This link has been bookmarked by 29 people . It was first bookmarked on 08 Aug 2006, by Randen.
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04 Dec 13
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02 Jan 13
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16 Sep 12
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21 May 12
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10 May 12
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what natural gas shortages would do to fertilizer production costs
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Because the US and Canada feed much of the world, the answers have global implications
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world oil and gas reserves are as much as 80% less than predicted
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little real thinking has been devoted to the host of crises certain to follow
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solutions for these questions, perhaps the most important ones facing mankind, will by necessity be found by private individuals and communities, independently of outside or governmental help
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At present, nearly 40% of all land-based photosynthetic capability has been appropriated by human beings.2 In the United States we divert more than half of the energy captured by photosynthesis.3 We have taken over all the prime real estate on this planet. The rest of nature is forced to make due with what is left. Plainly, this is one of the major factors in species extinctions and in ecosystem stress.
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Between 1950 and 1984, as the Green Revolution transformed agriculture around the globe, world grain production increased by 250%.4 That is a tremendous increase in the amount of food energy available for human consumption. This additional energy did not come from an increase in incipient sunlight, nor did it result from introducing agriculture to new vistas of land. The energy for the Green Revolution was provided by fossil fuels in the form of fertilizers (natural gas), pesticides (oil), and hydrocarbon fueled irrigation.
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In the United States, 400 gallons of oil equivalents are expended annually to feed each American (as of data provided in 1994).7 Agricultural energy consumption is broken down as follows:
<!--[if !supportLists]--> · <!--[endif]--> 31% for the manufacture of inorganic fertilizer
<!--[if !supportLists]--> · <!--[endif]--> 19% for the operation of field machinery
<!--[if !supportLists]--> · <!--[endif]--> 16% for transportation
<!--[if !supportLists]--> · <!--[endif]--> 13% for irrigation
<!--[if !supportLists]--> · <!--[endif]--> 08% for raising livestock (not including livestock feed)
<!--[if !supportLists]--> · <!--[endif]--> 05% for crop drying
<!--[if !supportLists]--> · <!--[endif]--> 05% for pesticide production
<!--[if !supportLists]--> · <!--[endif]--> 08% miscellaneous8
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05 Apr 12
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Human beings (like all other animals) draw their energy from the food they eat. Until the last century, all of the food energy available on this planet was derived from the sun through photosynthesis. Either you ate plants or you ate animals that fed on plants, but the energy in your food was ultimately derived from the sun.
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It would have been absurd to think that we would one day run out of sunshine. No, sunshine was an abundant, renewable resource, and the process of photosynthesis fed all life on this planet. It also set a limit on the amount of food that could be generated at any one time, and therefore placed a limit upon population growth.
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Solar energy has a limited rate of flow into this planet. To increase your food production, you had to increase the acreage under cultivation, and displace your competitors.
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There was no other way to increase the amount of energy available for food production. Human population grew by displacing everything else and appropriating more and more of the available solar energy.
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The need to expand agricultural production was one of the motive causes behind most of the wars in recorded history, along with expansion of the energy base (and agricultural production is truly an essential portion of the energy base).
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And when Europeans could no longer expand cultivation, they began the task of conquering the world. Explorers were followed by conquistadors and traders and settlers.
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The declared reasons for expansion may have been trade, avarice, empire or simply curiosity, but at its base, it was all about the expansion of agricultural productivity.
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Wherever explorers and conquistadors traveled, they may have carried off loot, but they left plantations. And settlers toiled to clear land and establish their own homestead. This conquest and expansion went on until there was no place left for further expansion.
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Certainly, to this day, landowners and farmers fight to claim still more land for agricultural productivity, but they are fighting over crumbs. Today, virtually all of the productive land on this planet is being exploited by agriculture. What remains unused is too steep, too wet, too dry or lacking in soil nutrients.1
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Just when agricultural output could expand no more by increasing acreage, new innovations made possible a more thorough exploitation of the acreage already available.
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The Green Revolution increased the energy flow to agriculture by an average of 50 times the energy input of traditional agriculture.5 In the most extreme cases, energy consumption by agriculture has increased 100 fold or
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more.
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In the United States, 400 gallons of oil equivalents are expended annually to feed each American (as of data provided in 1994).7 Agricultural energy consumption is broken down as follows:
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· <!--[endif]--> 31% for the manufacture of inorganic fertilizer
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· <!--[endif]--> 19% for the operation of field machinery
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· <!--[endif]--> 16% for transportation
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· <!--[endif]--> 13% for irrigation
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· <!--[endif]--> 08% for raising livestock (not including livestock feed)
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Energy costs for packaging, refrigeration, transportation to retail outlets, and household cooking are not considered in these figures.
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Total fossil fuel use in the United States has increased 20-fold in the last 4 decades. In the US, we consume 20 to 30 times more fossil fuel energy per capita than people in developing nations. Agriculture directly accounts for 17% of all the energy used in this country.12
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As of 1990, we were using approximately 1,000 liters (6.41 barrels) of oil to produce food of one hectare of land.13
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In 1994, David Pimentel and Mario Giampietro estimated the output/input ratio of agriculture to be around 1.4.14 For 0.7 Kilogram-Calories (kcal) of fossil energy consumed, U.S. agriculture produced 1 kcal of food. The input figure for this ratio was based on FAO (Food and Agriculture Organization of the UN) statistics, which consider only fertilizers (without including fertilizer feedstock), irrigation, pesticides (without including pesticide feedstock), and machinery and fuel for field operations.
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Other agricultural energy inputs not considered were energy and machinery for drying crops, transportation for inputs and outputs to and from the farm, electricity, and construction and maintenance of farm buildings and infrastructures. Adding in estimates for these energy costs brought the
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input/output energy ratio down to 1.15 Yet this does not include the energy expense of packaging, delivery to retail outlets, refrigeration or household cooking.
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26 Jan 11
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However, on a human timescale, fossil fuels are nonrenewable. They represent a planetary energy deposit which we can draw from at any rate we wish, but which will eventually be exhausted without renewal. The Green Revolution tapped into this energy deposit and used it to increase agricultural production.
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23 Aug 10
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30 Sep 09
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29 Jun 09
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24 May 09
In their refined study, Giampietro and Pimentel found that 10 kcal of exosomatic energy are required to produce 1 kcal of food delivered to the consumer in the U.S. food system. This includes packaging and all delivery expenses, but excludes household cooking).20 The U.S. food system consumes ten times more energy than it produces in food energy. This disparity is made possible by nonrenewable fossil fuel stocks.
"At present, nearly 40% of all land-based photosynthetic capability has been appropriated by human beings.2 In the United States we divert more than half of the energy captured by photosynthesis.3 We have taken over all the prime real estate on this planet. The rest of nature is forced to make due with what is left. Plainly, this is one of the major factors in species extinctions and in ecosystem stress."
Between 1950 and 1984, as the Green Revolution transformed agriculture around the globe, world grain production increased by 250%.4 That is a tremendous increase in the amount of food energy available for human consumption. This additional energy did not come from an increase in incipient sunlight, nor did it result from introducing agriculture to new vistas of land. The energy for the Green Revolution was provided by fossil fuels in the form of fertilizers (natural gas), pesticides (oil), and hydrocarbon fueled irrigation.
The Green Revolution increased the energy flow to agriculture by an average of 50 times the energy input of traditional agriculture.5 In the most extreme cases, energy consumption by agriculture has increased 100 fold or more.6
In the United States, 400 gallons of oil equivalents are expended annually to feed each American (as of data provided in 1994).7 Agricultural energy consumption is broken down as follows: -
13 May 09
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14 Aug 07
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21 Mar 07
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22 Feb 07
greg bloomi think i have tagged and read this already.
food future green oil agriculture ecology environment energy peakoil apocalypse *toread
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12 Nov 06
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24 Aug 06
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22 Aug 06
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05 May 06
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24 Jul 04
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Assuming a figure of 2,500 kcal per capita for the daily diet in the United States, the 10/1 ratio translates into a cost of 35,000 kcal of exosomatic energy per capita each day. However, considering that the average return on one hour of endosomatic labor in the U.S. is about 100,000 kcal of exosomatic energy, the flow of exosomatic energy required to supply the daily diet is achieved in only 20 minutes of labor in our current system. Unfortunately, if you remove fossil fuels from the equation, the daily diet will require 111 hours of endosomatic labor per capita; that is, the current U.S. daily diet would require nearly three weeks of labor per capita to produce. Quite plainly, as fossil fuel production begins to decline within the next decade, there will be less energy available for the production of food.
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01 Apr 04
Earl MardleThis is relentless and, although it focuses almost exclusively on the US, it gives a clear view of the convergence of many cycles of depletion and unsustainability.
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