I agree that we need trees but at the same time we need some things and materials which made from trees. To my mind it's better not to ask the question what we need more, but to find a balance in cutting and saving trees.
I offered to find the answer on that question in order to everyone be aware off important consequences of his choice. It means before you dump one more sheet of paper in a mixed litter-bin probably you will think about trees. And you will change your mind and begin to collect a paper garbage to dump them into special bins for further recycling. So even my neighbour and I, any ordinary man can do it, do a little step to forward to saving green trees, as a consequence for saving fresh air.