Today, scientists have found that the greenhouse gases in the lower atmosphere have changed the global climate. These gases are largely due to human activities, such as the burning up of gas, coal and oil, and the destruction of forests. It is estimated that the average surface temperature of the earth will rise by 1.5-3.5℃ by 2100. This rate of warming is significant. The oceans will heat up and glaciers will melt. As a result, the global average sea level is expected to rise by 15-95 cm by 2100. In that case all coastal cities will be at risk as a result of flooding and storm surges. Also, around the world weather events such as storms and floods will become more frequent and intense. Clearly, global climate change is becoming a great threat to our environment. So we must take effective measures to produce fewer greenhouse gases that cause it.

　　Global climate is causes by the greenhouse gases in the lower atmosphere. These gases are largely due to the burning up of gas, coal and oil, and the destruction of forests. Scientists estimate that, by 2100, the average surface temperature of the earth will rise by 1.5-3.5℃ and global average sea level will rise by 15-95 cm. All coastal cities will be at risk as a result of flooding and storm surges. Clearly, global climate change is becoming a great threat to our environment.