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(Nobel Laureate in Chemistry, 1995, Professor at University of California, Irvine, Foreign Secretary for the National Academy of Sciences, Past President of the American Association for the Advancement of Science)
In 1995, Sherwood Rowland, along with two of his colleagues, won the Nobel Prize in Chemistry for pioneering research in atmospheric chemistry of the destruction of the ozone layer. Since receiving his Ph.D. from the University of Chicago in 1952, he has climbed the academic ranks in chemistry, and is currently the Donald Bren Research Professor of Chemistry and Earth System Science at the University of California at Irvine. Dr. Rowland has received many awards including the Roger Revelle Medal from the A merican Geophysical Union. He also currently serves as the Foreign Secretary of the National Academy of Sciences, and is a former President and Chairman of the Board of the American Association for the Advancement of Science.
Mr. President and Mr. Vice President, global climatic change is underway. Carbon dioxide from the combustion of coal, oil, and natural gas has risen 15 percent in the atmosphere since 1958. Methane, some of which is emitted from cattle and rice paddies, h
as increased 16 percent since 1978. The air now holds four times as much chlorofluorocarbons as it did 25 years ago. The amount of ozone in the stratosphere over the United States is 6 to 10 percent lower than it was in the 1960s.
Many other changes are occurring as well. The global average surface temperature has risen about 1 °F during the past century, and sea level has risen from 4 to 10 inches.
Land use patterns have been greatly altered as forests are burned for use as agricultural land. Many of the species formerly in these forests are disappearing. The geographical ranges of tropical diseases are moving northward. Human activities are the chi ef cause of many of these changes. The last century saw tremendous growth in the global population, from about 1H billion in 1900 to 6 billion in the year 2,000 and 8 billion in the year 2025. Much of the world is now moving as fast as possible into a mor e affluent, energy-intensive era.
The combination of a rapidly growing world population with an increase in per capita use of energy carries with it great pressures on the environment and the atmosphere. Because the wind circles the earth within a few weeks, greenhouse gases emitted from each country quickly become a global problem requiring a global solution. During the 1990s, the world called upon its scientists to evaluate the question of global warming from the accumulation of greenhouse gases. The authoritative IPCC has estimated a probable increase in g lobal surface air temperature of about 3H °F by the year 2100, with a possible range from 2 to 6H °F. They further stated that the balance of the evidence suggests a discernible human influence on global climate, and warned that the average rate of warmin g will probably be greater than any experienced in the past 10,000 years. The variation in estimated outcomes depends upon what the countries of the world do to control the emissions of carbon dioxide and other greenhouse gases in the intervening years. M ore than 2600 scientists have now signed a statement on global climatic disruption in which, as scientists and as concerned citizens, we ask that the United States demonstrate strong leadership in the global effort with a firm proposal for reducing U.S. e missions of greenhouse gases.