global warming

Definition

Steady increase in the Earth's average lower atmosphere (near surface) temperature due to emissions and build up of greenhouse gases (see greenhouse effect). While this temperature has risen by 0.6°C in the last 140 years, it may rise from 1.5°C to over 2.0°C by the year 2070, and could completely alter climate zone patterns resulting in increased or decreased rainfall, winds, snow, and other unprecedented weather phenomenon. The rising temperature could melt the polar ice caps and cause sea levels to rise everywhere, permanently flooding many low lying parts of the earth. The temperate areas in Asia and Americas might experience crop failures due to drier and hotter conditions.