U.S. Global Change
FY 2000 Implementation Plan and Budget Overview
Vision and Perspective for the Decade Ahead
Stage for Global Change Research in the 21st Century
The U.S. Global Change
Research Program stands at the threshold of a major transition. Over the
next several years, in addition to continuing to improve our understanding
of the Earth’s environment and how it is changing, the program will advance
greatly our understanding of the implications of such change for society.
The research successes of the last decade have laid the foundation for
establishment of a global environmental change information service that
will allow global change research results to be applied more effectively
to national needs.
In the early 1980s, when climate research began in earnest on a global
scale, the problem of understanding the entire Earth system seemed in many
ways intractable. Climate system behavior, excepting a few well-known features
such as the ice ages and the annual march of the seasons, seemed chaotic.
Accurate prediction of the future course of change thus appeared very unlikely.
Although it was apparent that scientific research was required to increase
understanding of a set of newly identified global-scale environmental changes,
it was by no means clear where progress was most likely to be achieved.
In response to this challenge, the establishment of the U.S. Global Change
Research Program led to a comprehensive program of support for research
across a broad range of Earth system science issues. The result has been
a remarkable change in perspective. Scientists discovered the ozone hole,
in part through routine surveillance; determined its spatial extent, temporal
behavior, and chemical origins; and showed it was caused by human activities.
Observations demonstrated a long-term, statistically significant decline
in ozone amounts over most of the Earth’s lower atmosphere, much of which
is attributable to changes in atmospheric chemistry associated with human
activities. A rapid increase in scientific understanding supported a global
consensus on steps to ameliorate the problem. Ongoing research and monitoring
have shown that the emissions controls on chlorofluorocarbons (CFCs) and
related molecules implemented under the Montreal Protocol on Substances
That Deplete the Ozone Layer have begun to have an effect, as the concentration
of chlorine-containing source gases at the Earth’s surface has begun to
decrease. Field experiments, long-term global observations, and computational
modeling all played key roles in advancing our scientific understanding
of ozone depletion.
As these events took place, another group of scientists began to pursue
studies of El Niño, leading to equally remarkable scientific developments.
These studies have shown beyond any doubt that the El Niño-Southern
Oscillation process, in which the actions of the ocean and the atmosphere
are closely coupled, has some degree of predictability in its behavior.
The scientific community, working in the context of the USGCRP, successfully
predicted the onset of the 1997-1998 El Niño and some of the resulting
climate anomalies around the world. Societies made limited but significant
advance preparations; in some cases economic consequences were minimized
and loss of lives and property was reduced.
Coincident with these and other research successes, a large fraction of
the research community was achieving an even more visible and significant
result. USGCRP-supported observations and analyses played a prominent role
in demonstrating that emissions of carbon dioxide and other trace gases
resulting from human activities are changing the composition of the atmosphere.
Projections indicate that the changes over the next century will increase
atmospheric concentrations of greenhouse gases to levels not seen in tens
of millions of years — periods when the climate was substantially different
than today. Observations suggest that the human-induced changes in atmospheric
composition are already starting to change the climate. Careful measurements
of surface temperatures around the world indicate that the global average
temperature has risen substantially in the latter half of this century,
compared both to observed temperatures since the 19th century and to estimated
temperatures reconstructed from tree rings and other evidence back as far
as a thousand years. Substantial improvements in climate models have been
achieved and these models project increases over the next century in global
average temperatures of from 2o to 7o F, as well as shifts in precipitation
and a significant acceleration in the rate of sea-level rise.
Observations and monitoring from space of changing land cover, along with
the production and distribution of global land cover data, are providing
an important foundation for efforts to make land use more sustainable.
For example, satellite observations supported by the USGCRP in coordination
with international projects have documented and quantified changes in tropical
and subtropical land cover, such as the loss of tropical forest in Brazil.
Changes in land cover and land use are occurring around the world at an
increasingly rapid rate, driven largely by human activities. Research has
documented that changes in land cover such as the conversion of forest
to pasture in the tropics, and changes in land use such as increases in
fertilizer applications to cropland worldwide, are contributing to changes
in atmospheric composition and may also contribute to climate change on
both regional and global scales.
The real significance of all these scientific developments is seen most
clearly when they are taken together. Several major environmental processes
are now understood and there is some degree of predictability in their
behaviors. A deeper appreciation of how the Earth’s oceans, atmosphere,
and land surface function together as a dynamic system is being gained.
Over the next decade, the causes and consequences of an entire suite of
interacting large-scale environmental changes will be better understood.
The future course of such changes, and the limitations of prediction, will
become clearer. Scientific knowledge will improve the preservation and
enhancement of environmental quality and the management of environmental
Achieving this vision requires new science findings and better assessment
and interpretation of scientific information. The full spectrum of public
and private-sector decisionmakers also need routine, reliable, and readily
understood scientific insight.
to the Year 2010
United States and other nations face an emerging group of environmental
problems that are relatively new to public and private-sector institutions.
The global reach of such problems means that collective actions are necessary.
Yet the interlinked issues of climate change, loss of biodiversity, and
land-use and land-cover changes are not only global issues; they present
long-term challenges at local and regional scales as well.
Science has much to contribute to the management of these issues. Longstanding
climate-related problems (e.g., droughts, floods, reduced agricultural
production, and pest infestations) now can be anticipated to some extent.
Better understanding of the complexity of changes on planet Earth, such
as temperature and precipitation patterns, creates opportunities to reduce
exposure and enhance resiliency in socioeconomic systems.
Estimating in advance the magnitude of these problems or the value of opportunities
to respond is extremely difficult. One thing is already clear, however
— current economic measurements alone do not suffice to explain or judge
the severity of such problems. The importance of some issues far outstrips
any purely economic measurement. Some representative examples:
Societal Costs and
Impacts of the El Niño: In any given year, the effects
of weather and climate result in societal costs. Climate anomalies of the
past two years, most directly related to El Niño, have accounted
for worldwide impacts exceeding $30 billion. Inclusion of impacts related
to the recent flooding in China, which is believed to be partially attributable
to the 1997-98 El Niño, could push these direct losses to $60 billion.
This most recent El Niño also claimed 21,000 lives, displaced 4.5
million people, and affected 82 million acres of land through severe flood,
drought, and fire. Costs from the El Niño in terms of slowed development
and lost opportunities have yet to be measured, but surely involve economic
losses even higher than the direct costs. Early estimates of the value
of preparedness in areas such as California and Peru suggest that perhaps
one-half of the likely cost in the absence of any advance warning was avoided
in 1997-98. These limited successes were based on experimental predictions
that can be further improved. When regional summer climate perturbations
are better understood and projected, the severe impacts of events like
1998's multi-billion-dollar U.S. drought or the tenfold-more-expensive
floods in China might be ameliorated -- any reduction in their impacts
would be a noteworthy improvement. The knowledge of how to avert disaster
through forecasting, make advance preparations, and use early warning systems
effectively now appear to be within reach scientifically.
economic value of the understanding gained through the USGCRP cannot be
accurately calculated, both because of limitations in current economic
methodology and lack of accurate data. It is clear, however, that the total
value is significant (on the order of tens of billions of dollars annually).
Part of the USGCRP research plan is to improve the ability to document
the economic values of USGCRP research and applications, and thus to be
able to include such estimates as an input in the research planning process.
Patterns of Change in the Frequencies of Hurricanes:
Over the next decade, it will likely become known whether the recent epoch
(nearly 30 years) of infrequent hurricane landfalls along the East Coast
of the United States — during which time we have greatly increased our
vulnerability by building in coastal regions — has been supplanted by a
return to conditions similar to those of the 1930s, 1940s, and 1950s. In
that event, it is much more likely that the long-feared "category 4" (132-155
mph, such as the unnamed 1947 storm that hit southeast Florida and Louisiana)
or "category 5" hurricane (156+ mph, such as the 1935 Florida Keys storm)
will make landfall in a densely populated area by 2010. The losses to the
insurance industry from such an event, or the cumulative impact of more
frequent category 2 and 3 events, could render privately funded insurance
unavailable, perhaps even bankrupting a large portion of the industry.
Studies of a category 4 hurricane that passed through Florida and Alabama
in 1926 indicate that the same hurricane today would cause an estimated
$77 billion in damage. The economic and societal value of supplying constantly
improving information that could enable the industry to remain viable is
still unknown. This value could be substantial; that the industry itself
is investing in some research on this subject indicates its high level
of concern. Such information will allow U.S. Government decisionmakers
to assess more reliably whether or not to become the default insurer. Some,
but not much, of the needed information is available now. Again, much more
relevant information is believed to be within reach scientifically with
a sufficient research effort.
Issues of Fresh Water Availability:
scientists commonly identify limited availability of fresh water, a resource
many of us take for granted in the United States, as potentially one of
the most pervasive crises of the coming century. Setting aside the question
of whether certain countries may have gone to war over water by 2010, how
will things look politically and economically in the American West? Tension
between states and localities will have reached acute levels if the climate
system continues to exacerbate problems such as the diminished Colorado
River runoff. (The Ogallala Aquifer in the Texas High Plains offers an
example of affected populations already having to adjust to changes in
the water balance.) Is the West’s water supply sufficient to meet future
needs? In the fastest growing areas of the West the demand for water for
all uses already exceeds supply. What, then, will a knowledge of nature’s
tendency to sustain or hinder development in the West ultimately be worth?
Insights provided by studies of the historical impacts of climate on water
and agricultural resources, and emerging from current research efforts,
indicate that this problem could prove to be extremely costly. For example,
under current conditions, it is estimated that droughts cost, on the average,
$6 billion to $8 billion annually within the United States. Thus, advances
in current understanding of these and recent multi-billion-dollar droughts
(such as the 1987-1992 events in the West and the 1995-1996 event in Texas)
may lead to improvements worth up to a billion dollars annually.
Influences of Sources and Sinks
for Carbon on the Earth’s Climate: By 2010, scientists throughout the
world will be producing regional maps of large carbon sources and sinks.
In all likelihood, managed terrestrial ecosystems (e.g., replanted forests)
will have been shown to be an important multi-decadal sink. By 2010, the
United States may well have been confirmed and shown conclusively to possess
such a sink and to have the capacity to augment it, again subject to major
social forces pro and con. The gradual realization by governments of the
full implications of these regional maps of carbon sources and sinks cannot
help but alter the terms of the debate about emission controls. If the
scientific effort is integrated across ocean, land, and air and managed
effectively, it can demonstrate to the world that an adequate monitoring
effort is feasible and that regional mitigation and sequestration can be
made a serious part of the international negotiations. This invaluable
information seems well within reach of the research effort which is already
organizing to do the job.
The Influence of Climate Change
on the Salmon Fishery: In the United States, renewal licensing of major
dams constructed decades ago has become a serious issue, in part because
of the ecological consequences of their presence. The USGCRP has helped
to clarify the relationship of climate-related regional variations in salmon
productivity on timescales of a few decades to overall observed decline
in the Columbia River and other Pacific Northwest river ecosystems. Many
other insights about the coupling of the Earth’s major ecological systems
to climate variability and change will result from the proposed research
effort. The availability and timeliness of these insights will rest very
much on the kind of research program assembled. This program can provide
relevant information not only about the freshwater resource on which the
dams and the fish depend, but a far more complete picture of the true natural
background against which the effects of the dams can be judged.
Changes in Air Quality: The
combination of population growth and industrialization of developing countries,
notably in South and East Asia, is leading to dramatically reduced air
quality in these regions on a large spatial scale. Plumes of polluted air
are being transported out into previously unpolluted regions and at some
times reach the coastal regions of the United States (in particular the
West Coast), affecting the background concentrations of ozone and other
species important for air quality in some regions. New satellite instruments
for measuring tropospheric ozone will show clearly the spatial extent of
these plumes and their day-to-day variation. Governments in these developing
countries will begin to realize that they must take steps to control local
pollution, including reduction of fossil fuel combustion, switching to
less polluting fuels (e.g., from high-sulfur coal to petroleum products
containing less sulfur), and importing of emissions control technologies.
Such steps offer the potential to reduce greenhouse gas emissions and emissions
of air pollutants at the same time. Results obtained from the USGCRP on
global tropospheric chemistry will allow U.S. policymakers to understand
better the sources of polluted air and the regional and global impact of
these emissions and their changes.
Changes in Ozone Concentrations in the Atmosphere: The
Montreal Protocol will continue to lead to reductions in concentrations
of some ozone-destroying gases in the atmosphere in the early part of the
21st century. Many of the "quick fixes" called for under the Protocol (e.g.,
reduction of methyl chloroform) already will have taken place, and halogen
concentrations will have begun to decrease very slowly, based on the natural
lifetimes for CFCs, which are more than 100 years for some compounds. Monitoring
by the USGCRP of surface-level concentrations of CFCs, their replacements,
and related halogenated hydrocarbons is helping to assess international
compliance with the Protocol, and may help provide information on the regional
distribution of emissions of any regulated compounds. The response of the
ozone layer to these reduced levels of CFCs and related compounds is studied
routinely by USGCRP agencies with a combination of ground-, balloon-, and
space-based instruments. These measurements and associated modeling efforts
will continue to help demonstrate whether the "replenishment" of the ozone
layer is occurring, as is expected, as anthropogenically amplified stratospheric
chlorine levels decrease — or, alternatively, whether other processes (such
as stratospheric cooling associated with increased greenhouse gas concentrations
or increasing levels of stratospheric bromine) are interfering with the
expected recovery by creating conditions under which lower amounts of chlorine
can still deplete stratospheric ozone.