Concerns about climate change and the role of fossil fuel use

The greenhouse effect, the ability of certain gases like carbon dioxide and water vapor to effectively trap some of the reemission of solar energy by the planet, is a necessary component to life on Earth; without the greenhou se effect, the planet would be too cold to support life. However, human act ivities are increasing the concentration of carbon dioxide and several othe r greenhouse gases, resulting in concerns about warming of the earth by 1-5 degreesC over the next century. Recent increases in global averaged temper ature over the last decade already appear to be outside the normal variabil ity of temperature changes for the last thousand years. A number of differe nt analyses strongly suggest that this temperature increase is resulting fr om the increasing atmospheric concentrations of greenhouse gases, thus lend ing credence to the concerns about much larger changes in climate being pre dicted for the coming decades. It is this evidence that led the internation al scientific community through the Intergovernmental Panel on Climate Chan ge (IPCC) to conclude (after a discussion of the remaining uncertainties) " Nonetheless, the balance of the evidence suggests a human influence on glob al climate". More recent findings have further strengthened this conclusion . Computer-based models of the complex processes affecting the carbon cycle have implicated the burning of fossil fuels as a major factor in the past increase in concentrations of carbon dioxide. These models also suggest tha t, without major policy or technology changes, future concentrations of CO, will continue to increase largely as a result of fossil fuel burning. This paper reviews the current understanding of the concerns about climate chan ge and the role being played by fossil fuel use. (C) 2001 Elsevier Science B.V. All rights reserved.