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The Concrete Gorge? February 7, 2006

Posted by thebeam in The Byways.

Our relationship with the minerals from the Earth may define both the start, and the end, of our dominion over the Earth. Maybe it is fitting that the Olduvai Gorge can be found at both limits. Such is destiny.

Back in 1959, Mary and Louis Leakey were excavating anthropological sites in a region of Tanzania called “The Olduvai Gorge”. By digging through the volcanic ash strata, they uncovered some of the oldest traces of man’s existence on Earth. Along with fossil remains for various hominids (representatives of the species Proconsul , Australopithecus/Paranthropus and Homo) they also came across some worked stone and the associated chips that demonstrated that these ‘men’ had made the great leap that placed them firmly in modern history.

What the Leakeys had discovered were the tools for shaping our environment.

Scientists have long argued that one of the milestones that marked the ascent of Man from his ancestors was the use of tools. Our puny bodies were no match in any number of physical traits that the animals around us possessed. And ‘thinking great thoughts’ didn’t put food on the table, nor hold back the cold. But by using tools, we were able to gain the critical advantage that allowed us to rise to the top of the heap.

Via digg, I came across Stuart Staniford’s observations over at The Oil Drum. Stuart had found some statistics produced by the USGS, one of which was a table of concrete production for the years 2004 and 2005.

China has recently so far outpaced the rest of the world in concrete production, that it accounted for between 45% and 47% of the concrete produced in the world for the last two years. The USA followed India on the list, but there was an order of magnitude in the disparity between the production in either India or the USA, and the production in China. China produced 1.0 Gigatons of concrete, versus 0.13 Gigatons by India and 0.1 Gigatons in the USA.

Obviously, concrete usage ties almost directly into new construction. Maybe not so obviously, it is both an indicator and a measure of energy consumption.

From Cement.org.au

The main raw material for the manufacture of clinker is a lime-bearing material. Ideally, this material will be mined or dredged from a location near the plant to minimise transport and handling costs. Limestone is the most common material used although chalk, seashell deposits, and other calcareous material (calcium carbonate) can be used. The importance of limestone ore bodies close to the plant is that it makes up around 80 per cent of the approximately 1.65 tonnes of raw material input needed to make one tonne of clinker. Approximately 50 per cent by weight of the lime-bearing material is lost as carbon dioxide in the manufacturing process.

There are four stages to this process — evaporation and preheating, calcining, clinkering, and cooling. Evaporation and preheating remove moisture and raise the temperature of the raw mix preparatory to calcining. Calcining takes place at 800-900˚C and breaks the calcium carbonate down into calcium oxide and carbon dioxide which is evolved in the process. Clinkering completes the calcination stage and fuses the calcined raw mix into hard nodules resembling small grey pebbles. Kiln temperatures in the burning zone range from 1350-1450˚C, and retention times in this zone are four to six seconds.

Obviously, this process is energy intensive. But it is also responsible for producing large amounts of CO2 gas , approximately 50% of the lime bearing material’s weight is lost as carbon dioxide gas.

Indications are that the huge demand for concrete will not continue unabated in China either. Some of the comments I’ve seen credited the use of concrete in China with the construction of the Three Gorges Dam, but the numbers don’t bear that out. Cement weighs about 1.9 tons/cubic yard, a Gigaton of Cement is sufficient to produce about 525 million cubic yards of cement. The construction budget/estimates for Three Gorges Dam project give a total requirement of 27 million cubic yards of cement, of which 2/3rds had been used by the year 2003 (see http://www.21stcenturysciencetech.com/articles/Three_Gorges.html and http://www.china-embassy.org/eng/zt/sxgc/t36512.htm for figures regarding concrete estimates of the project)

So now the question becomes, why might we find The Olduvai Gorge at the end of our dominion?

Back in 1949, a geophysicist named Dr. M. King Hubbert made the public prediction that the worlds oil supply would only support a very short era of fossil fuel consumption. He stipulated that oil was a finite resource, and that like other finite resources it would follow three simple rules.

  • Production starts at zero;
  • Production then rises to a peak which can never be surpassed;
  • Once the peak has been passed, production declines until the resource is depleted.

The midpoint of the depletion coincides with the peak of production, hence the terms “Hubbert Peak” or “Peak Oil” came to be associated with the midpoint of depletion. At the time of his prediction, he didn’t know when that point would be reached, but he didn’t think it would be too far off in the future. By 1975, he estimated that the peak would be reached in 1995. (Dr. M. King Hubbert)

Then, in the 1990’s another researcher, Dr. Richard Duncan, developed models that indicated that the “Hubbert Peak” was either at hand, or very near. He also extrapolated the future consequences of oil depletion, and in 2000 presented a paper titled “The Peak of World Oil Production and the Road to the Olduvai Gorge” at a national symposium of the Geology Society of America.

These are his conclusions:

The theory of civilization is traced from Greek philosophy in about 500 BCE to a host of respected scientists in the 20th century. For example: The ‘reference runs’ of two world simulation models in the 1970s put the life expectancy of civilization between about 100 and 200 years. The Olduvai theory is specifically defined as the ratio of world energy production and world population. It states that the life expectancy of Industrial Civilization is less than or equal to 100 years: from 1930 to 2030. The theory is tested against historic data from 1920 to 1999.

Although all primary sources of energy are important, the Olduvai theory postulates that electricity is the quintessence of Industrial Civilization. World energy production per capita increased strongly from 1945 to its all-time peak in 1979. Then from 1979 to 1999 – for the first time in history – it decreased from 1979 to 1999 at a rate of 0.33%/year (the Olduvai ‘slope’, Figure 4). Next from 2000 to 2011, according to the Olduvai schema, world energy production per capita will decrease by about 0.70%/year (the ‘slide’). Then around year 2012 there will be a rash of permanent electrical blackouts – worldwide. These blackouts, along with other factors, will cause energy production per capita by 2030 to fall to 3.32 b/year, the same value it had in 1930. The rate of decline from 2012 to 2030 is 5.44%/year (the Olduvai ‘cliff’). Thus, by definition, the duration of Industrial Civilization is less than or equal to 100 years.

The Olduvai ‘slide’ from 2001 to 2011 (Figure 4) may resemble the “Great Depression” of 1929 to 1939: unemployment, breadlines, and homelessness. As for the Olduvai ‘cliff’ from 2012 to 2030 – I know of no precedent in human history.

Governments have lost respect. World organizations are ineffective. Neo-tribalism is rampant. The population is over six billion and counting. Global warming and emerging viruses are headlines. The reliability of electric power networks is falling. And the instant the power goes out, you are back in the Dark Age.

In 1979 I concluded, “If God made the earth for human habitation, then He made it for the Stone Age mode of habitation.” The Olduvai theory is thinkable.

Taken together as a whole, oil consumption tied to increases in industrialization and modern building, are we seeing a disturbing signpost to our destiny?

With China suddenly blossoming as a major agent in the consumption of world resources, are we dooming ourselves to a concrete lined gorge in the near future?

Life and Hearts is in session. Are you ready to “Hunt the bitch?”



1. asha - July 11, 2006

what amount of concrete is consumed throught the world in a year?

2. thebeam - July 11, 2006

According to the USGS, in 2005, 2.2 Gigatons of cement were produced worldwide, up about 10% from the prior year. Cement makes up about 10-15% of the bulk of Concrete (gravel, sand and ‘other’ the rest) , so figure that maybe 20 Gigatons of concrete were produced. Presumably, almost all of it was used.

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