'The real threat to our future is peak water'

[Lord Beria3]

http://www.guardian.co.uk/global-develo ... at-to-food

Peak oil has generated headlines in recent years, but the real threat to our future is peak water. There are substitutes for oil, but not for water. We can produce food without oil, but not without water.

We drink on average four quarts (4.5 litres) of water per day, in one form or another, but the food we eat each day requires 2,000 quarts of water to produce, or 500 times as much. Getting enough water to drink is relatively easy, but finding enough to produce the ever-growing quantities of grain the world consumes is another matter.

Grain consumed directly supplies nearly half of our calories. That consumed indirectly as meat, milk, and eggs supplies a large part of the remainder. Today roughly 40% of the world grain harvest comes from irrigated land. It thus comes as no surprise that irrigation expansion has played a central role in tripling the world grain harvest over the last six decades.

During the last half of the 20th century, the world's irrigated area expanded from 232m acres (93m hectares) in 1950 to 706m in 2000. This tripling of world irrigation within 50 years was historically unique. But since then the growth in irrigation has come to a near standstill, expanding only 9% between 2000 and 2010.

Farmers get their irrigation water either from rivers or from underground aquifers. Historically, beginning with the Sumerians some 6,000 years ago, irrigation water came from building dams across rivers, creating reservoirs that then enabled them to divert the water onto the land through a network of gravity-fed canals. This method of irrigation prevailed until the mid 20th century, but with few remaining sites for building dams the prospects for expanding surface irrigation faded. Farmers then turned to drilling wells to tap underground water resources.

In doing so, they learned that there are two types of aquifers: those that are replenishable through rainfall, which are in the majority, and those that consist of water laid down eons ago, and thus do not recharge. The latter, known as fossil aquifers, include two strategically important ones, the deep aquifer under the North China Plain and the Ogallala aquifer under the US Western Great Plains.

In looking at water and our future, we face many questions and few answers. Could the world be facing peak water? Or has it already peaked?

Tapping underground water resources, which got seriously underway in the mid-20th century, helped expand world food production, but as the demand for grain continued climbing the amount of water pumped continued to grow. Eventually the extraction of water began to exceed the recharge rate of aquifers from precipitation, and water tables began to fall. In effect, overpumping creates a water-based food bubble, one that will burst when the aquifer is depleted and the rate of pumping is necessarily reduced to the rate of recharge from precipitation.

Today some 18 countries, containing half the world's people, are overpumping their aquifers. Among these are the big three grain producers – China, India, and the United States – and several other populous countries, including Iran, Pakistan and Mexico.

During the last two decades, several of these countries have overpumped to the point that their aquifers are being depleted and their wells are going dry. They have passed not only peak water, but also peak grain production. Their aquifers are being depleted, their wells are going dry, and their grain harvests are shrinking. Among the countries whose use of water has peaked and begun to decline are Saudi Arabia, Syria, Iraq and Yemen. In these countries peak grain has followed peak water.

Nowhere are falling water tables and the shrinkage of irrigated agriculture more dramatic than in Saudi Arabia, a country as water-poor as it is oil-rich. After the Arab oil export embargo in 1975, the Saudis realised they were vulnerable to a counter-embargo on grain. To become self-sufficient in wheat, they developed a heavily subsidised irrigated agriculture based largely on pumping water from fossil aquifers.

After being self-sufficient in wheat for over 20 years, the Saudis announced in early 2008 that, with their aquifers largely depleted, they would reduce wheat planting by one-eighth each year until 2016, when production would end. By then Saudi Arabia projects it will be importing some 15m tons of wheat, rice, corn and barley to feed its Canada-sized population of 30 million. It is the first country to publicly project how aquifer depletion will shrink its grain harvest.

Syria, a country of 22 million people riddled by civil war, is also overpumping its underground water. Its grain production peaked in 2002 and during the decade since then has dropped 30%. It, too, is becoming heavily dependent on imported grain.

Grain production in neighbouring Iraq peaked in 2004. By 2012 it had dropped 33%, forcing the government to turn to the world market to feed its people. In addition to aquifer depletion, both Syria and Iraq are also suffering to a lesser degree from a reduced flow in the Tigris and Euphrates rivers, as upstream Turkey claims more water for its own use.

In Yemen, a nation of 23 million people that shares a long border with Saudi Arabia, the water table is falling by roughly 4ft a year as water use outstrips aquifer recharge. With one of the world's fastest-growing populations and with water tables falling everywhere, Yemen is fast becoming a hydrological basketcase. Grain production has fallen by half over the last 35 years. By 2015 irrigated fields will be a rarity and the country will be importing virtually all of its grain. Living on borrowed water and borrowed time, Yemen could disintegrate into an area of tribes warring over water.

Thus in the Arab Middle East the world is seeing the collision between population growth and water supply at the regional level. For the first time in history, grain production is dropping in a geographic region with nothing in sight to arrest the decline. Because of the failure of governments in the region to mesh population and water policies, each day now brings 10,000 more people to feed and less irrigation water with which to feed them.

Other countries with much larger populations, such as Iran, Pakistan and Mexico, are also near or beyond peak water. In Iran, a country with 81 million people, grain production dropped 10% between 2007 and 2012 as its irrigation wells started to go dry. One quarter of its current grain harvest is based on overpumping. With its population growing by over a million per year, it too faces a day of reckoning

A good article. I think you will find that the areas mentioned with extreme water issues will also dominates the headlines in terms of wars, instability and famine in the coming decades to come.

[kenneal - lagger]

My daughter did a thesis on water shortages and wars ten years ago. It's been known about but like so many things to do with economics it's been ignored because "the market will find a solution." This is just another failure of our system of economic theory (I won't call it a science because it isn't one).

The UK's economic system is failing in this area too as it is failing to put a price on development in the South East which takes into account the provision of sufficient water. There is less water per person available in the south east than in the Lebanon and several other countries in that area. Any development in the south east should have a huge premium attached to pay for future water supplies. This might drive development, both industrial and residential, further north and west where there is sufficient water.

[biffvernon]

Peak oil has generated headlines in recent years, but the real threat to our future is peak water.

I don't know why people start articles with sentences as stupid as that. It puts me off reading the rest.

Oil is a finite resource that gets used up and it's production rate has to peak.

Water is constantly recycled through a giant purification system and global warming actually results in a faster throughput.

Of course there are local dry spots and climate change may cause some of these to shift, which is inconvenient, and human demand for greater throughput is a further local problem.

Ken, your comment comparing South-East England with Lebanon omits the overriding factor of evaporation rates. South-East England is a much wetter place, despite it's comparatively low rainfall.

[frank_begbie]

Fracking is only making things worse.

We just can't let go of trying to carry on with business as usual.

[vtsnowedin]

If you look at the water situation in Iran then any water shortage in the UK becomes trivial.
http://www.ncr-iran.org/en/news/society ... risis.html

[adam2]

Yes, oil once used is for all practical purposes gone forever.
Water is endlessly reusable and can be purified either naturaly by the water cycle, or by man made means.

Some very arid countries are arguably unfitted to the present population densities because they cant produce enough food.

Desalination equipment is now cheaper and better than ever, but still unlikely to make large scale irrigation viable.

Many places that suffer from drought are also liable to flooding, suggesting that lack of storage rather than lack of rain is the problem, in some places.

[kenneal - lagger]

The fossil water used in many highly populated places is as irreplaceable as oil. Saudi Arabia may have seen the light and be able to replace its home grown, fossil water irrigated wheat with bought in wheat paid for by it's current oil wealth but places like the Punjab in India where population has rocketed on the back of oil based fertilizers and fossil water will see mass emigration or starvation when the fossil water that they have been using for irrigation dries up or becomes too saline soon.

Biff might be happy to welcome them all to Lincolnshire but I don't think that his neighbours will be so accommodating. The Punjab is just one such highly populated food growing area that will be affected, as has been pointed out earlier in the thread, so the mass starvation or mass migration will make current migrations look minuscule. People can put up with economic hardship much more than food and water hardship.

[UndercoverElephant]

If you look at the water situation in Iran then any water shortage in the UK becomes trivial.
http://www.ncr-iran.org/en/news/society ... risis.html

Yes and no.

Yes, it's trivial when you consider how much rainfall we have in the UK. But this comes with three caveats. The first is that the rainfall in the UK is very unpredictable, so we never know from year to year whether it isn't going to stop raining, or the sun won't stop shining. The second is that the rainfall is, on average, not very evenly distributed - the west gets drowned and the east doesn't, especially the southeast. The third, and probably the most serious, is that our infrastructure is ancient. Just as is the case with the London Underground, the fact that we were the first nation to build a proper water supply/treatment system means that ours is the oldest, and leakiest. And much of it is very expensive to replace, especially in built up areas. That's the real problem in the UK - in some parts of the country less than half of the water that leaves the treatment plant actually arrives at the consumer's tap.

[RenewableCandy]

The Met Office rainfall map shows the Western Isles get 8 times the rainfall of the SE of England. That's a heck of a difference. The Chair of Anglia Water cheerfully informed the public that there are large parts of Israel which get more rainfall than East Anglia. The SE is too densely populated to make room for large clever pieces of water-related infrastructure, and so here we are.

On days like this, go meat-free, and get a water-barrel

[woodburner]

The Punjab is just one such highly populated food growing area that will be affected, as has been pointed out earlier in the thread, so the mass starvation or mass migration will make current migrations look minuscule. People can put up with economic hardship much more than food and water hardship.

No problem with food, my MP says that GM will produce higher yeilds with less fertiliser be more disease resistant and being less prone to damaging weather. So that's sorted.

[RenewableCandy]

It is highly probable that your MP and Jack Schitt know each other

[biffvernon]

The Met Office rainfall map shows the Western Isles get 8 times the rainfall of the SE of England. That's a heck of a difference.

Which map is that? I don't think it can be this one. (The Western Isles have been left out!) You might get a x8 factor on certain Cumbrian slopes, but that hardly counts. It might be fair to say that the western mountains are twice as wet as eastern England.



By a convenient quirk of geology, the wetter west tends to have impermeable rocks, off which the rain slips quickly to the sea, while the east tends to have porous rocks whose sponge-like properties even out the flows with massive natural storage.

And let's not run away with the weather variability without looking at the actual data. What, for instance, was the rainfall in the wettest and driest years, if we want to start with extremes?

[JavaScriptDonkey]

Water is constantly recycled through a giant purification system and global warming actually results in a faster throughput.

I'm surprised you haven't stumbled across the concept of fossil water Biff.

It's been a bit if a thing in some periodicals.

The short version is that they are water reserves that are not going to refill anytime soon.

A bit like CO2 in fossil fuel only with water vapour.

I wonder what the implications might be?

[biffvernon]

I studied hydrology at university. Not sure whether that counts as stumbling across a concept.

For sure, there are local difficulties, and making farming rely on small, non-replenishing aquifers is short-sighted and ultimately doomed.

But in the grand scheme of things such 'fossil' waters represent a very small part of the water that humanity makes use.

In my own part of the world, on the yellow bit of the map above, the main problem is getting rid of excess rainwater, ensuring that it can get to the sea as soon possible.

[clv101]

But in the grand scheme of things such 'fossil' waters represent a very small part of the water that humanity makes use.

In my own part of the world...

This is the problem and where analogies with 'peak oil' struggle. Because of oil's fungible nature the oil situation is a global situation. Water is the exact opposite - it all local/regional.

The reality is that a vast number of people do live in water stressed areas, population in many of these areas are increasing and available water supply decreasing. Fossil water is irrigating a high proportion of food supplies in some regions, glacial melt water provides a huge amount of water in China and India. Deforestation is weakening the hydrological cycle and it's likely that monsoon rains will shift in a changing climate. Increased urbanisation and industrial activity is also creating localised areas of high demand.

Maybe the good folk of Lincolnshire won't face water shortage any time soon, but I fully expect water stress to become a much bigger problem than it already is for several billion people before this century's out.