Carbon Dioxide and
Global Warming
     Photosynthesis. Carbon dioxide is an essential ingredient in photosynthesis.  In the cells of leaves carbon dioxide from the air mixes with water drawn from plant roots.  Charged by light from the sun, molecules in these leaves are transformed into oxygen and carbohydrates (sugars) which are the food of plants and all who feed on them.  In other words, carbon dioxide is essential to human survival.

     On alert. Certainly there are enough climatic changes around the globe to bring Earth's residents to alert. Spring 2000 in the United States was the hottest spring on record. The 1990s were the warmest decade in a millennium. There is a heat wave on the Antarctic Peninsula. Glaciers are retreating. Animal habitats are warming. The four horsemen of global warming are Thaw, Drought, Storms, and Floods. An excellent web site is http://www.pbs.org/wgbh/warming....

      The issue of debate, however, is whether we humans create too much carbon dioxide which overly insulates the earth and leads to global warming (greenhouse effect). That is, carbon dioxide and other gasses act like the glass in a greenhouse and hold in heat.  That we create carbon dioxide is beyond doubt.   Each year U.S. energy use pours about five and one-half billion tons of carbon dioxide into the atmosphere. Although the United States has 4 percent of the planet's population, it produces 25 percent or more of greenhouse gasses. An interesting history book on point is Greenhouse by Gale E. Christianson (Walker & Company, N.Y., 1999).

      Roughly three-quarters of human-caused emissions of carbon dioxide come from fossil fuel combustion and the other one-fourth comes from the burning of forests in slash-and-burn agriculture and development. The effects of carbon dioxide emissions are the subject of intense scientific examination. 

      Does-so view. Representative of the majority view that global warming results from these emissions are:  http://www.epa.gov/...   and the World Watch Institute at http://www.worldwatch.org/ and the Union of Concerned Scientists at http://www.ucsusa.org/ . A wealth of source materials can be found at http://www.globalchange.org/ .  Does-not view. The contrarian position can be found at http://www.globalwarming.org/ and at  http://www.marshall.org/.  

      Why the conflicting views? Beyond the political aspect of the global warming issue, the underlying science leads to opposing conclusions.  Why?  The principal scientific tools for studying climate change associated with greenhouse gasses are global climate models.  These are mathematical models which mimic the fluid dynamics and physics of Earth's atmosphere, oceans, and land surface. There are variations among the results and predictions produced by these models. Most models' results are plausible and defensible but doubts remain.

      Given those differences scientists from around the planet have convened to reach a consensus on greenhouse effects.  The results are published by the Intergovernmental Panel on Climate Change (IPPC). A well known and once controversial 1996 statement by the IPPC was that "the balance of evidence suggests a discernible human influence on climate." IPPC's Third Assessment in 2001 was bleaker than the earlier statement, suggesting even higher global temperatures in the decades to come.

      Kyoto agreement. At the political level in late 1997 representatives from many countries met in Kyoto, Japan, to adopt limitations on greenhouse gas emissions.

      The agreement was designed to strengthen the United Nations Framework Convention on Climate Change, which was signed by over 150 countries, including the United States, at the1992 Earth Summit in Rio de Janeiro. At Rio the most industrialized nations agreed to the voluntary aim of returning their greenhouse emissions to 1990 levels by the year 2000.

      In the Kyoto Protocol the developed nations agreed to limit their greenhouse emissions to levels emitted in 1990.  The U. S. agreed to reduce greenouse emissions from 1990 levels during the period 2008 to 2012.  Congress has not ratified the protocol.  See  http://www.eia.doe.gov/... and http://www.me3.org/... In early 2001 President Bush abandoned the Kyoto treaty and the Europeans were angry with him. His language was reminiscent of the America First stridency last prevalent in the 1980s.

     Rules to govern the Kyoto Protocol were agreed upon by 178 nations in Bonn, Germany, in July 2001. Major changes were made to ease the burden on the U.S. -- carbon "sinks" [forests] to offset emissions and emissions trading. The U.S. would not budge from its position and its delegate was booed. Fifty-five countries producing a total of 55 percent of the industrialized world's emissions must ratify the treaty for it to take force.

     Greenhouse gas producers. Americans produce almost one-fourth of gasses associated with global waming. The average Anerican consumes twice as much energy as the average European, and the emission of green house gasses is about twice as high per capita in the U.S. as in Europe.

     American coal-powered power plants pump 2.3 billion tons of carbon dioxide into the air each year, twice the amount emitted by cars.

     Prior to leaving office, President Clinton proposed regulations for the first time limiting emissions of carbon dioxide by power plants. He suggested a "cap and trade" system, under which the federal government would set a national limit on emissions, and divide pollution among the power plants. However, President Bush in early 2001 capitulated to the wishes of his political supporters and refused to regulate carbon dioxide. For the sordid details the July 22, 2001, The New York Times Magazine devoted 11 pages with big color photos. The front cover's headline in letters 1 1/2 inches tall reads: "How Coal Got Its Glow Back."

     America's greenhouse-gases policy. While there are some prominent industries voluntarily reducing emission of greenhouse gases, by and large the old paradigm prevails. Produce and pollute; it's good for business. With President Bush's cave-in to the oil, natural gas, and coal mining industries, it is hard to define America's global warming policy. The New York Times commented: "These were hasty and ill-conceived decisions that have essentially left the United States without a policy on a matter of global importance."

     Reduction. Reduction of  greenhouse gasses can be accomplished by a variety of methods.  Saving trees (increasing biomass) is being tested in Belize by The Nature Conservancy ["carbon sequestration"]. A summary of ideas is at: http://swhite.me.washington.edu/...

     The federal Department of Energy is doing research on how to cut greenhouse gas emissions and how to store carbon dioxide such as storing them as carbonates. One of its research labs is the National Energy Technology Laboratory in Morgantown. An emerging view is that the quickest way to slow global warming is not to go after carbion dioxide emissions first but to cut other heat-trapping greenhouse gasses first, such as the particle haze that accompanies the burning of fossil fuels.

Last updated on Tuesday, July 24, 2001