Arroyo

              T ARROYO
Much Studied, Often Discussed,
Climate Change Remains an Open Issue
The
changing of the Earth's
climate, which is a topic of in-creasing
concern, is a corn-plex
issue. Much more than a mete-orological
phenomenon, climate is a
force that helps define our social en-vironment,
as well as our relation-ship
to the natural world. Therefore,
the effects of climate change-whether
parts of the earth are
becoming wetter or drier, or hotter
or colderwould be broad and pro-found.
Climate change is a natural and
recurring process. Recently, how-ever,
it has attracted special attention
because of concern about the so-called
"greenhouse effect. " In brief,
a greenhouse effect results when
carbon dioxide (CO2) and other
greenhouse gases in the atmosphere
trap solar heat. The Earth's atmos-phere
then acts like the glass in a
greenhouse, and a warming of the
Earth's climate could result. Because
of a recent and rapid buildup of CO2
in the atmosphere the greenhouse
effect, which has always been part of
the Earth's system, could now have a
more significant and possibly worn-some
influence on the Earth's climate.
As a result, climate changeits
extent, its global occurrence, its
effects and, indeed, whether perma-nent
climate changes are in fact oc-cunningis
a topic of intense investi-gation.
Scientists are examining past
and present environmental condi-tions
to better understand how the
WATER RESOURCES RESEARCH CENTER UNIVERSITY OF ARIZONA
Vol. 3 No. i April 1989
climatic system works. At the same
time social scientists are studying
climate change to understand its im-plications
for public policymaking.
Scientists are now gathering and
analyzing a great and varied range of
information about climate change in
an effort to improve our understand-ing
and predictive abilities. Included
among these scientists are research-ers
at Arizona universities. They
include geoscientists, hydrologists,
geographers, ecologists, atmospheric
physicists, tree-ring researchers and
political scientists. Together they are
working to better understand the oc-currence,
extent and impact of
present and future climate changes.
Since Arizona researchers are
involved in a range of climate
change studies, the issue will be
reviewed by discussing various
research projects that address key
climate change concerns. A review
of this research will help convey the
multidisciplinary focus of climate
change studies; their global, regional
and local concerns; and their in-volvement
with broad spans of time,
past and future as well as the pres-ent.
Much more climate change
research is being done in Arizona
than is described in this newsletter.
The projects that are included were
selected to represent the range of
research being done in climate
change studies, as well as to bring
out some of the chief concerns
associated with the issue.
Broad Implications of Climate
Change
The work of Arizona researchers
will be more fully appreciated if
the broad implications of climate
change are first discussed. An issue
of far-reaching implications, climate
change, when viewed in a broad
perspective, is ultimately concerned
with complex relationships involving
climate, the Earth and its resources,
and social, political and institutional
activities. It is this complexity that
challenges climate change research-ers.
A scenario will help demonstrate
this complexity. If the Earth's
temperature rose, the snow line or
freezing elevation would occur at
higher altitudes. This in turn would
have an effect on the supply and
management of water resources in
the Southwest.
(Although many speculate about
climate change in Arizona and the
Southwest, little knowledge exists
about its effects, extent, or even its
occurrence in the region. Scientists,
even those who believe that a global
greenhouse warming trend is in
progress, dc) not claim to he able to
predict the precise amount of
warming, nor its regional distribution
and effect. As a result, the following
is a hypothetical situation.)
If the snow line or freezing
elevation were to rise in Arizona and
the amount of precipitation remained
the same, less moisture would he
stored as SflOW in the White Moun-tains
or the Mogollon Rim during the
winter months. Instead, winter
precipitation in these locations
would fall as rain or quickly melt off
causing winter floods along major
tributaries of the Salt and Verde
Rivers.
Further problems would develop
when western streamfiows during
April through June are greatly
diminished for lack of late snowmelt
from the higher elevations. Agricul-tural
areas in the Southwest that rely
on this seasonal flow would he
adversely affected. Other sources of
water for agricultural uses would be
needed for areas downstream of
reservoirs or small storage facilities.
Streamflows might he further
reduced through an increase in the
evapotranspiration rate. Plants
would use increased moisture
because of the higher temperatures,
with an additional moisture loss
resulting from increased evaporation.
As a result, even less water would he
available as runoff from watersheds.
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The change in the hydrologic
runoff pattern would have severe
consequences for water supply
systems with a finite amount of
storage, such as the Salt River
Project. With increased winter
runoff, storage facilities would fill,
and excess water would need to be
spilled. This would result in less
water available for year-round use.
Additional groundwater may need to
be pumped, and strict conservation
measures may be required.
More dams might he proposed to
create larger reservoirs for storage in
certain areas. The success of such
proposals, however, would involve
changes in present attitudes, since
the construction of large-scale water
projects is presently in disfavor.
Approved during a previous era,
such projects were later found to
have excessive economic and
environmental costs and, as a result,
became socially and politically
unacceptable. If additional water
storage capacity were needed, possi-bly
the economic and environmental
costs would be reconsidered.
If major and extensive new water
projects were to be built strong
federal backing would likely be
needed. This could result in the
reappraisal of another current devel-opment.
The federal government
has been reducing its support for
new large water development
projects and has become less
involved with issues associated with
water resources. As a result, states
are more actively engaged in manag-ing
their water resources. This trend
toward decentralized state decision
making in water affairs would most
likely be effected if the federal
government again needed to contrib-ute
extensive financial hacking for
water projects.
Other activities that could be
affected by a change in the hydro-logic
runoff pattern would include
hydroelectric power production,
recreational activities and instream
flows to support fish and wildlife.
The above scenario is one among
many that might occur with an
increase in temperatures. Many
other regional climatic possibilities
exist. The discussion, however, is
meant to emphasize that climate
change, whatever forni it may take,
is not without significant economic,
social, political and institutional
consequences.
The Greenhouse Effect
Much
of the current interest in
climate change is the result of
debate about the greenhouse effect.
This debate involves questions about
the occurrence of the phenomenon,
its extent and its present and future
effects on climate.
In brief, a greenhouse effect
results when the Earth's atmosphere
traps heat transmitted from the
Earth's surface. Sunlight first passes
through the atmosphere to strike the
Earth, with some of its energy re-radiated
hack through the atmos-phere
at a longer wavelength.
Certain atmospheric gases, including
water vapor and CO2, then absorb
some of this energy causing a
greenhouse effect. A greenhouse
effect is natural and supports life.
But concern about the green-house
effect is presently mounting
because scientists have found that
the atmospheric gases that cause the
effect are increasing. For example,
scientists have measured a current
0.4 percent annual increase of atmos-pheric
CO2 and have determined that
a 25 percent increase of CO, has
occurred during approximately the
last century.
Chlorofluorocarbons, methane,
nitrous oxide and numerous other
greenhouse gases are also increasing
in the atmosphere. With an increase
of such gases in the atmosphere
more energy is absorbed, heighten-ing
fears that the expanded green-house
effect will raise global tem-peratures.
Various human activities are
responsible for the buildup of
greenhouse gases in the atmosphere.
For example, the burning of fossil
fuels to support industrial develop-ment
is a major contributor of CO2 to
the atmosphere. Also, increased CO2
in the atmosphere is partly the result
of deforestation. As trees are de-stroyed
to create more farmlands
less CO2 is converted into oxygen.
William D. Sellers, professor of
atmospheric sciences at the Univer-sity
of Arizona, studies atmospheric
records to determine the effects of
increased CO2. He has found that
the most noticeable atmospheric
change occurring is a cooling of the
stratosphere or the upper atmos-phere.
Sellers believes that this
cooling, which has been one to two
degrees Celsius during the past 30
years, may he the the result of the
buildup of greenhouse gases.
Many anticipate the cooling of
the upper atmosphere, along with a
warming of the lower, as greenhouse
effects. Although Sellers has noticed
upper atmospheric cooling, he has
not yet found any significant evi-dence
of a warming of the lower
atmosphere. As a result, Sellers does
not believe that conclusive evidence
exists that the Earth's surface is
presently warming from a green-house
effect.
Further, Sellers has studied
Arizona temperatures that have
occurred since 1895, the earliest year
of accurate temperature records. He
has noticed that Arizona tempera-tures
have been above the long-term
average since 1976 hut are still lower
than temperatures that occurred at
the turn of the century. As a result,
he is unable to determine whether
the present warm spell is the result
of greenhouse warming or whether it
is a natural variation.
San Ildefonso pottery design of leaf clusterr
with distant rain
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Climate Change and
the Study of the Past
While some scientists study
current conditions to deter-mine
the presence of a greenhouse
effect, others focus on past situations
to better understand climatic dynam-ics
and the possible effects of green-house
warming. In fact, much
research related to climate change
focuses on the past, for the climate
that prevailed in the past provides
clues to what may occur in the
future. Further, by reviewing past
environmental conditions, scientists
are better able to distinguish human-caused
climate changes from those
that occur as part of natural fluctua-tions.
Important questions can then
he better answered, For example:
Are recent climatic events, such as
the summer heat of 1988, harbingers
of a new global climate being
brought about by the greenhouse
effect, or do they fit into a natural
and recurring weather cycle?
Information about the past also
has a direct and specific use. Com-puters
are being used extensively to
develop and operate models which
simulate the complex interactions of
numerous variables that together
create global climatic conditions.
Included in the models are such
variables as the amount of solar
energy entering the Earth's upper
atmosphere; the relative position of
the sun and Earth as it affects the
seasonal variance of solar energy
reaching the Earth; and the transfer
of heat between ocean surfaces and
the air.
The models are used to simulate
past and present climatic situations,
as well as to help predict future con-ditions
in response to selected
changes in input variables, such as
an increase in CO2. The accuracy of
a model can be determined by
comparing simulated data of a past
period with information about the
same period obtained through
research. The degree of similarity
between the simulated and re-searched
information determines the
accuracy of the model and its use in
other situations.
Basically, however, the study of
past atmospheric conditions helps
scientists to better understand the
Earth's total climatic system. Climate
is the result of the complex workings
of the lithosphere, the physical
climate system, and the biosphere as
each evolves, changes, and interacts.
Data and information about the
climatic past contributes to an
understanding of the entire process.
Judith T. Parrish, associate
professor in the UA geosciences
department, studies global patterns
of ancient Earth climates that oc-curred
up to over 200 million years
ago. This time period stretches
beyond what some researchers
believe is directly relevant to an
understanding of present and future
climatic dynamics.
Parrish believes, however, that it
is essential to study ancient climate,
especially during periods of extreme
conditions, to increase our under-standing
of the total climatic system.
An understanding of these conditions
will help researchers who now
confront the possibility that the earth
system may again experience
extreme conditions, this time, how-ever,
through human intervention.
Parrish's work includes studies of
the late Cretaceous period, which
occurred between 65 and 97 million
years ago. At this time vast coal and
oil reserves were deposited. It was
also a time of high global tempera-tures,
possibly caused by a high CO2
level in the atmosphere, a condition
that may be developing today.
To determine the temperatures at
that time, Parrish, along with a
paleobotanist, studies fossil vegeta-tion
from the north slopes of Alaska.
Alaska was selected as a site because
climate change more strongly affects
polar regions than lower latitudes.
During the late Cretaceous period
Alaska was closer to the pole than at
present.
The fossils are analyzed for
climatic information. The size and
types of trees from the period
provide evidence of moisture as do
rings from tree fossils. Broad leaf
fossils are especially helpful because
they provide a quantitative measure
or index of temperatures. With
climatic conditions known for that
high latitude and during a specific
time, global temperatures can then
he calculated.
Parrish is also studying climatic
conditions during the period when
the present continents were aggre-gated
into a single land mass or
supercontinent now called Pangea.
This was a period between 165 and
285 million years ago. Since climate
is more extreme in midcontinent
than closer to its edges, the climate
in the interior of Pangea was very
extreme and exerted a dominant
global climatic force. A study of this
extreme climatic condition enables
researchers to better understand the
climatic system under far less intense
conditions.
Various Methods to Study
Past Climates
Some
researchers examine the
more recent past by a specialized
study of various signs and signals of
past climatic activities. These
include desert varnish, tree rings,
and fossilized pollen. The various
indicators are sensitive to different
environmental conditions and
together form a composite picture of
past climatic events.
Ron Dorn, professor of geogra-phy
at Arizona State University,
studies desert varnish to understand
very long-term cycles of environ-mental
change in the desert. 1)esert
varnish is atmospheric fallout or dust
that accretes to a rock surface. A
concentration of manganese and iron
cements the varnish to the rock. The
relative amounts of manganese and
iron present in the varnish indicate
how alkaline the atmospheric fallout
4
was when a layer of desert varnish
was deposited.
A high manganese concentration
indicates low alkaline fallout which,
in turn, indicates a time of abundant
moisture. Conversely, if the manga-nese
concentration is low, the desert
dust is more alkaline indicating drier
conditions. (Dust from the Sonoran
Desert is presently very alkaline.)
Surface layers of desert varnish
represent the present, and layers are
correspondingly older as they are
taken further from the surface. Dorn
is able to establish a timeline by
collecting varnish from lava flows
that have been dated, for example,
to one million years. He then knows
the date of the oldest layer of varnish
and, assuming a uniform rate of
deposition, he can determine how
many alkaline fluctuations occurred
over a million years. This represents
an extensive record of climate
change in a desert environment.
Desert varnish provides other
important climatic information. Dorn
is presently analyzing desert varnish
to help establish an analog between
a past situation and a possible future
greenhouse condition. Desert
varnish forms on ventifacts, which
are wind-abraded rocks.
By studying the layering of
varnish on ventifacts, the wind
direction at the time the rocks were
formed can be deteiuiined. The
record of wind direction as pre-served
by the varnish on the venti-facts
enables researchers to recon-struct
wind circulation. Such informa-tion
is intended to he compared with
contemporary climatic signals to help
determine if greenhouse conditions
are presently influencing the Earth.
Dorn is studying ventifacts that
formed about 5,000 years ago during
a warm period in the mid-Holocene.
Some believe this period shares
conditions with those that may
develop in a future greenhouse
situation. Dom is conducting this
research in collaboration with the
ASU Laboratory of Climatology.
Researchers at the UA's Labora-
tory of Tree Ring Research are
studying tree rings to reconstruct the
history of climate and water supply.
The laboratory is recognized world-wide
for its work in this field, which
is called "dendroclimatology."
Trees usually grow a new layer
of wood annually just under the
bark. If a cross section of a tree is
examined, a distinctive pattern of
rings is observed, each ring consist-ing
of a separate layer of wood. The
rings are datable to their exact year,
and each records climatic informa-tion.
As a result, dendroclimatology
is able to precisely date climatic
conditions recorded by the rings.
Researchers obtain various kinds
of climatic information from the
rings. To determine the amount of
moisture during various years, the
rings are carefully measured. Wider
rings indicate years of greater
moisture. Thin rings reflect dry
years.
Further climatic information is
obtained by analyzing X-rays of tree
rings. X-rays allow researchers to
interpret wood density. Since wood
density is affected by temperature,
an analysis of a ring provides
information about the temperatures
that prevailed during the growing
season of a tree.
David M. Meko, associate staff
scientist at the UA Tree Ring Labora-tory,
along with Charles W. Stockton,
professor of dendrochronology at the
laboratory, have studied tree rings in
the western United States to deter-mine
if variations in runoff have
been consistent throughout the
region over time. Although no
long-term runoff records exist, runoff
can he inferred from tree rings.
This research indicates that the
entire region experienced a wet
period in the early 1900s which
peaked at about 1915. After that
time runoff dropped significantly,
with the duration of dry conditions
depending upon geographic vari-ables.
Drying continued longer in
southern locations, with Arizona still
feeling the effects in the late 1950s.
Dry conditions continued for shorter
periods of time in northern locations.
They generally ended in the late
1930s in Montana. This swing
between dry and wet was the most
extreme of the time period covered,
1700 to 1960.
The research provides no definite
evidence of regular cycles of wet-and-
dry periods in the West. In the
south and central areas of the West,
however, certain variations occur,
usually every 20 to 25 years. They
are not regular enough though to
establish a predictive pattern.
The study of tree growth has an
additional application to the study of
climate. Some scientists believe that
an increase of CO2 in the atmosphere
might result in additional tree
growth. Laboratory research indi-cates
that additional tree growth has,
in fact, occurred in the mountainous
regions of the West. Researchers be-lieve,
however, that it is the result of
high precipitation in the late 1970s.
Analog Found for Study of
Greenhouse Conditions
Two
Arizona researchers analyze
pollen to determine climatic his-toriesOwen
K. Davis from the UA
geosciences department and S. Scott
Anderson of the Northern Arizona
University Quaternary Studies
Program. They collaborated together
on an Environmental Protection
Agency (EPA) project to study fossil
pollen to identify a modern analog
for a past condition. The study will
help determine what future climatic
conditions might prevail in central
California, if the area is affected by
greenhouse warming.
To obtain climatic information
from pollen an index or measure
needs to be established to relate
pollen to climatic variables. This is
done by measuring the pollen rain in
modern vegetation zones under
different climatic conditions. For
example, pollen rain would he meas-ured
in the Sonoran Desert, in piñon
5
juniper woodlands, ponderosa pine
forests, and other vegetative zones.
Once extensive information is
gathered about modern pollen rain
in various vegetative zones it is
matched with climatic data from
those same areas. Through statistical
analyses pollen and climate can then
be related. An index is thus estab-lished
that can be used to interpret
pollen from fossil records.
This technique was used in the
EPA study. The study would estab-lish
how plants actually responded
during a period with temperatures
that are expected to be achieved in
the future through greenhouse
warming.
The researchers examined pollen
from meadows and lakes in central
California. They determined that
about 9,000 years ago the climatic
conditions were probably fairly
similar to what might he expected in
100 years, if the greenhouse effect is
fully operative.
The conditions identified by the
two researchers matched the results
of a computer simulation of the
environment at that time. The
researchers found that instead of
today's fir and pine forest, pine and
open vegetation would dominate.
Analogs are useful tools, hut
Davis cautions that they have
limitations. He explains that the
global warming of 9,000 years ago
occurred because of increased solar
energy concentrating on the northern
hemisphere. This increase was
balanced by a decrease of solar
energy in winter. During the next
century, however, the warming is
expected to occur year-round,
summer and winter.
The researchers also identifed
policy implications of climate change
in the central Sierra Nevada. De-creased
timber production could be
expected, resulting in lost revenue.
Also, a general rise in temperatures
would attract tourists to the higher
elevations of the Sierra Nevada at a
time when the area would be more
susceptible to ecological damage. As
a result, the number of tourists
allowed in the area might need to he
regulated. Further, reduced precipi-tation
in the western Sierra might
encourage the planning of additional
reclamation projects to store water.
Interpreting Recent Climatic
Developments
Along
with exploring the past,
scientists are also investigating
present conditions. For example,
researchers at the Laboratory of
Climatology at Arizona State Univer-sity
have studied the warming of the
Phoenix area from rapid urbaniza-tion.
They describe the Phoenix of
the 1950s as an extensive agricultural
community with about 2.7 million
acres of farmland within Maricopa
county. Agricultural activities in-creased
the humidity of the valley
which, in turn, cooled the area.
As Phoenix became more urban-ized
moist farmlands were replaced
with hard surfaces such as pave-ments
and buildings. These surfaces
absorb heat and release it more
slowly than the natural surfaces of
desert lands. As a result, tempera-tures
increase. At the same time,
urban activities cause pollutants to
enter the atmosphere. Polluted air
absorbs radiation and reflects heat
back to the Earth's surface. This
becomes another source of warming.
Further, the warm air that rises over
the city is very stable. As a result,
the city receives less cooling winds
and less cloud cover.
Night temperatures are more
reliable as indicators of urban heat
island effects. The average summer
minimum nighttime temperature
during 1948-49 was 72.6 F and
during 1980-84 was 80.3 F, a signifi-cant
increase.
Through such techniques as the
analysis of historical records and the
interpretation of satellite images,
researchers at the laboratory have
been able to identify the shape and
strength of heat islands within
Phoenix. Most urban areas, espe-cially
those located in the Sunbelt,
create similar conditions that in-crease
warming in their areas. Some
researchers believe that what is inter-preted
as a global warming is mostly
the result of the more focused effects
of urban heat islands.
Soroosh Sorooshian from the UA
Department of Hydrology and Water
Resources is also involved with a
project that is concerned with
current climatic conditions.
Sorooshian was recently selected
by the National Aeronautics and
Space Administration to participate in
the Earth Observing System (Eos).
Eos, which is expected to be pro-posed
for development beginning in
fiscal year 1991, is a long-term
science mission to study the entire
Earth system on the global scale.
Sorooshian's contribution, however,
will he to study climate change at
the smaller, hydrologic scale.
Sorooshian is the principal
investigator of a research team that
also includes David Woolhiser and
David Goodrich. Both co-investiga-tors
are from the Agricultural Re-search
Service of the US Department
of Agriculture. Woolhiser is also a
UA adjunct professor in the Depart-ment
of Hydrology and Water
Resources, and Goodrich is a
doctoral candidate in the same
department.
Sorooshian will obtain remote
sensing data from spacecraft
launched as part of the Eos program.
The data will include hydrologic in-formation
on such characteristics as
San Ildefonso pottery design of corn with
rain
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soil moisture, vegetation cover,
atmospheric vapor, evapotranspira-tion,
precipitation and snow cover.
Sorooshian will then investigate
whether climate modeling capabili-ties
presently exist to process this
hydrologic information.
This project is significant since
most of the current climate models
focus Ofl global-scale conditions, and
hydrology traditionally is concerned
with a smaller spatial scale, such as a
watershed or river basin. Instead of
a grid about the size of Arizona,
which is what a global climate model
provides, hydrologists seek more
specific regional, and even local,
information. Sorooshian's main
concern is to develop hydrologic or
distributive models that will effec-tively
utilize the remotely sensed
data.
Such a distributive model would
enable researchers to study the
relationship between climate change
and hydrology. For example,
various possibilities may result from
a greenhouse effect, including
increased precipitation in the South-west.
A distributive model would
consider spatial and temporal
variables and be able to analyze
what effect increased rain might
have on runoff in the state.
Public Policy and Climate Change
As mentioned in a previous
section global climate change is
an issue in the process of being
defined. Research has been de-scribed
that is helping define the
issue by addressing various scientific
concerns. A discussion of climate
change, however, would not be
complete without also reviewing its
implications for public policy. The
policy actions that are taken or not
taken further define the climate
change issue.
Basic to the public policymaking
process arc facts to support informed
decisions. Enough is known about
atmospheric conditionsi.e., green-house
gases are rapidly building
upto raise the spectre of an
impending crisis and alert policy-makers
to the need to act. Not
enough is known, however, about
the effects of increased atmospheric
greenhouse gases to guide poli-cymakers
toward effective actions.
Policymakers therefore confront
the dilemma of acting on incomplete
or even conflicting information or
waiting for more solid scientific
support. Both choices involve risks.
To act on uncertain information
could lead to ineffectual and possi-bly
dangerous policies. To wait
could involve confronting a wors-ened
situation that, if addressed
sooner, could have been handled
more effectively and with fewer
adverse consequences.
For many involved in the
decision-making process, however,
the situation may not yet be viewed
as a dilemma. Confronted with
various immediate and critical issues,
many government agencies and
utility companies are neither
concerned about acting too soon on
the climate change issue nor
anxiously awaiting further scientific
information, For many, global
change has not yet achieved the
status of a looming crisis. As a result,
policymaking on climate change
concerns is often delayed.
Helen Ingram, acting director of
The Udall Center for Studies in
Public Policy at the UA, has identi-fied
various possible future public
policy scenarios for climate change
including Boom and Bust, and
Sustained Public Policy Interest
(Ingram, et al, 1989). The boom
could go bust if threatened serious
consequences begin to seem ex-treme
or exaggerated. Global climate
change might then take its place as
another popular cause that, misinter-pretecl
by science and buoyed up by
the media, was taken too seriously.
Interest in climate change might also
flag if proposed policy options are
politically unpopular.
Sustained Public Policy Interest,
however, is also a possibility. Should
this develop, should a concern about
serious consequences prevail, then
careful and credible policy analysis is
needed to provide various options
for confronting climate change
concerns.
Creative efforts at policy analysis
will be especially needed since the
magnitude and complexity of climate
change issues are often beyond
traditional policy solutions. The
regulatory approach that character-ized
much past environmental policy
may not be sufficient to curb the ill
effects of threatened global climate
change.
Appropriate policy options would
most likely need to be both preven-tive
and adaptive. Preventive
policies would involve taking actions
that would reduce the amount of
greenhouse gases being released into
the atmosphere. Such policies might
address various concerns including
deforestation, and the production
and use of greenhouse gases; but a
main objective of a mitigative policy
would he limiting the use of CO2-
producing fossil fuels. This could he
done through conservation or
promoting the use of cleaner, less
polluting fuels or sources of energy.
If examined in a global context,
however, this seemingly sound and
sensible policy could be seen as
unfair and inequitable. To be effec-tive
against global threats, preventive
policies must he gk)bally applied. If
the emission of CO2 were to be dras-tically
limited, developing countries
would suffer most since their eco-nomic
development very much
depends upon the use of relatively
cheap fo.ssil fuels. With reduced
economic development, such
countries would have increased
difficulties in providing for the well-being
of their citizens.
Adaptive policies, on the other
hand, would encourage society to
adjust to climate change. Usually
based on the belief that climate
change will be incremental and
gradual, an adaptive policy presup-poses
a flexibility in the laws and
7
institutions of society. Adaptive
policies require that incremental
changes not unduly strain society's
ability to adjust.
Water policy is seen as an area
that could he amenable to an
adaptive policy approach. If climate
change means less available water,
policies could encourage social and
institutional adaptation. At a basic
and obvious level, conservation and
efficent techniques for water use
could he stressed.
At a more complex and involved
level new management practices
could he developed to assure
flexibility of water systems. Arrange-ments
that establish the legal owner-ship
and use of water could he
reviewed. For example, the regional
and even the intrastate transfer of
water, although often presently
discouraged because of legal and
economic impediments, could he
considered as an essential adaptive
strategy to confront water shortages.
As more scientific knowledge
about climate change and its effects
accumulates, policymakers will be
better able to devise appropriate
strategies to confront the issue.
Conclusion
Climate
change, whether at the
local, regional or global level,
has always occurred and is, in fact,
an ongoing process. Some now per-ceive
it as a possible threat, how-ever,
because they fear drastic, life-disrupting
changes to world climate
from a developing greenhouse effect
caused by human activities.
Others are more optimistic. They
believe that the atmospheric buildup
of CO2 now occurring will not neces-sarily
result in a destructive warming
of the Earth. Whereas some see
present evidence of the greenhouse
effect in recent events like the
summer heat of 1988, others view
such events as part of natural
climatic fluctuations.
Meanwhile scientists continue
their research. Investigating the past,
interpreting the present, and project-ing
the future, researchers work to
understand the complex relationship
between climate, the Earth and its
natural resourcesland, water, and a
diversity of plants and animalsand
humans and their activities.
Policymakers interpret scientific
information and guide further
research efforts to help clarify policy
options.
Beyond these activities and roles
is possibly the greatest significance
of the climate change issuethe
heightened awareness of the interre-lationship
of humans and their envi-ronment.
V
Reference
Ingram, Helen M. , Hanna J. Cortner and
Marc K. Landy, "Policies of Climate
Change and Water Resources, " in
Climate Variability, Climate Change and
the Planning and ManaRement of Water
Resources, Paul Waggoner, ed. John
Wiley, NY, forthcoming 1989.
ARROYO
UNIVERSITY OF ARIZONA
Water Resources Research Center
Tucson, Arizona 85721
Lb WRR(
Water Resources Research Center
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esources
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text, the editor thanks the following for
contributing information to this newslet-ter:
Robert Balling, Sandra Brazel and
Randy Cerveny, Arizona State University,
John Keane, Salt River Project; Vick
Baker and Malcolm Hughes, The
Wa
Colleg
University of
Tucson, AZ 85721
(602) 621-7607
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Arro3.'o
Arizona Water Resources Center
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