Village Tree


ARTICLES FROM DECEMBER, 1999

What Is In Your Water?: One value of ecosystems!

by David Borton (Ghana, '65-67)

Fresh water sources usually contain a variety of contaminants including:

  1. Microbes such as giardia, cryptosporidium, and viruses which come from humans and other animals, both wild and domestic.

  1. Inorganic chemicals such as lead, salts, and fertilizers, even radioactive contaminants.

  1. Organic chemicals including natural vegetative decay, pesticides, industrial chemicals and petroleum products.

  1. Carcinogenic compounds created by chlorination to kill the last of the microbes in the water and in the pipe delivering the water to consumers.

The sources of these contaminants can be directly deposited from the air or washed in with the rain and snow.  There are point sources such as sewage treatment plants, industrial sites and accidental spills.   There are extended sources from urban, farming and forested land.   Traditionally water sources have been clean and pure.  The water cycle powered by the sun runs through ecosystems, which filter out the contaminants and use them to grow plants and animals. 
Until recently the water supply for New York City has been cleaned by ecosystem services.  The reservoirs in five counties west of the Hudson River and two counties east of the river have had high quality water supplying 1.4 billion gallons to some 8 million persons.  Now, however, reservoirs in the two closest counties have water that has to be diluted with cleaner water to reach drinking water standards.
New York is spending money to solve a problem that the ecosystem used to solve for free.  First, New York will have to build a filtration plant to filter the 10% of the water that comes from the east of the
Hudson.  Second, New York City will pay the five counties on the west of the Hudson to maintain the ecosystems of the watershed so that the ecosystems can continue to provide high quality water.
The costs of repairing the human damage to the ecosystem's ability to provide quality water is one way to see the value of ecosystems.  For New York City this cost starts at an estimated $600 million  for a filtration plant for 10% of the water.  Then add $1.4 billion for protecting the watershed in the seven counties which supply the water.  That's over $2 billion to partially restore what people have taken for
granted as a free ecosystem service in seven of New York State's 62 counties.


Ecosystem Services

by David Borton (Ghana, '65-'67)

Economics can tell us the price of a bottle of drinking water, but can not put a value on our water sources.  Economics can tell us the price of a tree, but can not put a value on a forest.

Standard neoclassical economics does not value the biosphere in which all economic activity takes place.  Economics calls natural resources - minerals, air, water, bio-diversity, and solar energy - "externalities" and at best marginalizes them.  Most of us, in contrast to economists, know that we are wholly dependent on natural flows.  Fortunately, there are new patterns of thought called "ecological economics," which do not accept the environment as just another substitutable input. 
One of the issues considered by ecological economics, but not by traditional economics , is "the value of the world's ecosystem services and natural Capital."  The question of value is difficult and complex with no single definite answer.  However, it is an important question that needs to be considered.  Robert Costanza and a group of ecological economists considered this question in a paper of that title in Nature, May 15, 1997, pp. 253-260.
The paper considers 17 ecosystem services such as water supply, food production, waste treatment, soil formation, water and climate regulation, etc.  It looks at the world as 16 different biomes such as forests, grass/range lands, deserts, wetlands, oceans, coastal regions, and even urban areas.  For each biome the group attaches a reasoned number for the dollar value of each ecosystem service.  They only look at values in units of billions of dollars per year.  They probably can't get the numbers right, but they provide an excellent starting point for discussion.
Their results indicate that ecosystems provide a minimum estimated average value of $33 trillion.  I have trouble understanding a million, let alone a billion or a trillion.  To give some context to the number, consider that the gross national product of the world is around $18 trillion.  In other words standard economics considers only at most about one-third of the value of what goes into our lives.
We already knew that the environment provides valuable ecological services; finally some people are starting to quantify this value.

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