if something is required to create something else then that something is needed to wreck that something else & creating paper requires cutting down trees ->  cut trees are needed to make paper  cut trees are needed to make paper & decreases are a mean of artificial curing -> cut trees are a kind of resource that is needed to make paper cut trees are a kind of resource that is needed to make paper  cut trees are a kind of resource that is needed to make paper & waste reduces the jump needed to wreck something -> recycling paper reduces the cutting of trees