You cannot reduce population OR consumption, you must stabilize and then reduce BOTH
Commentary by Dr. Michael Lardelli
The reason why people are concerned about population growth is that continued population growth cancels out any other efforts that one may make to reduce the impact of humans on the planet. You cannot reduce population OR consumption. You must stabilize and then reduce BOTH to have any chance of survival for civilization.
I just stumbled onto these lecture notes from Oregon State Uni that are very informative, especially about the green revolution and how oil and genetics combined to raise food production. You need to click on the arrows at the bottom of each page to read the lot:
http://oregonstate. edu/~muirp/ grrevhis. htm
Here is an excerpt:
"WHAT CHARACTERIZES "GREEN REVOLUTION" CROP VARIETIES?
One of the most important things that makes them higher yielding is that they are dwarf compared to conventional varieties. This may sound odd, but it works because they have been bred to allocated more of their photosynthate (the carbon that they fix via photosynthesis) to grain, and relatively less of it to their vegetative parts, such as stems and leaves. The ratio of crop yield (e.g., grain weight) to total aboveground weight of the plant is called the "harvest index." Green Revolution varieites generally have a higher harvest index than do conventional varieties.
For example, old wheat varieties allocated about 20% of their photosynthate to grain, while the green revolution varieties allocate 50-55% of their fixed carbon to grain!. (The physiological maximum is estimated to be 60%, to leave enough for roots, enough leaves for sufficient photosynthesis, etc., so there isn't much room for more improvement this way!)
While breeders have been able to alter the allocation of photosynthate, they haven't been able to change significantly the amount of photosynthate produced per unit of leaf area -- that is, they haven't been able to improve on the efficiency of photosynthesis itself.
High yielding corn in US is not as dwarfed as are high yielding rice and wheat, but is high yielding (on a per area basis) because it is bred to hold its leaves more vertically than older varieties, which minimizes self-shading and allows a greater planting density. Use of herbicides instead of cultivation to control weeds also allows row to be planted more closely. The combination of these two factors allows more plants to be packed into a given area -- increased plant density – which results in increased yield on a per area (rather than on a per plant) basis.
A second factor contributing to high yields from these "green revolution varieites" is that they are relatively insensitive to daylength. (Remember, most plants flower in response to changing daylengths?) This insensitivity means that they can be planted widely across latitudes, and also can be planted more than once per year under appropriate climatic conditions.
These varieties are also tremendously responsive to fertilizer and to water. This responsiveness results in the second factor contributing to enhanced yields, specifically use of heavy inputs of fertilizers and irrigation (which the hybrids require to achieve their yields), along with pesticides in many cases.
The green Revolution undoubtedly helped to improve nutrition throughout the world. Life expectancy in lesser deveoped countries increased by 10 years in two decades (from less than 43 years in the early 1950's to over 53 years in the early 1970's), with a major portion of the increase attributable to improved nutrition."
Dr. Michael Lardelli
Senior Lecturer in Genetics
University of Adelaide, Australia
Beyond Oil South Australia (BOSA)