'The real threat to our future is peak water'

[adam2]

The other problem is that at present it seems fashionable to "not do maths" which leads to unrealistic claims and suggestions as to what should be done to relieve water shortages.

For example it is fairly regularly proposed that water be transported frrom the wetter regions of the UK to the dryer ones, either by pipeline or by road or rail.
In most cases, the volumes innvolved and costs in energy/money render the idea a non starter. "if they can transport petrol by tanker from Wales to London, why cant they transport water" Well you could, but the price would too high. (rail transport might be viable in an emergency)
Because those who propose this "dont do math" they cant see that the cost of transporting the water would be many times the current price.

Likewise desalination is frequently proposed as the answer to everything. This technology has recently much improved and is increasingly viable for supplying relatively modest volumes per head for cities lacking other water sources.
I cant see desalinated sea water EVER being viable for the bulk production of relatively low price commodity crops such as wheat.

A modern desalination plant can produce drinking water for a few dollars a ton, viable for domestic use, light industry, and for the affluent to water their lawns (if someone earns $250,000 a year, I doubt if they care if watering the lawn costs $10, or $100, the gardeners wages would be far more)

But irrigating a million acres of wheat at that price ?

[biffvernon]

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.

Oh yes, that's for sure. I was talking yesterday to some friends just back from India. They were caught up in the recent flood chaos and were air-lifted out after all river bridges were swept away. The monsoon arrived earlier than expected and a sudden excess melt of snow combined with deforestation and some poor real-time flood management decisions to cause a humanitarian disaster, with the hapless English tourists as bystanders. Another significant problem they recounted is that the area has sensible planning laws about where one may and may not build on the flood plains but these laws have been mediated through bribes such that a lot of houses have been built illegally. This causes certain 'tensions' when the house is swept away in a deluge and an official, with bulging back pocket, is asked to account for the losses.

It's going to be very difficult to forecast the future. Global warming means more rapid melt of old glacier ice providing more water, but in short sudden bursts just when it isn't needed, and then, when it's gone it's gone. But then global warming means more water in the air and that means more rain, probably in sudden bursts just when it isn't needed.

But it is all local, requiring local solutions. I have another friend who is working on setting up an organic farm in Ghana. He was showing me the first stage of the work - lots of digging to create massive drains fed by a dense system of ditches leading to a big reservoir and a system of irrigation channels to send the water back to where it was needed. There is plenty of rain in this area but it tends to come in short sudden bursts just when it isn't needed. The solution is not rocket science but the same water management techniques that have been used for a couple of millennia.

Very often, in many parts of the world, the solution to the water problem involves a lot of manual labour, small reservoirs, collection and distribution ditches and compost. Small scale, organic, farming, with good management of whatever the skies throw down, supplying local demand is likely to increase both employment and food yields. Industrial agrochemical farming for export of cash crops tends to be part of the problem rather than part of the solution.

Wringing one's hands in despair over 'the water crisis' is probably counter-productive.

BTW, I read somewhere that the Syrian situation was in part triggered by disputes over access to water. Anyone know owt about that? Maybe the current civil war may come to be written as a water-war, the various religious differences being convenient scapegoats.

[PS_RalphW]

The world is littered with massive irigation systems where ancient civilisations flourished for centuries before climate change or resource limits caused them to dry up or fall into disrepair. Usually ditches and a few temples are all that remains visible in the jungle or dessert.

The climate is changing fast. Rain today is no guarantee of rain tomorrow.

[edit]

The BBC documentary by Dan Snow reported a 10 year drought in Syria, maybe related to climate change in Syria, combined with falling oil production and rapidly rising population meant that the ruling party could no longer keep food prices in check with enough subsidies.

The old story. Same as Egypt, Yemen and quite a few more.

[biffvernon]

The climate is changing fast. Rain today is no guarantee of rain tomorrow.

The climate is changing but, on average, it will rain more tomorrow.

The trouble with averages is that some folk are living on the wrong side of the mean or too far from the mean.

[Little John]

The climate is changing fast. Rain today is no guarantee of rain tomorrow.

The climate is changing but, on average, it will rain more tomorrow.

The trouble with averages is that some folk are living on the wrong side of the mean or too far from the mean.

I think those deviations from the mean may turn out to be catastrophic for most people.

For example, a hotter world may produce more rain on average. But, this could mean perpetual floods for half of the world and perpetual droughts for the other half.

[kenneal - lagger]

..........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.

Central China, Central USA (the Ogalala aquifer) and the Punjab rely on fossil water at the moment and pumped water in the Punjab is becoming saline already. There's your several billion.

[biffvernon]

I think those deviations from the mean may turn out to be catastrophic for most people.

Which is why, all things considered, putting greenhouse gasses into the air was a pretty dumb thing to start doing and and even dumber thing to continue with now that we all know what the result will be.

[kenneal - lagger]

I don't think that anyone is denying that, Biff.

[biffvernon]

I don't think that anyone is denying that, Biff.

Er, how about our government? Oh, you mean on this forum

[RenewableCandy]

Annual rainfall map, UK. The scale itself has a factor of 5, the extremes will be more than that.

There is an alive proposal to link Scotland and the SE by linking already-present canals, enabling irrigation water to be moved around to where it is most needed. Looking at that map, I can see the sense of such a project.

[woodburner]

The flow rate would be s fast, no boats could use the canal

[biffvernon]

Annual rainfall map, UK. The scale itself has a factor of 5, the extremes will be more than that.

But almost all of Britain, (lets ignore Snowdon, Hellvelyn, Ben Nevis and a bit of Essex) is within a factor of 2. The extremes really don't make for a good description of a land.

[UndercoverElephant]

The flow rate would be s fast, no boats could use the canal

Yeah, right. Rapids!

Boats would be able to use the canal just fine. The existing canal network is already used to transport water around, most notably the Llangollen, which brings water down from the upper reaches of the River Dee to a reservoir at Hurleston. This flow makes a significant difference to the speed it takes to go up the canal compared to the other way, but most of this time loss happens is you try to get through the narrow bridges, because the water flows much faster here. The normal speed limit on a canal is 4mph, and the reason is to prevent breaking waves in the wash from damaging the banks. But if you put a narrowboat on a river instead, and go at full pelt, it can easily do three times that speed. So the flow rate on the canal would have to exceed 10mph before it would become unusable even for existing narrowboats designed for canals with 4mph speed limits. The flow rate on the Llangollen does not usually exceed 2mph.

[biffvernon]

Annual rainfall map, UK.

I've just noticed a neat feature of the map at http://www.metoffice.gov.uk/climate/uk/ ... pavge.html
If you toggle between the Averaging Period (bottom box on the left hand options menu) you can see how Britain has been getting wetter.

Yeah, ok, one swallow doesn't make a summer...

[RenewableCandy]

Yeah I noticed that too. Try it with "Temperature": it's even worse!

I can see your point, but the extremes also include a bit of London, and Glasgow. In other words, quite a lot of people.