In June the U.S. Environmental Protection Agency released a report linking global temperature changes to modern society’s emissions of such products as carbon dioxide. The report set off another round of frenzied questioning and editorializing in the national media about “greenhouse gases.”
This month’s column looks at that debate and what it could mean for electricity users.
The greenhouse gases at the center of the debate are mostly water vapor (H20) and carbon dioxide (CO2).
These gases let sunshine filter down to the Earth’s surface, says University of Kentucky Agricultural Meteorologist Tom Priddy. But when that sunlight bounces off the Earth’s surface, its wavelength changes in such a way that the greenhouse gases block it from escaping back into outer space, trapping the energy near the surface.
It’s called the greenhouse effect because the same thing happens on a smaller scale in a greenhouse. But instead of a glass roof and walls holding in the sunshine and heat, the Earth’s atmosphere works as a gaseous roof and walls for the entire planet.
“That’s a positive thing,” Priddy explains. “If we didn’t have that layer of greenhouse gases the Earth’s surface would be anywhere from 50 to 100 degrees Fahrenheit colder.”
Scientists believe that increasing or decreasing the greenhouse gases affects the heat balance on Earth. Indeed, atmospheric conditions and levels of carbon dioxide have fluctuated over enormous periods of time. Probable causes for these historic changes are Earth’s distance from the sun and differences in the mix of plant and animal life.
Making sense of temperature changes and carbon dioxide percentages is where the greenhouse gas discussion gets complicated. Mix statistics with scientific speculation and differing political views and you soon reach the emotional level of basketball fans arguing about their favorite players. But in the greenhouse gas match-up, far more than a game score is at stake. How the greenhouse gas issue gets resolved could affect the cost and availability of electricity, as well as many other goods and services.
How did an area of scientific inquiry change into a political issue with such far-reaching economic implications?
It helps to return to some basic science.
Carbon dioxide occurs naturally in the atmosphere. Animals breathe in oxygen and exhale CO2, while plants breathe in CO2 and exhale oxygen. Burning coal, oil, or wood uses oxygen and produces carbon dioxide.
Before the industrial revolution in the late 1700s, scientists figure atmospheric carbon dioxide levels were about 280 parts per million by volume (ppmv). Today’s levels are about 370 ppmv, about one-third higher. Some predictions put carbon dioxide levels at double the pre-industrial revolution level by the year 2065.
A lot’s changed during the past 200 years. An ever-growing number of humans have altered the environment to their own purposes, changing the mix of plants and animals, while burning fossil fuels in cars, factories, and power plants.
Measuring air temperatures during that time has seen a tremendous increase in accuracy and volume of data. In the early days of the country, when most people lived along the eastern seaboard, thermometers were few and far between. Today, every county from the Atlantic to the Pacific boasts a weather station. Globally, new devices are being used to monitor temperatures over the oceans.
At the local and regional level all these improvements in measuring temperatures show that the weather fluctuates from one extreme to another in complex ways. But concluding that we’re seeing long-term climate changes bothers Priddy.
“Global climate models have only recently begun to include the oceans as well as the atmosphere,” says Priddy. “The possibility exists that what we’re seeing now, with temperatures going up in certain places, is just normal variation.”
While cautious weather and climate scientists continue to fine-tune their research, the more sensational findings and predictions of global warming get into the headlines–and that’s where varying political views meet practical reality.
The release of carbon dioxide into the atmosphere by burning coal to generate electricity has become a focal point in the already complex debate about what could–or should–be regulated.
One focus of the debate is a United Nations proposal worked out in 1997 in Kyoto, Japan. That plan called for reducing greenhouse emissions below 1990 levels over several years.
Last year the United States rejected what is called the Kyoto Protocol, citing one scientific tenet and two fears. The scientific argument was that there was no link between global warming and society’s production of greenhouse gases. The fears were that the agreement would take away some of our rights to make our own energy policy, and that the Kyoto reductions would seriously damage the economy.
The release of the EPA report this summer represents a change in attitude toward the science part of the debate, officially acknowledging that human activity is changing the composition of the Earth’s atmosphere. But the fears about political and economic consequences remain.
And yet even as the Bush administration continues to oppose the Kyoto agreement, international pressure to act continues to mount. Already ratified by Japan and the European Union, Russia’s widely expected ratification before year’s end could mark the minimum worldwide requirement of 55 percent. That would start implementation of the Kyoto Protocol. Even though the treaty has not been presented to the U.S. Senate for ratification, individual senators may try to introduce legislation duplicating its terms to force the issue.
Where does that leave electrical utilities–and electric cooperatives–as President Bush pursues his Global Climate Change Initiative that favors voluntary steps and modest financial incentives?
Glenn English, chief executive officer of the National Rural Electric Cooperative Association, says that most utilities concede that stricter regulations on carbon dioxide and greenhouse gas emissions are inevitable. Therefore, electric utilities, including co-ops, must include CO2 as part of their long-term emissions plans. It’s a case of voluntarily creating guidelines and policies now, before someone else does it later.
For more info on climate change, visit these Web sites: www.epa.gov/globalwarming/ publications/car and
(scroll to the bottom for the section with links on Global Warming Debate, and note there is no punctuation after the three w’s in this Internet address).
Next month: How to control greenhouse gases