Water

Aridity, rather than nitrogen supply, drives water use efficiency in global forests, new study finds

Plants greatly influence our climate. In Northern Africa around 6,000 years ago, variations in weather patterns led to decreased water availability for vast savannas, which, in turn, led to less water restored to the atmosphere through plant transpiration. Due to this negative cycle, what was once a verdant landscape became the Sahara Desert, the largest hot desert on the planet.