December 15, 2006
The impact of modern agriculture on land use
Agriculture has only been around for about 10,000 years and the reasons for its success are not clear since the archeological evidence suggests that early farmers were, nutritionally speaking, not as well off as their contemporary hunter-gatherers. It may have been that since grains can be stored over years of bounty and used in lean years, farmers were better able to withstand adverse times and thus better able to sustain themselves over longer times than their rivals in lifestyles.
However, the rise of agriculture led to some serious distortions in the use of land. In nature, diversity abounds, for the simple reason that different plants species provide services for others. Some provide shade, others fix nitrogen, others protect from wind, others retain water, and so on, each enabling the others to flourish. So natural lands tend to produce a mixture of these various forms of life. The widespread growth of farming and the use of lands for single crops like rice, wheat, and corn marked a significant change since it stripped the land of its diversity.
These crops like wheat, rice, and corn have some advantages. Mainly they transform solar energy into bundles of carbohydrate energy that are tight, transportable, and relatively long lasting. Apart from the hydrocarbons like oil, these are the most concentrated form of energy. But in creating this new form of agricultural energy, we have been essentially drawing upon the reserves of energy created and stored in the land over periods of millions of years before the arrival of agriculture.
Most of this stored agricultural energy existed in the form of prairies. In his February 2004 Harper's essay The oil we eat, Richard Manning describes how energy from the Sun is stored in this particular form of plants.
A prairie converts that energy to flowers and roots and stems, which in turn pass back into the ground as dead organic matter. The layers of topsoil build up into a rich repository of energy, a bank. A farm field appropriates that energy, puts it into seeds we can eat.
The cost of using that topsoil for farming is apparent, according to Manning. "Walk from the prairie to the field, and you probably will step down about six feet, as if the land had been stolen from beneath you." This represent our using up of the world's long accumulated energy capital that has been stored in the soil. Jared Diamond in his book Collapse: How Societies Choose to Fail or Succeed (p. 489) similarly saw a visual example of this during a recent visit to Iowa where a church had been built in the 19th century in the middle of farmland. As a result of the land around it being cultivated over the years and using up the stored resources in the soil, the church now stands like an island about ten feet above its surroundings.
As we use up this soil this way, we have to replenish it using artificial fertilizers. "Oil is annual primary productivity stored as hydrocarbons, a trust fund of sorts, built up over many thousands of years. On average, it takes 5.5 gallons of fossil energy to restore a year's worth of lost fertility to an acre of eroded land—in 1997 we burned through more than 400 years' worth of ancient fossilized productivity, most of it from someplace else."
So after using up our inheritance that was in the rich soils, we use up our inheritance that was stored in the form of oil to cover up for the first loss, borrowing from Peter to pay Paul, so to speak. This process was accelerated by the arrival of what are called "wheat-beef" farming people six thousand years ago who, within the relatively short time of 300 years, became the dominant agricultural group, pretty much eliminating the hunter-gatherers. But single crop agriculture like wheat depletes the soils, leading to famines. Manning points out that between the years of 500 and 1500, "Britain suffered a major "corrective" famine about every ten years; there were seventy-five in France during the same period."
However, as these two countries became sea-faring colonial powers, they were able to use the riches of the colonies to reduce the famines at home. This also led to inequalities in resource consumption between the colonizers and the colonized.
But as the populations of these wheat-beef communities grew because of the abundance of food, they had to keep moving on, finding new sources of prairie grasslands to conquer and use up. After they arrived in the US, this drive to open up fresh lands happened here too, as settlers moved west searching for new land in order to tap its vast reserves of soil energy.
But at some point the sources of new land became exhausted. There were no new prairie frontiers to exploit. So then what happened? The 'green revolution' occurred in which genetic modifications produced rice, when and corn species that, combined with the use of increased irrigation and artificial fertilizers, produced three times the yield they had before. Most people might think that this was a good thing, since it enables the production of more food that can feed more people more cheaply. Manning argues that this is the worst thing to have happened.
One reason, Manning argues, is that it moved poor people off their own land while enabling their growth in numbers. "In the forty-year period beginning about 1960, the world's population doubled, adding virtually the entire increase of 3 billion to the world's poorest classes, the most fecund classes. The way in which the green revolution raised that grain contributed hugely to the population boom, and it is the weight of the population that leaves humanity in its present untenable position. . .[T]he methods of the green revolution . . . added orders of magnitude to the devastation. By mining the iron for tractors, drilling the new oil to fuel them and to make nitrogen fertilizers, and by taking the water that rain and rivers had meant for other lands, farming had extended its boundaries, its dominion, to lands that were not farmable."
It is clear that we cannot go on consuming resources at this rate. It seems to me like we have only three choices:
1. Perpetuate existing wide disparities in rates of consumption by the use of brute force. This will inevitably lead to more and more global conflicts, and an inevitable collapse as resources get used up.
2. Allow for increased rates of consumption globally as the newly emerging countries like China and India also start to consume at current first world rates. This will lead to an even more rapid global collapse than option 1 since resources will be used up even more quickly.
3. Reduce consumption rates in the first world while at the same time making resources more equitable worldwide so that we can bring worldwide rates to a level that is sustainable and yet provides the world's population with a decent although not luxurious standard of living.
While I favor the third option, that requires global cooperation and sharing, ideas that are not that popular these days. I fear that the other two options are more likely to be adopted.
POST SCRIPT: Middle East politics round up
The invaluable Juan Cole gives a handy round up on the state of play in the Middle East, including the emergence of Saudi Arabian interests as a big factor. He also discusses something that has not been emphasized much in the media, and that is the possible reason why Dick Cheney was "summoned" to Saudi Arabia just after Thanksgiving and was "read the riot act" by the Saudi king, and the abrupt resignation this week of the Saudi ambassador to the US.
The fact that the Saudis can snap their fingers and Cheney immediately gets on a plane and goes to get lectured by them is another indication of how weakened the US has become by its invasion of Iraq. At least we can be thankful that Cheney didn't shoot the Saudi king in the face.