Wayne Stollings wrote:
Reminds me of the old myth about the lemmings except with people.
Soil depletion is not a myth, Wayne. Erosion is only part of it, and depth is only a partial indicator of true soil health but right now there is less than 2/3 the average depth of 1910 studies. Soil organic loss to nothing is in very large areas, and reduction from healthy percentage in many more. Soil has been lost to citification, salinization from salty river water over time, sterilization by insecticides and herbicides which have killed off the necessary worms, grubs, bacteria and fungi of good soil. Many places can only grow less nutritious foods through addition of petro-chemical fertilizers. Of course heavy machinery farming also requires depleting dirty fossil fuels, along with the distribution system.
In the fact of decreasing returns from increasing petro-chemical fertilizers the runoff has become the source of estuary dead zones.
AGW along with many years of non-fallowing intensive farming have led to a lot of soil loss through desertification.
Rivers used until they are dry and the same with many aquifers like our own Ogallala gone before 2040 according to the USGS. It should be noted that irrigation of the average crop increases yields 600%.
There are thresholds with many plants on when they just will not grow, whether it is less than several inches of soil, too much salt, lack of certain nutrients, the vector is toward just pockets of good soil like oases, in areas not yet hit by AGW or what will come beyond that.
Soil loss from all causes will lead to less yields. Add in AGW effects, loss of cheap energy, and loss of good water. It does not look good after 2040. Some may behave like lemmings if the alternative is worse, like those poor souls who jumped off the WTC on 9-11 rather than burn to death. Lack of water certainly causes madness, and lack of food drives many to cannibalism.
People have fought wars really over resources, and in wars/political unrest people have been lined up in front of long trenches and mass buried after being executed for existing.