In 1961 television episode, a young woman a degree heat. The reason for her discomfort is a change in the earth's orbit, me which moving closer to the sun. At the end of ha is the television episode, the woman wakes from a dream to discover that, in fact, the earth is glo moving from the sun. This is a science away Sc fiction example of climatic change. In reality, scientific evidence suggests that there is a global warming trend, and the indisputable geologic record of ice ages indicates that the P earth's climate does change. The results of such w changes can have a tremendous impact on human life, disrupting peoples' food supplies t personal comfort, and choices of places to live. The long-term state of the atmosphere in a par- ticular location is called climate, the short-term state is called weather Weather, climate, and human activity interact and alter one another. Growing evidence indicates that the great societies of the Bronze Age collapsed because a severe dust storm brought on an extended drought, with resulting changes in climate. The Sahara Desert was once ferile and green. In the last century, the surface temperature of the earth has warmed about one degree, and a pattern of increased weather variability has been noted in