The ‘’food for man’’situation was discussed in detail in this post reemphasizes the key role that energy subsidies play in the production of food and fiber (cotton, wool, paper, wood, and so on). The age old paddy rice culture is very efficient in terms of food yield per unit of energy subsidy, but it is backbreaking for the people who plant and harvest the rice. At the other extreme, feedlot beef requires 10 cal of fuel energy for every calorie of food produced, but neither man nor beast has to do much work. Feedlots do not make very good ecological sense for another reason. Cows have a marvelous adaptation the rumen, which enables them to convert very low protein food such as grass and hay into high protein food. When cows are fed rich grains in a feedlot, this adaptation is bypassed, and the meat produced tends to be too fatty for good human health. Also, feedlots produce server watershed pollution that adds another stress on the environment, and another cost for man. There is much to be said for putting the cow back on grass.

        Avoidance of the boom and bust syndrome, as discussed on this post is another reason for considering a somewhat Les energy intensive agriculture especially for undeveloped countries. It is difficult and costly in terms of energy to sustain very high yields of the same crop over long periods of time.

          Human civilization seems to reach the most intense development in what was originally forest and grassland especially in temperate regions. Consequently, most temperate forests and grasslands have been greatly modified from their primeval condition, but the basic nature of these ecosystems has by no means been changed. Man, in fact, tends to combine features of both grasslands and forests into a habitat for himself that might be called forest edge. When man settles in grassland regions he plants tree around his homes, towns, and farms, so that small patches of forest become dispersed in what may have been treeless country. Likewise, when man settles in the forest he replaces most of it with grasslands and croplands (since little human food can be obtained from a forest), but leaves patches of the original forest on farms and around residential areas. Many of the smaller plants and animals originally found in both forest and grassland are able to adapt and thrive in close association with man and his domestic or cultivated species. The American robin, for example, once a bird of the forest, has become so well adapted to the man – made forest edge that it has not only increased in numbers but has also extended its geographical range. Most forest birds in Europe have ditches from the forest to gardens, cities, and hedgerows or else they have become extinct, since there are no longer many large tracts of unbroken forest. Most native species that persist in regions heavily settled by man become useful members of the forest – edge ecosystem of man, but a few become pests. The worst pests, however, are more likely to be species introduced from afar, as was discussed in that’s post.

        If wee consider croplands and pastures as modified grassland of early succession types, then man depends on grasslands for food, but likes to live and play in the shelter of the forest, from which he also farmers useful wood products. At the risk of oversimplifying the situation we might say that man in common with other tropospheres seeks two basic things from the landscape; ‘’production’’ and ‘’protection’’ but unlike lower organisms, he also finds aesthetic enjoyment in the beauty of natural landscapes. For mankind, forests provide all three needs, but especially the latte two. In many cases the monetary value of the wood, if harvested all at once, is far less than the value of the intact forest that provides recreation, watershed protection, home sites, and so on, plus a modest harvest of wood as well.

       All the energy in the world would be of no avail if the nutrients required by life and the materials required by commerce are not continuously fed into the ecosystem or recycled within the ecosystem, or both. The interdependence of energy follow and material cycling is shown in post and the basic principles of nutrient cycling in the biosphere were discussed in post. The point was also made that as man depletes the reservoir storage bins, recycling not only becomes necessary, but some of the energy flow has to be diverted from productive processes (that is, new growth) to power the recycle process. Post provides an overview of three alternate depletion patterns for minerals such as iron, copper, aluminum, and so on, required in huge quantities by industrialized civilization. A one – way pastern of unrestricted mining, use, and throwaway is projected to lead to a boom and bust, as shown by curve a. some key metals, such as copper, could be ‘’mined out’’ by the year 2000. Depletion time could be extended by partial recline and less wasteful use, as shown by curve b. efficient recycle, including the necessary energy allocation, combined with stringent conservation and substitutions (switching to a more abundant material whenever possible) can extend the mineral depletion curve substantially (curve c). it remains to be seen whether mankind will, or can, make a choice between these options, or whether mankind will, or can, make a choice between these options, or whether events will force some other choice. As with fossil – fuel energy the total amount of minerals in the earth’s crust (and in sea water) is very large, but as the concentrated, easily mined supplies are dispersed, procurement becomes increasingly costly both in a monetary sense and in terms of ill effects on the environment. For a comprehensive review see the national academy’s report, resources and man, edited by cloud (1969).

       The world economics means literally ‘’management of life’’ and is derived from the same root (mimic; management) as economics, the term term that literally means ‘’management of the house’’. In most dictionaries economics is listed a synonym of ecology, but the word may now be appropriate for an expanded economics of the ecosystem in which monetary values, cost accounting, and management of natural process are included along with man’s works. Such a special or might not be needed if economists where enthusiastic about extending their traditional discipline to include the works of nature. Most economists express the opinion that there is more than they can cope with in man’s ‘’house’’ and that another discipline is needed to deal with the combined ‘’house’’ of man and nature. In any event, all agree that the time has come to put greater emphasis on the value of the work of natural systems and to the impacts, both good and bad, that are external to business operations.

      Table provides and example of how monetary evaluation of a natural system might be extended to include useful work performed be self maintaining ecosystems. Lines 1 and 2 represent conventional

four bases for economic evaluation of a tidal estuary.

  

Bases for economic evaluation, while lines 3 and 4 extend the valuation to include the capacity of the tidal estuary to assimilate wastes and to provide general lif support for man’s fuel – powered systems two values are shown for each line, an annual return and an income capitalized by dividing the annual return by an interest rate (5% or 0.05 in this case) a standard procedure in resource economics (see barlowe, 1965)

       Although natural seafood harvest and recreational values accruing from very large areas are impressive, they are small on an acre basis when compared with real estate values that the estuary might have if covert from its natural state to some developed state (as, for example, if the estuary was filled in for housing or factory development) oyster culture or other intensive aquaculture would increase some what the commercial return from the estuary. However, the estuary in its natural state has a much greater value to the public as a whole in terms of its waste assimilation capacity and general life support especially as the intensity of adjacent man made development increases. The waste assimilation value, as estimated in table, is based on the cost of tertiary treatment in treatment plants built and maintained by man. In other words, this is what it would cost society to treat wastes in amounts not exceeding the reasonable capacity of the estuary to metabolize treated municipal and nontoxic industrial wastes if the estuary was not available to do this useful work. The estimate for general life support was calculated by multiplying the total productivity of the estuary times and energy dollars conversion factor. One such conversion suggested by H.T. Odom (1971) is based on the ratio of the gross energy consumption and the gross national product (GNP) for the country or region in question. As would be expected, the energy/GNP ratio varies in different countries. In and energy conservative country such as New Zealand, that does not have a lot of heavy industry, about 7000 kcal of energy is consumed annually for each dollar of GNP. For the united states the energy dollar ratio has fluctuated between 10,000 and 25,000 kcal per dollar between 1945 and 1970. Using a conservative figure of 10000 kcal =one dollar and annual production rate for the estuary of 10,000 kcal m^-2 or 41 . 10⁴ per acre, then the annual return comes to $4100 and the long term value of an acre amounts to $82,000 (see line 4 table). Since ‘’productivity’’ is a measure of a natural system’s capacity to do all kinds of useful work, such as aster treatment, CO₂ absorption, O₂ production, seafood production, wildlife habitat maintenance, protecting cities from stomps, transportation, and on, then converting work energy to money is a convenient way of making a economic evaluation of a given natural system.

       In the example just given what might be called the ‘’social aloes’’ (lines 3 and 4 table) inherent in preserving a natural estuary exceed the immediate or short term commercial values. Unless the former values are recognized and appropriate action taken to preserve them, the pricing system based on incomplete accounting will tend to force an irreversible artificial development of estuaries, floodplains, watersheds, and prime farmlands even though it is in the general public interest that such areas continue to function a slife support ecosystems. The water situation briefly mentioned on post  is another example of how an urban dweller benefits from nature’s recycling work. The cost of water produced by a natural watershed is very much less than the cost of artificially recycled water.

     Putting a monetary value on the free work of nature does not solve the problem of the conflict of interest between the value to the property owner and the value to society where the area in question has a high social or public value in its natural state, but also a high real estate value if developed to something else. But at least this approach helps bring general recognition of values that are either not recognized or in danger of being lost through public apathy . for more on this approach see gosselink, odum, and pope (1974).

As alluded to in the discussion of pollution, environmental debits as well as assets need to be included in economic assessments, especially environment damaging residuals of manufacturing which in all but a very few countries escape control by the economy. A variety of incentives, sanctions, laws and governmental controls aimed at closing his dangerous gap In economic institutions are being discussed and tried out. Evidences of citizen concern are the increasing number of lawsuits aimed at halting pollution and what individuals and groups consider unwise alterations of the environment. In turn this has stimulated a judicial interest in cases involving the environment. Environmental law has become a new research and teaching focus in many law schools. From these largely uncoordinated efforts some generally agreed upon ground rules ill hopefully emerge. There is no shortage of good ideas for economic and judicial reforms if he number of new books and articles on the subject is any indication. A sample of these are listed in the ‘’suggested readings’’ list at the end of the book.

In the united states the national environmental protection act (NEPA) represents the first attempt to provide a nation wide legal basis for extending value systems to include the natural environment. The act requires that ‘’impact statements’’ be prepared for all large proposed man made alterations. Hopefully this admitted stop gap measure will lead to a total assessment procedure that includes environmental and social cost benefits along with purely economic ones.

Perhaps the ultimate solution to the problem of joining ecological and economic values is to adopt energy units instead of monetary units for all values. The value of goods and services can certainly be measured in energy in its as well as in dollars and cents; and, as we have seen, the value of the work of nature can best be expressed in energy  units. Perhaps energy will probe to be the basic ‘’currency’’ for the proposed new science of economics.