Answer: Deforestation
Step-by-step explanation:
Rainforests have been cut down in large quantities for a variety of reasons such as lumber, farmland and population growth.
Rainforests have a lot of trees that are of very high quality and so would be very useful for furniture. Lumber companies have therefore cut large numbers of trees to make furniture.
Farmers in areas with rainforests sometime cut down trees to gain more land to use for agriculture. Sometimes they set fire to forests which consume a large area of the forest.
As the population of humans grows, there is a need for more land for humans and so rainforest trees are cut down to reclaim land from the forests. Land that is then converted to human use.