The Global Change Research Program

The Global Change Research Program

by John L. Roeder

I first learned about the threat of enhanced global warming from carbon dioxide produced by fossil fuel combustion when I worked on a unit on this topic for NSTA's Project for an Energy Enriched Curriculum in 1979. Ten years later the U.S. federal government realized the significance of this and other threatened environmental changes, and the U.S. Global Change Research Program (USGCRP) was established to "combine and coordinate the research and policy development interests of 15 departments and agencies of the U.S. Government and Executive Offices of the President." Coordinating efforts of the Departments of Agriculture, Commerce, Defense, Energy, Health and Human Services, Interior, and Transportation, the Environmental Protection Agency, National Aeronautics and Space Administration, National Science Foundation, Smithsonian Institution, and Tennessee Valley Authority, it is "organized under the auspices of the Subcommittee on Global Change Research . . . one of the seven environmental issue subcommittees established by the Committee on Environment and Natural Resources . . . one of the 9 committees organized under the National Science and Technology Council" (described in our Fall 1994 issue).
To disseminate information about its efforts, the USGCRP has set up Information Offices in Washington, DC, and Michigan (2250 Pierce Road, University Center, MI 48710, (517)-797-2730, FAX: (517)-797-2622, E-mail help@gcrio.org) and has established a web site (http://www.gcrio.org). Among the documents regularly issued is a series entitled Our Changing Planet, a supplement to the federal budget and therefore addressed to members of Congress in a very attractive package subtitled "An Investment in Science for the Nation's Future.". As explained in the FY 1997 volume of this series, a USGRP internal review and a 1995 external review by the National Research Council recommended "focus on priority issues in four mature areas of Earth system science that are of great scientific and practical importance." These four areas are "Seasonal to Interannual Climate Variability," "Climate Change Over Decades to Centuries," "Changes in Ozone, UV Radiation, and Atmospheric Chemistry," and "Changes in Land Cover and in Terrestrial and Aquatic Ecosystems."
Each of these four areas is a classic example of scientific methodology. First data must be gathered -- temperature, precipitation, atmospheric constituents such as ozone, volatile organics, nitrogen oxides, sulfur oxides, chlorine, ocean circulation, and land use -- a lot of data, mostly from satellites in NASA's "Mission to Planet Earth" program (described on page 44, Fall 1994 issue). Models are constructed to analyze these data, to make predictions, and apply them for the benefit of humankind. The primary model for studying climate variability is ENSO, El Ni–o and its atmospheric counterpart, the Southern Oscillation, and the coupling of this system to other determinants of climate. The models for studying climate change are Climate System Models, the most advanced of which is at the National Center for Atmospheric Research in Boulder, CO. (Two years ago, this model was able to partition the atmosphere into "cells" of space-time with a square base 500 km on a side, a height of 1.5 km, and a time of 1 hour, and the 16 May 1997 issue of Science reports that it could compute for 300 years without drifting more than 0.5 degrees Celsius in average temperature, thus reflecting accurately three centuries of the past when there were no major atmospheric changes as have been wrought since the Industrial Revolution.) For atmospheric chemistry the model is that of the interaction and migration of molecular species in the troposphere and the stratosphere; and for land cover and ecosystems it is the connection between global warming and land habitability.
In addition to focusing on the "four mature areas of Earth system science," the past three issues of Our Changing Planet (for FY 1996, FY 1997, and FY 1998) also discuss integrative and cooperative efforts, such as those between governmental agencies and among the governments of the world. Perhaps the foremost international cooperation supported by the USGCRP is the IPCC (Intergovernmental Panel on Climate Change), jointly established by the World Meteorological Organization and the United Nations Environment Programme in 1988. Although the conclusion of the IPCC's Second Assessment Report in 1995 that "there is a discernible human influence on global climate" brought forth a storm of criticism from industry (as reported on p. 31 of our Winter 1997 issue) and is still regarded by some climate modelers as obscuring the uncertainty which still belies climate prediction (R. A. Kerr, Science, 276, 1040 (16 May 97)), it is printed without adverse comment with all the other "Key Findings of the IPCC Second Assessment Report" in the FY 1997 volume of Our Changing Planet (Resource #6, Winter 1997 issue). Unfortunately, all the attention devoted to this one conclusion overshadowed the others. For readers who may not have seen the entirety of these recommendations and wish to use them in their teaching, we reprint them here (see box).
Also of possible interest to teachers are some of the tidbits of information related to the "four mature areas of Earth system science" in the past three issues of Our Changing Planet:
"Seasonal to Interannual Climate Variability"

. . .in some regions of the globe, seasonal to interannual variations of atmospheric conditions can be predicted up to two years in advance.
The U.S. Government is now issuing, on a monthly basis, the first-ever year-in-advance forecasts of seasonal mean temperature and precipitation for the United States.
Medical research has linked changes in the incidence of diseases carried by mosquitoes and rodents with changes in temperature, rainfall, and the patterns of extreme climatic variations associated with El Ni–o events.
. . .the 1992-93 El Ni–o event reduced the 'normal' (non-El Ni–o) carbon dioxide release to the atmosphere from this region of the ocean by more than 50 percent.
TOGA [Tropical Ocean-Global Atmosphere program] developed a number of coupled ocean-atmosphere models, one of which successfully forecasted the El Ni–os of 1986-87 and 1991-92 more than a year in advance. . . . TOGA researchers began distributing experimental forecast products to a number of tropical countries . . . . Peruvians have been able to sustain the gross output of their agricultural sector, increasing it by 3% in 1987 in spite of the moderate 1986-87 ENSO event (in contrast to a 14% decrease in 1983, which accompanied the devastating 1982-83 event.
"Climate Change Over Decades to Centuries"

The newer climate models, which include the effects of . . . aerosols, predict that they are exerting a cooling influence on global temperatures.
Natural biological and physical processes, such as photosynthesis and oceanic uptake, are able to limit the annual increase in the atmospheric loading of CO2 to just under half the annual emissions of CO2. . . . How long will these elevated removal rates continue?
"Changes in Ozone, UV Radiation, and Atmospheric Chemistry"

Human initiated biomass burning is estimated to be a significant source of the emissions of methyl bromide globally. . . .a bromine atom is about 40 times as efficient as a chlorine atom in destroying stratospheric ozone. . . .
. . .the Ozone Depletion Potential (ODP) of HFC-134a is very small. . . .
. . .emissions of chlorofluorocarbons (CFCs from human activities have been unambiguously identified as the causes of the Antarctic ozone hole. [To this was added in FY 1998 "and the hydrochlorofluorocarbons (HCFCs)," once regarded as an alternative to CFCs.]
Stratospheric ozone depletion is now understood to introduce a cooling tendency in the climate system.
. . .at 45o N latitude . . . springtime exposure to DNA-damaging and erythemal (sunburn-inducing) radiation is calculated to have increased by 8.65 and 5.1% per decade, respectively, for the past 2 decades.
"Changes in Land Cover and in Terrestrial and Aquatic Ecosystems"

The decline in snow cover extent in the Northern Hemisphere by about 10 percent over the past 20 years has resulted in . . . decrease in Arctic sea ice . . . melting of alpine glaciers . . . rise of sea level.
Sea level is suggested to have risen 10 to 25 centimeters (cm) this century, of which about 1 cm (range -5 cm to +7 cm) may have been due to the direct effects of humans in changing land use.
Oceanographic observations along the central North Atlantic have revealed a distinct warming in the upper 2500 meters over the past 35 years.
. . .the far-northern climate has warmed by roughly 2oC since the 1880s . . . tree growth at first accelerated . . . but then flattened, even though the climate continued to warm . . . the most recent decades of warming . . . may be stressing northern forests by speeding up moisture loss and perhaps subjecting them to more frequent insect attacks. . . .
. . .elevated CO2 concentrations may, for selected species, mitigate the damaging effects of elevated ozone (O3) concentrations. However some species, such as aspens, become more sensitive to increased concentrations of O3 if CO2 concentrations are elevated.
. . .soil carbon losses from intensive farming systems can be reversed through changes in farming technology.
. . .as much as 30% of the deforested [Amazon rain forest] land is in some stage of secondary succession.
Conversion of natural tropical forests to farm and ranch land has the potential to increase nitrous oxide (N2O) emissions from that land by as much as a factor of three. N2O is a greenhouse gas with a global warming potential per unit mass that is 120-330 times greater than CO2 over the next 100 years. . . .
. . .43 years of observations (1951-1993) along the coast of southern California indicate that the biomass of large zooplankton has decreased by 80%. . . .
Increased concentrations of atmospheric CO2 are likely to enhance productivity of major rice varieties, providing more food, but also leading to greater emissions of methane. The associated climate changes are also predicted to substantially alter the relations between major insect pests of rice and their natural predators, potentially creating significant pest management problems.
. . .global scale variations in climate alter regional patterns of rainfall and temperatures.
. . .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 croplands worldwide, are contributing to changes in atmospheric composition and may also contribute to climate change on both regional and global scales.
Precipitation is among the most important climate variables in socioeconomic terms because it affects water management and agriculture and causes floods and droughts.
Key Findings of the IPCC Second Assessment Report (as extracted in the FY 1997 Our Changing Planet)
Effects of Human Activities on Regional and Global Climate, and on Sea Level

Human activities are increasing the atmospheric concentrations of CO2 and other greenhouse gases that tend to warm the atmosphere and, in some regions, of aerosols that tend to cool the atmosphere.
The Earth's climate is changing. The surface temperature this century is as warm or warmer than any other century since at least 1400 AD; the global average surface temperature has increased by 0.3 to 0.6oC (about 0.5 to 1oF) over the last century; the last few decades have been the warmest this century; sea level has risen 10 to 25 cm (about 4 to 10 inches); and mountain glaciers have generally retreated this century.
Models that account for the observed increases in the atmospheric concentrations of greenhouse gases and sulfate aerosols are simulating the recent history of observed changes in surface temperature and its vertical distribution with increasing realism.
The balance of evidence suggests that there is a discernible human influence on global climate.
Without specific policies that reduce the growth of greenhouse gas emissions, the Earth's average surface temperature is projected to increase by about 1 to 3.5oC (about 2 to 6.5oF) by 2100 -- a rate of warming that would probably be greater than any seen in the last 10,000 years.
The reliability of regional-scale predictions is still low, and the degree to which climate variability may change is uncertain.
Sea level is projected to rise by 15 to 95 cm (6 to 38 inches) by 2100.
The long atmospheric lifetime of many greenhouse gases, coupled with the thermal inertia of the oceans, means that the warming effect of anthropogenic emissions will be long-lived.
Even after a hypothetical stabilization of greenhouse gas concentrations, temperatures would continue to increase for several decades, and sea level would continue to rise for centuries.
Potential Health and Environmental Consequences of Climate Change

Human-induced regional and global changes in temperature, precipitation, soil moisture, and sea level add important new stresses on ecological and socioecnomic systems that are already affected by pollution, increasing resource extraction, and non-sustainable management practices.
Most systems are sensitive to both the magnitude and rate of climate change.
Many regions are likely to experience adverse effects as a result of climate change, some of which are potentially irreversible; however, effects of climate change in some regions may be beneficial.
The projected changes in climate include potentially disruptive effects that will affect the economy and the tranquility of life for this and future generations:
Human Health will be adversely affected through an increase in the rate of heat-related mortality and in the potential for the spread of vector-borne diseases such as malaria, dengue, yellow fever, and encephalitis and non-vector-borne diseases such as cholera and salmonellosis.
Food Security will be threatened in some regions of the world, especially in the tropics and subtropics where many of the world's poorest people live. On the whole, the effects of climate change over the next century on total global food production may be small to moderate in comparison to the effects of population change and demands for improved nutrition.
Water Resources will be increasingly stressed, leading to substantial economic, social, and environmental costs, especially in regions that are already water-limited and where there is strong competition among users.
Human Habitat Loss will occur in regions where small islands and coastal plan and river areas are particularly vulnerable to sea level rise.
Natural Ecosystems will be degraded because the composition, geographic distribution, and productivity of many ecosystems will shift as individual species respond to changes in climate. This may lead to reductions in biological diversity and in the goods and services ecosystems can provide for society.

Developing countries are more vulnerable than developed countries to climate change because of their socioeconomic conditions.
Impacts will be hard to quantify with certainty because of uncertainties in regional climate projections, the complicating effects of multiple stresses, and a lack of understanding of some key processes.
Approaches to Mitigate or Adapt to Climate Change

Adaptation -- which involves adjustments in practices, processes, or structures of systems -- can be helpful in reducing adverse impacts or in preparing to take advantage of potential beneficial changes in climate.
Successful adaptation will depend upon education, technological advances, institutional arrangements, availability of financing, technology transfer, information exchange, and incorporation of climate change concerns into resource-use and development decisions. Potential adaptation options for many developing countries are extremely limited due to the limited availability of technological, economic, and societal capabilities.
Options such as migration corridors to assist adaptation of natural ecosystems to new climate conditions are, however, currently limited and their effectiveness is generally unproven.
Stabilization of the atmospheric concentrations of CO2 at three times the pre-industrial concentration or less will eventually require human-induced emissions of greenhouse gases to be cut below today's levels.
Gains in energy efficiency of 10-30% above present levels are feasible at little or no cost in many parts of the world through technical conservation measures and improvement management practices over the next 2 or 3 decades.
Significant reductions in net greenhouse gas emissions can be achieved utilizing an extensive array of technologies, and policy measures that accelerate technology development, diffusion, and transfer in all sectors.
Flexible, cost-effective policies relying on economic incentives and instruments, as well as internationlly coordinated instruments, can considerably reduce mitigation and adaption costs.

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