Modern agriculture feeds the world. Below is a snippet of an article that deals with the role played by the fossil fuels in modern agriculture. (The emphasis is mine.)
AGRICULTURE
The very important role of oil and natural gas in agriculture, beyond the obvious fuelling of agricultural machinery, is often unknown. But these raw materials are the base for fertilizers by which to increase crop yields and for pesticides to protect crops from insects and diseases and to control weeds that compete with food plants. The most widely used fertilizers are compounds of ammonia, made from natural gas. Bartlett (1978) says: "Modern agriculture is the use of land to convert petroleum into food". Emphasizing the importance of petrochemicals in US agriculture, Pimentel (1998a), states
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If the fertilizers, partial irrigation [in part provided by oil energy], and pesticides were withdrawn, corn yields, for example, would drop from 130 bushels per acre to about 30 bushels.
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However, this is assuming legumes can also be used to provide a little nitrogen. Without the use of legumes, yields would decline to about 16 bushels per acre. This is about the corn yield in developing countries.
The references are at http://www.intuser.net/ufes4.php where you will find:
Bartlett, A. A. (1978). Forgotten fundamentals of the energy crisis: Am. Journal of Physics, 46(9), 876-888.
Pimentel, D. (1998a). Letter dated March 24.
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As I see it, Siegfried, advances in science, technology, medicine, and more were the direct result of two things: modern agriculture freed up people who formerly had worked the land and - even more important - the use of fossil fuels gave these freed-up people "energy slaves" that enabled them to be very creative and productive indeed.
Below (with my emphases added) are snippets from an article that explains a bit more about "energy slaves." A search for that phrase would find many more articles.
Regards,
Bill
http://www.theglobalist.com/DBWeb/StoryId.aspx?StoryId=2018
Globalist Bookshelf > Global Energy
The History of Energy Since 10,000 B.C. |
|
By John R. McNeill | Friday, April 20, 2001 |
<big snip>
From ancient times forward, notably in Persia, China and Europe, windmills and watermills added slightly to the energy supply of agrarian societies.
Incremental improvements followed for many centuries. But in the 18th century, steam engines tapped hundreds of millions of years' worth of photosynthesis, burning coal to convert chemical into mechanical energy.
Coal of course had found uses for centuries, mainly as a fuel for heating. But the steam engine's capacity to convert that heat into mechanical energy capable of doing work opened up new possibilities.
The use of steam engines
The first steam engines were notoriously inefficient, losing more than 99% of their energy. But by 1800, gradual improvements allowed efficiency of about 5% and a capacity of 20 kilowatts of power in a single engine, the equivalent of 200 men.
By 1900, engineers had learned how to handle high-pressure steam, and engines became 30 times as powerful as those of 1800. On top of this, steam engines unlike watermills and windmills could be put anywhere, even on ships and railroad locomotives.
Worldwide energy harvest
This created another positive feedback loop, in that it allowed transport of coal on a massive scale, providing the fuel for yet more steam engines.
19th century industrialization rested on this fact. World coal production, about 10 million tons in 1800, shot up 100-fold by 1900.
The worldwide energy harvest increased about fivefold in the 19th century under the impact of steam and coal. In the 20th century, it rose by another 16-fold with oil, and (after 1950) natural gas and, less importantly, nuclear power.
20th-century growth
No other century no millennium in human history can compare with the 20th for its growth in energy use. We have probably deployed more energy since 1900 than in all of human history before 1900.
Very rough calculations suggest that the world in the 20th century used 10 times as much energy as in the thousand years before 1900 A.D. In the 100 centuries between the dawn of agriculture and 1900, people used only about two-thirds as much energy as in the 20th century.
The explosion of world energy use
Even on a per-capita basis energy use grew spectacularly, four- or fivefold in the 20th century.
In the 1990s, the average global citizen (an abstraction of limited utility) deployed about 20 "energy slaves," meaning 20 human equivalents working 24 hours a day, 365 days a year.
The economic growth of the last two centuries, and the population growth too, would have been quite impossible within the confines of solely muscular energy.
<snip>
Peter <> wrote:
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