Deforestation involves cutting down trees to clear land for farming, mining, roads, and grazing cattle. This increases atmospheric CO2 levels and contributes to global warming. The effects of deforestation include desertification, climatic changes, flooding, insect plagues, impacts to agriculture, and fuel use as trees no longer absorb carbon dioxide and produce oxygen. Deforestation has also negatively impacted populations, caused extinction and loss of biodiversity, and historically contributed to events like the Dust Bowl in the United States.