1.- I think one of the most important is the Climate changes, because it's not normal how the climate changes from one day to another and this serious,. scientists are getting worry about the climate.

2.-  Another important is the Deforestation, because the tree are very important for us because they give us that is call oxygen so without them we cannot live, humans were getting down all the trees, but now I think everybody are controlling that. The reforestation is helping a lot.

3.- The Acid rain is very important too because we provoke that, this occur due to the presence of certain pollutants in the atmosphere, acid rain is a known environmental problem that can have serious affect on human health. 

I think its important to celebrate the Earth day, because we to be careful how we live and the earth is the only place we can live.......