U.S. News and World Report: 1. Climate change is defined as any significant variation in climate measures–precipitation, temperature, wind–for an extended period, usually decades or longer. 2. Global warming is a rise in the average temperature of Earth’s surface. 3. In order to estimate temperatures of the past, scientists analyze "proxy" indicators such as tree rings, ice cores, and ocean sediment. 4. A French mathematician, Jean Baptiste Joseph Fourier, was the first to recognize a gradual …