Climate change is a long-term change in the average weather patterns that have come to define Earth's local, regional and global climates .Climate change differs to climate variability as climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. Some noticeable effects of climate change that are occurring today increased such as human emissions of heat-trapping greenhouse gases are already having widespread effects on the environment and heat waves, glaciers and ice sheets are shrinking, river and lake ice is breaking up , plant and animal geographic ranges are shifting and much more