The temperature during an eight-day heat wave in Chicago, Ill. in July 1995 hovered around 100ÃÂ° Fahrenheit. High levels of humidity made the air feel even hotter, creating an almost unbearable and, ultimately, fatal environment. A total of 566 deaths were attributed to the heat, which struck the elderly and the infirm especially hard.(1,10,25)
Was the Chicago heat wave just a random occurrence? Or are July's heat wave, flooding in the Midwest in March 1995, record summer temperatures in Britain in 1995 and other severe weather events over the past few years evidence that the Earth is experiencing what scientists call the greenhouse effect?(1,4,5,9)
Some scientists in the 1970s began predicting that the increase of levels of certain types of gases in the Earth's atmosphere, likely caused by human activities such as industry and agriculture, would trap heat near the Earth's surface. Like the windowpanes of a greenhouse, the slightly transformed atmosphere would raise global temperatures (a process known as global warming), leading to a melting of the planet's ice caps, a rise in sea levels and a change in weather patterns, they claim.
Environmentalists have stressed the dire ecological and social problems that they believe could result from a global rise in temperature. They have been seeking worldwide agreements to limit emissions of greenhouse gases thought to be linked to global warming(15). Emissions limits are opposed by those who argue that the economic and social costs of such a strategy would be too high and that there is not enough evidence of global warming to merit such restrictive policies. They point to satellite data indicating that world temperatures have held steady over the past decade. (2,10)
The first warnings of global warming were dismissed by some scientists and analysts as hasty and inaccurate, and based on...