IMPACTS OF CLIMATE CHANGE

  • Budyko (1986) has estimated that the global mean surface air temperature reached a maximum of 25.5oC during the Lower Carboniferous period. This temperature was 10.6oC higher than at present (Budyko, 1986). Other figures show that a doubling of the current atmospheric carbon dioxide concentration will increase mean global air surface temperature by about 1.5-4.5,oC with the best estimate at 2.5oC (Budyko, 1986; IPCC, 1996a).

  • The major effects of global warming are the melting of the polar icecaps, oceanic water expansion, and the resulting rise in global mean sea level. Global mean sea level has risen by 10-25 cm over the past 100 years (IPCC, 1996a). It is likely that this rise has been due largely to the concurrent increase in global mean surface air temperature (IPCC, 1996a). Calculations show that complete melting of the polar icecaps will raise the global mean sea level by about 81 m (IPCC, 1996a). Other effects such as regional climatic changes and the possible intensification of climatic phenomena such as the El Ni\~no Southern Oscillation are still the subject of research.

  • Most of the anthropogenic increase in carbon dioxide is due to the combustion of fossil fuels to generate electricity and to power internal combustion engines. In the past one hundred years, the number of vehicles (automobiles and trucks) throughout the world has increased steadily, reaching a level of 629 million for the 48 countries with at least one million passenger cars (World Road Statistics, 1996). As economic development continues to take place, it is very likely that the number of vehicles will continue to increase, compounding global climate change. Thus, coping with global climate change will require, at the very least, that human societies reassess their relationship with the internal combustion engine.

  • In the recent United Nations Climate Change Conference in Kyoto (1997), the United States agreed to reduce its emissions of greenhouse gases by 7 percent (below 1990 levels) by the year 2012. To be binding, this international agreement needs to be ratified by the U.S. Senate. Given the current political climate, it remains uncertain when this ratification will take place.



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