Desalinering, fattigdom og hvete

... hva koster desalinering nå for tiden? Vi holder oss til Australia i første omgang. I følge New York Times ligger kostnaden der et sted mellom 1 og 2 dollar per kubikkmeter:

Mr. Young of the Water Services Association said desalination in Australia costs $1.75 to $2 per cubic meter, including the costs of construction, clean energy and production. The prices are probably the world’s highest, said Mr. Pankratz of the International Desalination Association, adding that desalination was cheaper in countries with less strict environmental standards. He said the cost at a typical new plant in the world today would be about $1 per cubic meter.

(Arid Australia Sips Seawater, but at a Cost; NYT, juli 2010)

Dette må vel tolkes dithen at kostnaden for bygging og drift med kullkraft-strøm (Australias hovedkilde) og uten å gjøre noe særlig for å beskytte miljøet mot det konsentrerte saltvannet som er et biprodukt er ca 1 dollar, mens å produsere med fornybar energi og ansvarlig håndtering av avfall opp mot dobler prisen.

Fra CSIRO (den australske offentlige vitenskapsorganisasjonen) finner vi Desalination in Australia (Hoang et al, februar 2009, PDF!). Der står det mye interessant, blant annet at

The product water cost per kL is mostly in the range of less than $1.25 for potable water and $1.25-$2.00 for industrial water. The higher cost for industrial water can probably be attributed to the lower plant capacity and lack of economy of scale. In addition, the cost of supply to industrial customers is generally higher as a result of the shorter capital recovery period for industrial projects compared with municipal projects.

(s. 5)

The survey data show that the average energy consumption is 3-3.7 kWh/kL for sea water RO, 0.7-1 kWh/kL for brackish water and 1.2 kWh/kL for industrial effluent.

(s. 9)

og så har de denne fine tabellen over internasjonale kostnader:

(Hva er det israelerne gjør? Are they just that good?)

Om det er US eller Aus dollar spiller liten rolle for vårt formål, kursene er iflg Norges Bank nå hhv ca 5,5 og 5,8 kroner, vi runder med god samvittighet opp til 6; og med et stadion-estimat på 1$ per kubikkmeter/kiloLiter ender vi opp med 6 tidels øre pr liter for avsalting.

Så for australiere, som er rike i global sammenheng, er kostnaden nærmest neglisjerbar: 200 liter per pers per dag koster ikke mer enn 1 krone og 20 øre (per person og dag).

Det ser nokså annerledes ut for verdens fattige. I følge o store Wikipedia, så

The World Bank defines extreme poverty as living on less than US $1.25 (PPP) per day, and moderate poverty as less than $2 a day (but note that a person or family with access to subsistence resources, e.g. subsistence farmers, may have a low cash income without a correspondingly low standard of living - they are not living "on" their cash income but using it as a top up). It estimates that "in 2001, 1.1 billion people had consumption levels below $1 a day and 2.7 billion lived on less than $2 a day."

(Jeg må jo si at jeg stiller spørsmålstegn ved å gjøre et sånt estimat uten å prøve å sette en pengeverdi på utbyttet fra subsistence farming, men men)

Og fra FAO:

A good yield of wheat under irrigation is 4 to 6 ton/ha (12 to 15 percent moisture). The water utilization efficiency for harvested yield (Ey) for grain is about 0.8 to 1.0 kg/m³.

(Wheat - versjon 2002)

og også

Under irrigation a good commercial grain yield is 6 to 9 ton/ha (10 to 13 percent moisture). The water utilization efficiency for harvested yield (Ey) for grain varies then between 0.8 and 1.6 kg/m³.

(Crop Water Information: Wheat)

Ser ut til å være to forskjellige versjoner av samme artikkel; den første er eksplisitt Last update: 16 October 2002, mens den andre sier bare "Copyright FAO 2011" -- men det er bare en arv fra nettside-templaten, og sier ingenting om når artikkelen ble skrevet. Men den siste er nok nyere. Fra 1,0 til 1,6 kg/kl maks "vannavkastning" er ganske enormt! Og det er bevegelsen fra 4-6 til 6-9 tonn/ha også. Men så er formuleringen i den første "a good yield of wheat", mens den andre er "a good commercial grain yield" (min utheving), så det er mulig at det er en epler-og-appelsiner -- sammenligning her: at den første snakker om hva som er vanlig på verdensbasis, den andre snakker om hva de største industridyrkerne oppnår. All den tid FAO ikke oppgir noen middel- eller medianverdi eller sier noe mer kan vi bare gjette.

Og siden vi først er i gang med stadionestimater så stadionestimerer vi at det går med en kubikkmeter vann til ett kilo hvete.

Dersom alt dette vannet skulle bringes til veie ved desalinering -- si hvis vi ville dyrke hvete i ørkenen i Australia (ja det høres perverst ut, men jeg har i vinter og vår kunnet kjøpe billige poteter fra Saudi Arabia(!) i Norge (!!!)) --
så ville desalineringskostnaden utgjøre ca 6 kr/kg.

Dette er direkte sammenlignbart med prisen for en kilo hvetemel, en detail, i Norge i dag.

Hvis vi antar at produksjonskostnaden er ca. en fjerdedel av butikkprisen, så innebærer det en kostnadsøkning på 300% eller deromkring.

Og de som lever på 2 dollar dagen som ikke er sjølvergingsbønder vil være ettertrykkelig priset ut av markedet.

Staniford om mat

Stuart Staniford kommenterer på Food Security: The Challenge of Feeding 9 Billion People.

Jeg hadde skannet den noen dager før og funnet den uinteressant -- den er holdt i svært generelle termer, så generelle at det hele blir nærmest meningsløst. Men Stanifords kommentarer er interessante; det er også hans to år gamle TOD-essay The Fallacy of Reversibility (som han linker til i en kommentar).

"Food Security:..." refererer til Forecasting Agriculturally Driven Global Environmental Change (Science / Tilman et al.)
som har litt mer kjøtt på beina...

During the first 35 years of the Green Revolution, global grain production doubled, greatly reducing food shortages, but at high environmental cost (1-5). In addition to its effects on greenhouse gases (1, 6, 7), agriculture affects ecosystems by the use and release of limiting resources that influence ecosystem functioning (nitrogen, phosphorus, and water), release of pesticides, and conversion of natural ecosystems to agriculture. These sources of global change may rival climate change in environmental and societal impacts (2, 8). Population size and per capita consumption are assumed to be the two greatest drivers of global environmental change. Humans currently appropriate more than a third of the production of terrestrial ecosystems and about half of usable freshwaters, have doubled terrestrial nitrogen supply and phosphorus liberation, have manufactured and released globally significant quantities of pesticides, and have initiated a major extinction event (2-4, 8-10).

.

Vi må frykte mer

Enda et bra skriv fra Michael Lardelli: Peak Oil means Peak Food as well

I am pessimistic about the future because I have seen and understood the data on resources. I know that oil production peaked in July 2008. (I have seen the unpublished reanalysis of the International Energy Agency's own 2008 report that shows this conclusively.) I know that our use of other resources - such as water and phosphate - is critically unsustainable. Now that energy is declining there will not be enough to invest in building the alternative energy future that many of us dream of.

The nature of our economic/political system means that the declining fossil energy supply will go to the shorter term priorities of growing food, supporting armies and maintaining (as far as possible) the comfortable lifestyles of an ever-contracting circle of the wealthy. The time needed to build any form of alternative energy infrastructure - and the scale of the expansion needed in the face of the current and worsening energy decline - mean that it will simply never happen.

If I am so pessimistic, why do I bother writing about it? What good does it do? As a scientist I know that you must understand a problem in order to solve it. To have any chance of coping with this developing disaster we need to see it for what it truly is - not pretend that it does not exist (for example, the population problem) or that it will never happen (for example, peak oil). If we do not understand the true nature of the problem the "solutions" we attempt may make the problem worse. Like supporting future population growth through more efficient use of resources. Or growing biofuels on marginal land without considering how you will replace the soil nutrients they deplete. Or planning to electrify of the car fleet without considering the load that will place on an overstretched grid or where the energy and materials will come from to maintain the road network it requires.

[...]

"Optimism" is the problem, not the solution. We use it as an excuse to avoid thinking about the desperate measures we must take to cope with what is coming. We use it to put off actually doing anything. As long as Dr X, CEO Y or Minister Z says, "I'm optimistic that we will develop new energy sources" then we can go back to sleep because someone is obviously taking care of the problem - aren't they?

[...]

Today we are often told we need a new "Manhattan Project" for alternative energy but we will never make the sacrifices necessary for this in our already worsening economic situation if we are not truly, deeply fearful of the consequences of failure. Only fear - not optimism - can motivate populations sufficiently when they are already struggling with rising food prices, falling incomes and unemployment.

Tragically, our sensationalist media also know that fear grabs people's attention. Our collective crisis fatigue is now so great that we ignore truly significant threats such as climate change and energy decline. Our anxiety is diverted into worrying whether it's safe for our children to step outside the 4WD (SUV). But soon we will be worrying if we can find or afford to put food in their mouths.

Sniktitt på 'State of the Future' 2009

 

The planet's future: Climate change 'will cause civilisation to collapse'

 

An effort on the scale of the Apollo mission that sent men to the Moon is needed if humanity is to have a fighting chance of surviving the ravages of climate change. The stakes are high, as, without sustainable growth, "billions of people will be condemned to poverty and much of civilisation will collapse".

This is the stark warning from the biggest single report to look at the future of the planet – obtained by The Independent on Sunday ahead of its official publication next month. Backed by a diverse range of leading organisations such as Unesco, the World Bank, the US army and the Rockefeller Foundation, the 2009 State of the Future report runs to 6,700 pages and draws on contributions from 2,700 experts around the globe. Its findings are described by Ban Ki-moon, Secretary-General of the UN, as providing "invaluable insights into the future for the United Nations, its member states, and civil society".

The impact of the global recession is a key theme, with researchers warning that global clean energy, food availability, poverty and the growth of democracy around the world are at "risk of getting worse due to the recession". The report adds: "Too many greedy and deceitful decisions led to a world recession and demonstrated the international interdependence of economics and ethics." 

6 700 sider??! Massivt.

 

Mer vannmangel

I India: India prays for rain as water wars break out

It was a little after 8pm when the water started flowing through the pipe running beneath the dirt streets of Bhopal's Sanjay Nagar slum. After days without a drop of water, the Malviya family were the first to reach the hole they had drilled in the pipe, filling what containers they had as quickly as they could. Within minutes, three of them were dead, hacked to death by angry neighbours who accused them of stealing water.

In Bhopal, and across much of northern India, a late monsoon and the driest June for 83 years are exacerbating the effects of a widespread drought and setting neighbour against neighbour in a desperate fight for survival.

India's vast farming economy is on the verge of crisis. The lack of rain has hit northern areas most, but even in Mumbai, which has experienced heavy rainfall and flooding, authorities were forced to cut the water supply by 30% last week as levels in the lakes serving the city ran perilously low.

I California: Feds document shrinking San Joaquin Valley aquifer

California's San Joaquin Valley has lost 60 million acre-feet of groundwater since 1961, according to a new federal study. That's enough water for 60 Folsom reservoirs.

This is among the findings in a massive study of groundwater in California's Central Valley by the U.S. Geological Survey. It helps shed light on the mysteries and dangers of California's groundwater consumption, which is mostly unregulated.

According to the study, groundwater pumping continues to cause the valley floor to sink, a problem known as subsidence. This threatens the stability of surface structures such as the California Aqueduct, which delivers drinking water to more than 20 million people.

The Central Valley is America's largest farming region; it's also the single-largest zone of groundwater pumping.

EDIT: Se også WATER TABLES FALLING AND RIVERS RUNNING DRY (av Lester R. Brown, utdrag fra boken Plan B 2.0: Rescuing a Planet Under Stress and a Civilization in Trouble (New York: W.W. Norton & Company, 2006))

Since the overpumping of aquifers is occurring in many countries more or less simultaneously, the depletion of aquifers and the resulting harvest cutbacks could come at roughly the same time. And the accelerating depletion of aquifers means this day may come soon, creating potentially unmanageable food scarcity.

While falling water tables are largely hidden, rivers that are drained dry before they reach the sea are highly visible. Two rivers where this phenomenon can be seen are the Colorado, the major river in the southwestern United States, and the Yellow, the largest river in northern China. Other large rivers that either run dry or are reduced to a mere trickle during the dry season are the Nile, the lifeline of Egypt; the Indus, which supplies most of Pakistan’s irrigation water; and the Ganges in India’s densely populated Gangetic basin. Many smaller rivers have disappeared entirely.

OPPDATERING: Heavy rain eases Mumbai's water woes Reddet av gonggongen.

Vannmangel i Mumbai

Mumbai faces acute water shortage

 

 

The BBC's Prachi Pinglay in Mumbai says that rainfall figures are alarming compared with last year. In many areas of the state of Maharashtra and its capital, there has been only 25% of the rainfall received by this time last year.

If more rain does not arrive soon, the lakes which supply Mumbai will recede still further.

The drought in Maharashtra in the west comes as half a million people have been stranded as rivers burst their banks due to flooding in the north-eastern state of Assam.

[...]

India's capital, Delhi, is also reeling from depleted water supplies, while many towns and villages across the country still have woefully inadequate safe drinking water facilities.

They depend largely on bore wells, which have seriously depleted the country's water table.

The BBC's Zubair Ahmed in Mumbai says farm produce is also likely to be badly affected if the full monsoon does not arrive soon.

 (lett stokket)

Flom i en del av landet, tørke i en annen... Dette må vel skrives på kontoen for klimaforandringer.