Environmental Quality: An Overview
The first (and perhaps most important) insight to gain
from environmental data looked at over any lengthy period is that trends
are mixed--there are instances of improving environmental quality,
deteriorating environmental quality, and situations where little change
is apparent. We shall consider the major environmental media in turn:
Air
We will focus primarily on pollutants for which the
EPA has established National Ambient Air Quality Standards (NAAQS).
The Clean Air Act (CAA) provides for two types of standards (this is irrational,
incidentally!--DISCUSS the general stupidity of "hierarchies"): Primary
Standards are implemented to "protect the public health, including
sensitive populations such as asthmatics, children, and the elderly." Secondary
Standards are established to "protect the public welfare, including
animals, crops, vegetation, and buildings." Here are the six criteria
pollutants--the vast majority of all air pollution--along with their associated
standards: carbon monoxide (CO--8hr 9ppm or 10mg/m3; 1hr 35ppm or 40mg/m3),
lead (Pb--1.5ug/m3 maximum quarterly average), nitrogen dioxide (NO2--.053ppm
or 100ug/m3 annual arithmetic mean), ozone (O3, good in stratosphere, bad
at ground level--created when NOx reacts with VOCs--.12ppm or 235ug/m3
maximum daily 1-hour average), particulate matter with particle size less
than 10 microns (PM-10, replacing TSP in 1987--50ug/m3 annual arithmetic
mean, 150ug/m3 twenty-four hour), and sulfur dioxide (SO2--80ug/m3 annual
arithmetic mean, 365ug/m3 twenty-four hour; secondary standard 1,300ug/m3
in 3-hours). Discuss the sources and damages for the various air
pollutants.
The EPA tracks both emissions and air quality.
Emissions of the six criteria pollutants, with the exception of NO2 which
increased 14% (DISCUSS why), have declined considerably from 1970-1994
(latest data). The decrease in lead emissions is the most dramatic,
at 98% reduction, but CO decreased 23%, VOCs decreased 24%, PM-10 decreased
78%, and SOx decreased 32%. In terms of ambient air quality
(measured at some 4,000 monitoring sites for the period 1985-1994) CO decreased
28%, lead decreased 86%, NO2 decreased 9%, ozone decreased 12%, PM-10 decreased
(between 1988-94) 20%, and SO2 decreased 25%. There was, of course,
progress prior to 1970 as well, both for stationary sources (primarily
SO2, PM-10, VOCs) and mobile sources (NO2, CO, lead, VOCs). Also,
the 189 non-criteria chemicals referred to as "hazardous air pollutants,"
that are believed to potentially lead to health problems (cancer, reproductive,
other) have declined by 33% between 1989 and 1993 alone. EPA is also
working currently on reductions in stratospheric ozone depleting air pollutants,
and acid rain generating pollutants in addition to the proceeding.
NOTE: This progress occurred despite population growth (27%), growth in
vehicle miles traveled (111%), and growth in income (90%)! There
are, however, still about 62 million Americans who live in counties that
violate one or more of the standards established for the criteria pollutants
(mostly, ozone violations).
Discuss air dispersion models and their value in
determining benefits and costs of control that vary greatly over space.
Policy options involving where (three dimensionally) and when (emergency
options versus on-going efforts) clean-up occurs, as well as overall levels,
are very relevant to non-global air pollution problems. (Grid Figure)
Water
We break our discussion up into ground water and surface
water, each of which has unique water quality issues. For example,
recreational/ecosystem issues are not important for ground water, but are
very important for surface water, while subsidence or seawater intrusion
are important issues for groundwater and not for surface water.
Ground Water
Ground water in U.S. aquifers (contiguous 48 states)
is extremely important and fortunately very abundant (250 times as much
ground water as surface water--this is equivalent to the water contained
in 200 years of Mississippi River water flow) . Forty percent of
the public water supply (97% in rural areas) comes from groundwater.
Between 30 and 40% of the water used by the multi-billion dollar agricultural
industry comes from groundwater. The vast majority of all groundwater
is unpolluted (98%?), but those areas that are polluted tend to be more
important since they are usually near people. Problems of heavy metal
leaching, nitrates, toxic chemicals, fecal colliform, are among the pollution
problems found. Pollution often moves very slowly in aquifers, as
little horizontally as 6" per year in some cases--implies one well might
be polluted but neighboring wells may not be for many years, if ever.
Other problems include land subsidence (serious in places) and salt water
incursion.
Surface Water
Surface water in the U.S. has been generally improving
for many years. The Great Lakes are in vastly better shape than they
were thirty years ago. Eutrophication problems in lakes and streams
(dredging issues, though--do you want to "stir it up?"). Navigable
rivers and streams have also generally improved. Pollutants usually
considered are: BOD (a measure of pollution loading, actually), DO (dissolved
oxygen--overall health measure), pH (acid rain issues--note "clean-looking"
can be misleading), turbidity (analogous to "coefficient of haze" for air),
ammonias, nitrites, nitrates, heavy metals, pesticide and fertilizer runoff.
In developing countries 44% of people had access
to safe drinking water in 1980, while 74% did in 1994. (Terry Anderson
in WSJ)
Water "shortage" issues (criminal or economic issue?)--shortage
of rational pricing policy, not fundamental shortage of water! (urban price
elasticity is 1.2 while rural price elasticity is 2). Only 2% of
Eastern water suppliers establish water prices that vary seasonally!
And, astoundingly, 33% offer quantity discounts to users who use more water!
Eastern water laws *prohibit* people from buying and selling water--we'll
come back to this as an application of the Coase Theorem. Proper
policy won't make droughts disappear, but they will greatly ease the pain
they impose when they occur.
Hydrology modeling and its policy implications:
where and when again matter greatly to appropriate control of water pollution.
("Reach" Figure).
Oceans and the World's Fisheries--a true tragedy at this time
Paraphrased from article in The Economist, March 19, 1994:
After growing rapidly after WWII (tripling to over
60m tons in only 20 years), fishing developed more slowly in the '70s and
'80s, peaking in 1989 at 86m tons. Most now believe we have long
ago exceeded sustainable landings of wild fish. When catches of the
most valuable fish in northern waters (e.g. turbot, halibut) started to
fall, fleets began chasing other species that had been thrown back as "trash"
only a generation before (e.g. whiting, spiny dogfish, and others).
They also fished distant waters and found massive catches of a few low-value
species. The FAO (Food and Agriculture Organisation) notes that it
was these short-lived fish (e.g. Alaska pollack, Peruvian anchovetta and
Japanese pilchard) that swelled the world catch in the 1980s. The
declining trends were masked because catches were measured in tons, not
dollars.
Almost all of the 200 fisheries monitored by the
FAO are fully exploited. 1/3 are depleted or heavily over-exploited,
almost all in the developed countries. Although fishermen still catch
relatively few of the 15,000 species of fish extant, most of the remainder
are expensive to catch, unappetising, or both.
The world's 3m or so trawlers, purse-seiners, and
gill-netters are operating at an estimated $22 billion loss (1989).
New technology (cheap nylon filament, refrigeration, spotter planes and
helicopters, directional sonar, and satellites) has failed to offset these
losses, while speeding the declines of fishing grounds. The rich
countries' fleets have outstripped their fishing grounds' capacities by
such a long way that Iceland and the European Union could cut their fleets
by 40%, Norway by 2/3, and all three would still catch as much fish as
they do today. Governments have encouraged this excess by subsidizing
fishing fleets, often as a form of regional aid and in response to falling
catches. Not only costly in terms of resource use, overfishing is
waste on a grand scale: American fishery managers estimate that the U.S.'s
catch is about half as valuable as it could be if fish stocks in federal
waters were allowed to recover. The EU has said that its waters could,
if properly regulated, yield a further $2.5 billion worth of fish a year.
The FAO estimates the annual loss worldwide at $15-30 billion.
In addition to overfishing, development and pollution
are also reducing stocks. According to Paula Brouha, director of
the American Fisheries Society, 11-15m salmon once spawned in the Columbia
river system. Now there are only 3m of which 2.75m come from hatcheries.
So much of the river system has been dammed that only 250,000 salmon can
find their way back to old spawning grounds. Moreover, 3/4 of the
American catch comprises species that depend upon estuaries (often as habitat
for juveniles, which can safely feed in the shallows). But pollution,
filling in of lagoons and wetlands to make land, upstream water withdrawal
affecting salinity, render the estuaries themselves vulnerable.
Over-fishing and pollution rarely lead to extinction
(though even this is possible for a few large, slow-growing and valuable
species, such as the bluefin tuna). And fish will remain on menus,
albeit at higher prices. Indeed, as the price climbs and biotechnology
develops, the most valuable fish will increasingly be farmed. Aquaculture
yielded more than 12m tons in 1990, and is growing by more than 10% per
year (fin-fish comprise 70%, shellfish 25%, and shrimp about 6%).
Prior to 1976 most world fish stocks were open to
all-comers, making conservation almost impossible. Then, an international
agreement extended some aspects of jurisdiction from 12 to 200 nautical
miles offshore, creating areas now known as "exclusive economic zones."
Because most commercially attractive fish live near the shore, the agreement
brought many fisheries under the control of the nearest country.
One would think that this might greatly lessen the problem of over-fishing.
The idea is that marine biologists could set quotas based on the maximum
sustainable catch and managers could try to limit fishing by licensing
boats, restricting fishing times, and regulating fishing gear (size of
boats, nets' mesh, etc.). These approaches are not efficient, although
they may be better than current outcomes, since after 18 years of "management"
the developed-country waters are in worse shape than ever. For example:
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Atlantic cod catch peaked (800,000 tons) in 1968, collapsed in the '70s;
by 1992 managers recommended a catch of less than 50,000 tons (Canada closed
their fishery completely)
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In the North Sea the spawning cod stock fell to 66,000 tons in 1990, barely
a third of the FAO's safe minimum.
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In 1975 the Alaskan fleet enjoyed a 120 day season on Pacific halibut;
now the year's entire catch is obtained in one or two 24-hour "derbys"--fishing
more would result in too few halibut to spawn future catches.
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The Alaskan herring-roe fishery is open for a mere 40 minutes a year.
The problem underlying the preceding numbers (and solutions
currently underway) will be discussed further in class.
There are two related problems, each stemming from the "fundamental"
problem ( the "missing market"--nobody is charging the scarcity value of
the fish as they become more scarce). These problems are: 1) each
existing boat, as a result of the missing market, catches too much (the
marginal costs are understated by the unpriced fish inputs), and 2) there
are too many boats--because the missing market made the fishing industry
more profitable, encouraging entry.