Editor's Note: From time to time, IOWATCH will replace the usual Faculty Focus column with a description of student activities. Training students in the interdisciplinary mode of thinking required for addressing global change issues remains a major goal at CGRER. Most of this effort is directed toward graduate and undergraduate students in the natural sciences and engineering. However, occasionally a younger student is enlisted in CGRER's ranks.
During the summer of 1994, intern Renee Hurtig performed library research in government policies dealing with greenhouse gases. Renee, newly graduated from City High in Iowa City, became interested in this field through high school debate. Now a freshman at Duke University, Renee plans to major in public policy. She summarized her internship investigations in the following article:
Imagine going into the greenhouse of your local plant store and permanently raising the temperature several degrees. Understandably, the owners would be furious -- thousands of dollars of plants would wither, suffer, and die, and the owners' livelihood would be wiped out. The financial losses would hinder their ability to provide food and shelter for their families. Now translate that scenario into one involving billions of people and it's easy to see why many people are concerned about the potential for global warming.
Global warming is attributed to the magnification of a phenomenon known as the greenhouse effect. Like a greenhouse's glass panels, the Earth's atmosphere allows sunlight to filter through and heat the planet's surface. The Earth sends back much of that heat in the form of infrared radiation, yet not all of it escapes. Greenhouse gases, such as CO2, water vapor, and ozone, trap some of this heat and send it back to the surface, adding to the warming effect of sunlight. Without this natural trapping effect, the average global temperature would drop approximately 60F.
A continual rise in the concentration of CO2 in the atmosphere since the start of the Industrial Revolution has magnified the greenhouse effect. Coincidentally, global temperatures have risen slightly, but the warming is within the annual variability that might be expected. Some scientists attribute that rise in temperature to the emission of CO2 from increased burning of fossil fuels such as coal, combined with the destruction of forests and vegetation, which absorb some of the excess CO2. Carbon dioxide emissions have more than tripled since 1950,2 while at the current rate of deforestation, the world's tropical rain forests, one of the largest known storers of CO2, will all but disappear by midway into the 21st century.3 Some experts predict that CO2 concentrations in the atmosphere will double by that time.
The United States is the world's largest CO2 emitter, followed by China and Russia. In 1993, approximately 5,900 million tons of CO2 were emitted by all countries from fossil fuel burning -- 68% of which was from the industrial world and former Soviet Bloc, although those countries have only 22% of the world's population.2 The United States leads the world in per capita emissions of CO2, with 5.4 metric tons of carbon,2 and Iowa ranks thirteenth among states in this category.
As a result of the magnification of the greenhouse effect, it has been estimated that global temperatures could rise 2 to 5 F. The Intergovernmental Panel on Climate Change estimated that global temperatures could rise as high as 19 C by 2050 if CO2 concentrations double.2 The expected climate change would be of a magnitude similar to the difference between today's climate and that of the last Ice Age. In a worst-case scenario, this warming could lead to the melting of the polar ice caps, raising sea levels and dramatically altering coastlines, while also disrupting and potentially destroying the world's already-limited supply of fresh water. However, all of these predictions are highly uncertain.
It may be hard to believe that a few degrees of temperature change could have such dire consequences. Yet in Iowa, the possible impacts of global warming on crop production are grave enough to hit home. While average temperatures for the five-year period ending in March, 1991, increased by only a fraction of a degree over those of the mid-1950s, the average temperatures during the summer growing season were at record levels for the last three years in that period. Using NASA's models, researchers at Michigan State University predicted that the average growing season temperature in Des Moines would be 6.3 to 14.4 F warmer if CO2 levels are doubled, with no substantial change in the amount of precipitation. Crop failures and food shortages could become commonplace.5 Farmers would need to respond with different crop types and new farming techniques, and seed companies would need to develop new genetically adapted varieties.
To reverse this trend and stabilize CO2 concentrations in the atmosphere, CO2 emissions would have to be cut 60%.
The global implications of the greenhouse effect have attracted international attention. The Earth Summit, held in Rio de Janeiro in June, 1992, produced a number of agreements that dealt with global warming on some level. Agenda 21, a forty-chapter document of programs and cost estimates, outlined goals and an action plan for promoting environmentally and economically sustainable development, especially in industrializing countries. Individual chapters dealt with combating climate change and preventing deforestation.
Also accepted in conjunction with the Rio conference was the Convention on Climate Change. The goal of the convention was to "... achieve ... stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened, and to enable economic development to proceed in a sustainable manner."6 The convention requires industrialized countries to develop national emission standards and inventories and to report on their progress, but no specific targets or dates are included other than the aim of returning greenhouse gases to "earlier levels" by the year 2000. To fulfill the goals and requirements of the convention, President Bill Clinton and Vice President Al Gore proposed their Climate Change Action Plan in October, 1993.7 The Clinton-Gore plan intends to reduce U.S. greenhouse gas emissions to 1990 levels by the year 2000 through initiatives in all sectors of the economy -- industry, transportation, homes, office buildings, forestry, and agriculture. Actions in each of these sectors are designed to increase the markets for greenhouse gas emission-reducing technology, including alternative energy sources such as wind and solar power, while protecting forests through increased recycling, better forest management, and more tree planting. Few of these plans were implemented as of the summer of 1994.
Currently, no national government laws or programs exist that intentionally and directly address greenhouse gas emissions in the United States. The Clean Air Act of 1990 focused mostly on urban smog, acid rain, and air quality. The act targets 189 pollutants, ranging from freon, used in refrigerators and air-conditioners, to hydrocarbon ethanol, a yeast by-product produced in large quantities by bread bakeries, whose emissions must be cut by 90%. It also sets regional air quality standards and emission levels and fees for many pollutants.
One section of the Clean Air Act that does address greenhouse gas emissions has a direct impact on Iowa. The act requires that the smoggiest areas of the country begin using cleaner-burning "reformulated" gasoline that is 2% oxygen by weight by 1995. On June 30, 1994, the U.S. Environmental Protection Agency ruled that 30% of the oxygenates added to the gasoline to meet the standard must be made from a renewable source. Ethanol, an oxygenate made from corn, is the only product that could meet the expected demand when the new gasoline hits the pumps.10 Iowa is the second largest producer of ethanol in the country, producing almost five times as much as the third largest producer, Indiana.
This requirement is controversial in two respects. First of all, conflicting reports about the environmental and economic benefits of ethanol, compared to its fossil fuel based alternative methanol, have been given by the U.S. Environmental Protection Agency and the U.S. Department of Agriculture. Second, the oil industry, the primary distributor of methanol in this country, is suing the government over this decision.
On the state government level, the Energy Efficiency Act of 1990 required Iowa utilities to spend 2% of their electric energy revenues and 1.5% of their natural gas energy revenues on energy efficiency programs. Iowans use more energy per capita than residents of forty other states, and most of this energy is generated by CO2-producing methods such as burning fossil fuels.5 A 1989 study for the Iowa Utilities Board concluded that "the net benefit to Iowa on efficiency investments of $39 million to $52 million could range from $89 million to $205 million, making energy efficiency the most economically attractive source of energy supply."12 The efficiency plans must include programs such as giving rebates on efficient appliances and light bulbs, and tree-planting.
Our behavior can affect ecosystems and climates -- from those of the small world of a local greenhouse to those of the Earth. Vice President Al Gore acknowledged the need for people to recognize the scope and impact of their actions when he wrote: Human civilization is now the dominant cause of change in the global environment. Yet we resist this truth and find it hard to imagine that our effect on the earth must now be measured by the same yardstick used to calculate the strength of the moon's pull on the oceans or the force of the wind against the mountains. And if we are now capable of changing something so basic as the relationship between the earth and the sun, surely we must acknowledge a new responsibility to use that power wisely and with appropriate restraint. (3)