At present, we can see that our world have a climate variability. The more serious natural disasters such as Flood, earthquake, a severe thunderstorm. Unusually hot weather people lost their lives, including new types of epidemics. The cause of global warming because of greenhouse gases rising from the activities of man. Whether burning coal and fuel. As a result, greenhouse gases are rising to unite on the Earth's atmosphere. Make the sun's rays should be reflected back out to the right amount. These greenhouse gases to be stored. Causing global temperatures to rise gradually from the original. When the temperature rises gradually at the polar ice and the glaciers will melt quickly. Affect many living things on Earth. Such as polar bears, it will not be stepped on the ice. And the foods increasingly rare. Make the polar bear endangered species. The ice melted quickly to make water in the oceans increase many in every year. And cause the earth collapsed..