<human>:  What is the impact of deforestation on the environment?
<bot>: Deforestation has a profound effect on the environment. It reduces biodiversity, alters ecosystem functions, affects the water cycle, increases CO2 levels in the atmosphere, and contributes to climate change. Deforestation has also been linked to a number of human health issues, including respiratory problems, lower agricultural productivity, landslides, and desertification. The loss of trees and other vegetation can also have implications for global CO2 levels and the climate.