Facing Planetary Enemy No. 1: Agriculture

Consider: Cropland and pasture now cover 40 percent of our planet’s land surface; farming consumes nearly three-quarters of all the water that humans use for any purpose; farming accounts for a third of all the emissions of greenhouse gases that humans release into the environment. (Those greenhouse emission come from clearing forests or grassland for crops, the emissions of methane from rice paddies, and the conversion of nitrogen fertilizer into nitrous oxide — a powerful greenhouse gas.)
The NPR Report