Give examples of how humans have increased their food supply and what effects these methods have on the environment overall.

Answer 1

Here are a few ideas. You should research the effects yourself.
(1) irrigation
(2) improved-yield plant types using selection, hybridization and genetic modification
(3) use of fertilizer
(4) crop rotation
(5) use of pesticides
(5) larger farms and agribusiness-owned farms
(6) mechanization