paper is a kind of tool & inventing a tool allows / enables that tool to be used ->  inventing paper allows paper to be used  inventing paper allows paper to be used & if something is allowed to be used then the use of that something might increase ->  inventing paper might increase the use of paper  using paper requires creating paper & creating paper requires cutting down trees ->  using paper requires cutting down trees  using paper requires cutting down trees & if something requires something else then increasing that something requires an increase in that something else ->  an increased use of paper requires an increase in the number of trees cut down  cutting down trees has a negative impact on an ecosystem / organisms living in an ecosystem & if something has a negative impact on something else then increasing the amount of that something has a negative impact on that something else ->  increasing the number of trees cut down has a negative impact on the environment  an increased use of paper requires an increase in the number of trees cut down & increasing the number of trees cut down has a negative impact on the environment ->  an increased use of paper has a negative effect on the environment by increasing the number of trees cut down  inventing paper might increase the use of paper & an increased use of paper has a negative effect on the environment by increasing the number of trees cut down ->  the invention and increased use of paper has a negative impact on the environment by increasing the number of trees cut down  the invention and increased use of paper has a negative impact on the environment by increasing the number of trees cut down & an impact means an effect -> a negative effect of the invention and use of paper is an increased number of trees cut down