Global warming refers to a rise in the average global surface temperature over time. The opposite is global cooling, a decline of the average global surface temperature. Global warming doesn’t mean the planet’s temperature rises all at once. Some areas will be hotter, while others may get colder; however, there is an overall warming trend. Global warming is an example of a change in global climate. Atmospheric temperature data that has been collected for the last 120 years indicates the Earth is warming. The temperature data has been compared with data from other indicators including tree rings, ice cores, ocean coral and ground temperatures. Together, this data allows us to see what temperatures were like in the past. It indicates 2000-2010 was the warmest decade in modern times. The Arctic has warmed at a higher rate than the annual global average temperature.
