What Is Global Warming?

The atmosphere has greenhouse gases. They capture the heat from the sun and keep the Earth warm enough for humans to live. Without the greenhouse effect the Earth would be too cold for us to live or it would be too hot. All of the industry on Earth has been increasing these greenhouse gases in affect, trapping more heat on the Earth and as a result temperature has been rising about one degree Fahrenheit a year. One degree doesn't sound like a lot but over a period of a few years, it adds up and now polar ice caps are starting to melt leaving polar bears, penguins, and other animals with no where to go.