1) One reason why deforestation is occuring because people need wood from trees to build things, therefore, leading them to cuting countless of trees.
2) One environmental problem that results from widespread deforestation is that the carbon dioxide they would normally use remains in the atmosphere, therefore, promoting erosion.
3) One way to lessen the effects of deforestation is by re-planting the cut-down trees and by cutting down less trees.
This was my answer from the same question that you asked before
I hope it helps though :)