped, we are faced with an environmental and humanitarian problem of mammoth proportions.

Demand for water is doubling every 20 years, outpacing population growth twice as fast. Currently 1.3 billion people don't have access to clean water and 2.5 billion lack proper sewage and sanitation. In less than 20 years, it is estimated that demand for fresh water will exceed the world's supply by over 50 percent.

The biggest drain on our water sources is agriculture, which accounts for 70 percent of the water used worldwide -- much of which is subsidized in the industrial world, providing little incentive for agribusiness to use conservation measures or less water-intensive crops.
. . .
. . .
Some see technology as the necessary fix -- or at least a step in the right direction. As the BBC reports:

New technology can help, however, especially by cleaning up pollution and so making more water useable, and in agriculture, where water use can be made far more efficient. Drought-resistant plants can also help.

Drip irrigation drastically cuts the amount of water needed, low-pressure sprinklers are an improvement, and even building simple earth walls to trap rainfall is helpful.

Some countries are now treating waste water so that it can be used -- and drunk -- several times over.

Desalinization makes sea water available, but takes huge quantities of energy and leaves vast amounts of brine.

But many warn against relying on a "techno-fix" to solve our problems.

AlterNet: Environment: Our Drinkable Water Supply Is Vanishing

This seems like an interesting idea.
Linking the de-humidifiers (see previous posts) with afree energy source. Sound ideal as long as you have some wind

The windmill that produces water out of air
His solution is an innovative windmill which, unlike the conventional three blades, has several blades arranged around a vertical column that can take wind from any direction.

The secret lies in a cooling process kicked off by the blades which propel the air into a "chiller" box where water molecules condense on specially designed plates.

Whisson points to ancient tribes in the area that is now Ukraine who used pyramid-shaped rock structures to cool air and produce their water.

The design of his collection plates was also assisted by analysing the body of a beetle that has adapted to its harsh desert environment in Namibia.

The beetle gets drinking water from fog which condenses on its back before trickling down to its mouth.

That provided the inspiration for fog-harvesting nets used in arid mountainous areas of Africa, South America and Asia, but Whisson believes his design has bigger potential.

Wind powers not only the blades, but also the refrigeration process. Although water can be produced in a breeze as gentle as 2km/h, stronger winds generate more power and therefore water. Even better, the hotter the temperature, the more water the air contains.

IOL: The windmill that produces water out of air

More here
WATER UN LIMITED - Potentially the world's first continuous source of water
Max Water News

30.05.07: The Max Water features on the 'saving water special' on ABC's 'The New Inventors'

22.05.07: Fantastic ABC 'Australian Story' documentary on inventor Max Whisson

15.03.07: Alternative Energy Sources online article

[Michaelangelica]

Air water harvesters Could have an important role reducing the greenhouse gas H2O too.
We could kill two birds with the one stone.

Earth getting steamier and steamier

Michael Kahn
Reuters
Thursday, 11 October 2007

raindrops
Warmer air holds more water vapour, a greenhouse that stokes the warming effect and so worsens humidity (Image: iStockphoto)
Greenhouse gases are making the earth's atmosphere wetter and stickier, which may lead to more powerful hurricanes, hotter temperatures and heavier rainfall in tropical regions, UK researchers report.

The findings, published today in the journal Nature, are some of the first to suggest how human-produced greenhouse gases have affected global humidity levels in recent decades.

The results could also offer clues on future climate change, the researchers say.

News in Science - Earth getting steamier and steamier - 11/10/2007

Could this technology be combined with air conditioning for domestic use?

the Air Water Pty Ltd's Air Water Machines also harvest water from air by using a condensation method. An example of the principle is the water you see on the ground under your car's air-conditioner, or the water in the bottom of your fridge: water from air!

These machines "pull air over a condenser, chill it and harvest the resulting water." Simple! Why did I not think of that!

This company's "Lifesaver" machine is the world’s first unique PV Solar Powered system that stands alone, in any place, 24/7, while producing huge amounts of water. The Lifesaver can provide water and power independence practically anywhere.

It produces 500 litres of water in 24 hours. It needs input power of 8.8KW and consumes 0.4kwH per litre of water produced.

See it in action here but make sure you enable your Firefox browser to play it, or use Internet Explorer.

It sells many different types of water from air harvesters,ranging from domestic use to that of a village!

The "Villager" produces 1000 litres per day (264 gallons) and the "Irrigator" an impressive 5000 litres (1321 gallons). At an estimated AUS 3c cents per litre this is still costly if using a diesel generator. But with wind or solar...

Water From Air - Using Salt
also more at
Conjuring Water From The Air | Robin Bloor

PS
from India

For more information on GE Water & Process Technologies, visit Water & Process Technologies: Water, wastewater and process systems solutions.

GE to Supply ecomagination Products for Dynoil's Alternative Energy Initiative
I wonder what a unit would cost?

More info here. very interesting

Electrodialysis Reversal (EDR)

Electrodialysis Reversal (EDR) is an electrochemical separation process that removes ions and other charged species from water and other fluids.

EDR uses small quantities of electricity to transport these species through membranes composed of ion exchange material to create a separate purified and concentrated stream.

Electrodialysis Reversal (EDR)

[Michaelangelica]

I would like someone to invent for me a domestic air water harvester, combined with a (preferably solar powered) air conditioner.
Any takers?
Any info on the WWW?

[freeztar]

They're called dehumidifiers and they have been around for a long time.
Dehumidifier - Wikipedia, the free encyclopedia

Here are some models for sale:
Dehumidifier, Heating, Cooling Air, Industrial Supply, MRO items on eBay.com

SolarVenti SV2 SOLAR VENTILATION DEHUMIDIFIER HEATER SS - (eBay item 110176028037 end time Oct-30-07 16:50:25 PDT)

[HydrogenBond]

The best natural source of clean water is already setting itself up. It is called global warming. If the earth gets warmer, that means more water from the oceans will evaporate and end up in the atmosphere. This means the amount of drinking water produced by the sun will increase. The bigger storms are a good way to water down the poluted inland water so it can flow to the oceans for recycle. The water table is also replenished so the future will have a larger reservoir of good drinking water.

The warmer temperatures and the higher supply of rain water, then means that the plants will see a longer growing season and will be able to cover a larger percent of the earth's land. Plants help to fix water, so it can not evaporate as easily. Beside more fresh water, global warming by stimulating plant growth, will create more food. The fear of global warming is for the short term inconvenience, not the longer term benefits.

[Erasmus00]

Originally Posted by HydrogenBond

The warmer temperatures and the higher supply of rain water, then means that the plants will see a longer growing season and will be able to cover a larger percent of the earth's land. Plants help to fix water, so it can not evaporate as easily. Beside more fresh water, global warming by stimulating plant growth, will create more food. The fear of global warming is for the short term inconvenience, not the longer term benefits.

Not really true, as far as food goes. Warming shifts the ideal growing latitude away from the equator, where much of the land is not suitable for farming (no topsoil). Less food, not more.
-Will

[freeztar]

Originally Posted by HydrogenBond

The best natural source of clean water is already setting itself up. It is called global warming. If the earth gets warmer, that means more water from the oceans will evaporate and end up in the atmosphere. This means the amount of drinking water produced by the sun will increase. The bigger storms are a good way to water down the poluted inland water so it can flow to the oceans for recycle. The water table is also replenished so the future will have a larger reservoir of good drinking water.

It's important to note the difference between GW and climate change. Climate change allows for variability of climate locally. For example, areas that were once forests, might dry up to deserts and then flooding might occur elsewhere.

The warmer temperatures and the higher supply of rain water, then means that the plants will see a longer growing season and will be able to cover a larger percent of the earth's land. Plants help to fix water, so it can not evaporate as easily.

Plants do not help fix water. They do the opposite. Through a process known as transpiration (often combined with evaporation to become evapotranspiration), the plants make very efficient water producers effectively syphoning the moisture from the ground and releasing it into the air.

An acre of corn gives off about 3,000-4,000 gallons (11,400-15,100 liters) of water each day, and a large oak tree can transpire 40,000 gallons (151,000 liters) per year.

The Water Cycle: Evapotranspiration, from USGS Water Science for Schools

Beside more fresh water, global warming by stimulating plant growth, will create more food. The fear of global warming is for the short term inconvenience, not the longer term benefits.

On the global level, I think there will be far less fresh water available if we continue to see a climate shift with a warming trend (we already are). And as Erasmus pointed out, a warming trend would narrow the growing range for many crops.

[Cedars]

Originally Posted by Erasmus00

Not really true, as far as food goes. Warming shifts the ideal growing latitude away from the equator, where much of the land is not suitable for farming (no topsoil). Less food, not more.
-Will

I have always been under the impression much of the equatorial regions have very poor soils, such as the amazon area where farmland is basically useless (without huge amounts of ferts) after only a few years.

Global soil orders map:
http://www.in.nrcs.usda.gov/mlra11/i...ers_poster.JPG

As I understand good crop soils, the map above indicates these regions are shown in the greens (with some variables of course).

Much of the success of current crops is because of hybrid seeds allowing crops to be grown in regions whos climate doesnt support them currently, such as corn that ears out in 90 days rather than 120, dwarf wheats (which dont topple over in the winds) wheats with shorter growing seasons allowing second crops, etc. A longer growing season (warmer conditions) will increase the amount of lands that can support crops simply due to the massive amount of land which is too cold to farm our typical food crops.

[Cedars]

Originally Posted by HydrogenBond

The water table is also replenished so the future will have a larger reservoir of good drinking water.

The water table needs sitting water to be able to soak down into the ground. With the massive drainage of wetlands that comes with development, I dont see any potential for increased reservoirs under the surface. Just more waters running back into the oceans.