Schoolwork is mainly distributed through the following mediums: worksheets, textbooks, exercise books and tests. Among these we can observe that the majority of these use paper. Around the world, schools have traditionally relied on these materials to teach students in classrooms.
Here is an estimation of the scale of paper usage in schools alone: “Let's say that in a school of 100 teachers, each teacher gets a 50-ream allotment. Each ream holds 500 sheets, so per teacher, that would be 25,000 pieces of paper. In a class of 30 students that is 833 pieces of paper per student per year. This would mean at a school of 100 teachers, that school would use 250,000 piece of paper annually.” 
Paper consumption is very high in the education industry, and printing textbooks take up quite a percentage of that each year. The issue of regularly producing new editions of textbooks (and rendering older ones useless) is also worrying as it then creates paper waste. If we switch to tablets, however, all of these problems would be resolved, as one electronic textbook uses no paper at all.
[P1] Printing textbooks results in a high consumption of paper.
[P2] High consumption of paper means an increased deforestation rate.
[P3] Increased deforestation rate worsens the issue of global warming.
[P4] Global warming is detrimental to the environment.