That means human activities such as burning the fossil fuel and deforestation due to an increase the carbon dioxide into the air. Then carbon dioxide and nitrogen mixtures are hurtful to our environment accumulating in the atmosphere.  But the ozone layer in the atmosphere is getting thinner and thinner. Ozone layer in the atmosphere helps to reduce the intensity of ultra-violet light penetrating into the earth.  So the Earth rises the average temperature every decade. Also, if the global warming is increasing gradually, it may cause many serious problems in the Earth. For example, the are the two poles will be less and less. The habitat for those animals living there is decreasing. The sea level will rise and may cause tsunami.

      'Green house effect' is an environment problem. Meaning is the atmosphere can reflex the particles and control the Earth temperature rises. But recently, the green house effect is not load well. It is because the humans want them to have more places. So they are illegal deforestation in the African. You know that forest help the Earth to absorb the carbon dioxide and release the oxygen. Also the Amazonian animals may be disappearing if the illegal deforestation is continuing.

Therefore I think the effective step toward solving the problems would be compromise among nation. This is a very difficult, but it is a only way. Further suggestion safe the Earth.