Greenhouse effect is caused by industrial pollution.Because of the effect,the temperature increase .From the data taken by scientist, our earth has been warming up since the Industrial Revolution. Why does it happen? The factories' emissions have created smog in the atmosphere. The earth's atmosphere becomes like a greenhouse, and the earth and the everything inside of it have become like the plants in the greenhouse. The sunlight can pass through the ozone layer but the heat transferred by the sunlight cannot escape from the layer of smog and is deflected to earth's surface again.
