A recognised cause of drought and, finally, desertification, is the clearance of trees and bushes from the land. Trees and bushes retain water, reduce the impact of heavy rain on the soil, and keep the areas under and around their leafy branches cooler than the surrounding cleared areas.
The trees release the water as vapour into the atmosphere, creating rain. Removal of this cover leads to erosion and flooding.
We are seeing this pattern emerging in New Zealand.
Trees and hedges have been cleared to create more pasture. We are seeing the results now, with an increased number of droughts and severe flooding in the winter.
Interested people can check trees for water retention right now. Even trees in isolated positions have a ring of green vegetation around them. Look for the animals. They are crowded under the shade and cooler atmosphere of the trees. You do not need a doctorate in science for some things that are common sense.