In the past, the current There is a subtle, natural destruction is one of the reasons that cause pollution and cause stems from a cut tree and forest destruction continues, it is likely that more will be added in the future.
In the recent past The destruction of nature, which is one of the reasons that cause pollution. And the reason is due to the cutting of trees and deforestation is likely to continue increasing in the future.
At present, the past. The destruction of nature, which causing pollution. And the causes that caused by the tree cutting forest destruction and still tend to increase in the future.