Over the past several years, temperatures around the world kept rising. Sometimes it's unbearable for people on this planet. "The temperature during an eight-day heat wave in Chicago in July 1995 hovered around 100 degrees Fahrenheit. High levels of humidity made the air feel even hotter, creating an almost unbearable and, ultimately, fatal environment. 556 number of deaths was attributed to the heat, which struck the elderly" ("Issues and Controversies: Global Warming "). Until human populations soared and began burning fossil fuels, greenhouse gases remained in relative balance. This affected climates to produce ice ages and heat waves that were the result of natural variation caused by sudden fluctuations in the sun's emission of radiation, volcanic eruptions and other affects. Also an increase in sea levels has forced shoreline residents to move. "A study published in the March 7 issue of the journal Science provided evidence that the disintegration of polar ice shelves led to the rapid advance of polar glaciers. The study examined the 1995 breakup of the Larsen A Antarctic ice shelf, after which five of the six glaciers behind it accelerated toward the sea. The flow of glacial ice into the oceans could cause sea levels to rise by several yards in several centuries" ("Global Environment: News in Brief "). Tornadoes, hurricanes, and other irregular weather patterns are destroying houses and farms. Irregular weather patterns also disturbed a lot of people around the world. "In the last decade of the 20th century, Earth has been plagues by a series of atmospheric disturbances. El Niño has unleashed hurricanes and droughts; the greenhouse effect is blamed for rising temperatures; and the thinning of the ozone layer might lead to an increase in skin cancer among humans" ("Today's Science: Global Warming and Ozone Hole Linked "). Frequent heat waves, irregular weather patterns, sea levels rising, and extinction of endangered animals are some of the consequences of a major problem.