I have been asked this (or similar questions) many times and it just shows that most people do not understand what is really happening. The woods used for  manufacture of cellulose are one of the best managed natural resources on our planet.  As years go by, the pine woods used for pulp are not only continuing to exist, but are actually growing! The reason is that woods used for pulp are good  business and as such, people involved in their administration make sure that their business will continue to be profitable in the long run.  Thousands of people make their living by making an intelligent use of these natural resources, the same way as most farmers take good care of their land. Opposing the use of pulp is as silly as being against agricultural farming.