Greenhouse Effect

The greenhouse effect is a term used to describe the trapping of heat in the earth's atmosphere that would otherwise escape into space. A naturally occurring greenhouse effect is essential to support life on earth because some heat is needed to maintain temperatures conducive to plant and animal survival. However, too much heat that is kept within the atmosphere because it is absorbed by the so-called greenhouse gases can lead to global warming. It is this problem of escalating concentrations of greenhouses gases that is typically linked to the greenhouse effect.

Most climate scientists now believe that increasing concentrations of greenhouse gases are a significant cause of climate change and global warming, and that these increases are due in large part to human activity rather than resulting from natural climate cycles. Assessment reports of thousands of climate research studies were issued by the Intergovernmental Panel on Climate Change (IPCC) in 1990, 1995, and 2001 and indicated that greenhouse gases are increasing in concentration, that climate changes are actually occurring, and that human activity is linked conclusively with increases in carbon dioxide, the most significant greenhouse gas. Based on a growing consensus within the scientific community and growing alarm by the general public, governments have begun to institute policies and programs to reduce the growth of greenhouse gases and meet the goals found in the Kyoto Protocol.

At the same time, controversies have continued since the late 1970s about the nature of the scientific phenomenon itself and its potential environmental, social, and economic impacts. A small group of scientists and other skeptics believe that what is labeled as the greenhouse effect is part of long-term natural climate cycles or that a warming climate will not have the dire consequences that supporters of the greenhouse theory predict. They point out evidence that [Page 1033]climate changes have occurred regularly in the past without any suspected human cause, and that adaptation by plants and animals, including humans, has accounted for much of human history. The critics caution that some recommendations to address perceived climate change are unnecessary and economically inefficient because the costs of reducing greenhouse gases are high relative to the benefits achieved.