Drained wetlands that humans dug up for farming contain lots of carbon leaking into the atmosphere, which traps more heat. If the air is 1°C warmer, a little bit more water will evaporate than the ground gets back from rainfall each year. Once groundwater reserves reach zero, you have drought, starvation, less roots binding soil, and then just an unfertile desert like Mars. To let nature be alone, we must undo our damages so that nature can do it's job. Trees won't grow if we asphalt everything over.