[nickserv]

Citation needed.

Also, even if true, a lot is likely due to people leaving the countryside and migrating to the cities during the latter half of the 20th century. To feed these urban populations, an enormous amount of food needs to be imported from other countries. So really the deforestation has been exported, same as pollution from manufacturing.

[tokai]

You don't need citation for common knowledge.

[nickserv]

If OP had said "in last 40 years" then yeah sure.

But since the middle ages, or 500 years ago, how is that common knowledge?