All around the world, traditional wisdom has it that forests bring the rain. Scientists have scoffed at this notion for a while. Forests grow where there is ample precipitation, but they do not cause that precipitation. It comes because of winds that are governed by geomechanical processes, which have nothing to do with where the forests are and aren't. Water does not tend to stay in one spot for very long. Most of it ends up running off into the ocean via rivers, unless there's some way for the moisture from the ocean to come back inland, all of the lands water would be gone very quickly, as with the forest. According to the geomechanical view, moisture gets transferred inland when water vapor is carried from the ocean by winds. Because some of this water gets lost to precipitation, the deeper inland this air gets, the less moist it becomes. Therefore, deeper inland means less rainfall. If this view is true, we should expect to only see forest near the coasts and drier more erud areas the farther inland we go. But this is not what we find, where there are still natural forests, precipitation does not decrease with distance from the ocean. In fact, it often increases. The greatest amount of rainfall being in the deepest parts of the forest, sometimes thousands of miles from the coast. This is unexpected and difficult to explain with the geomechanical view. What on earth could be attracting so much water to a spot so far from the ocean? And why? While there is more water in the ocean than in forests, forested areas have more water vapor in the air. This is because forests, especially healthy ones, have a lot more surface area for water to evaporate off of. Multiple canopy layers, shrubs, moisture-laden ground are all full of water, which transpires or evaporates entering the air. As a result, we find much more water vapor in the forest, even when there is less total water. The ample amount of water vapor in the forest rises and condenses into clouds, changing from gas to liquid. This creates a drop in air pressure, which allows even more vapor-filled air to rise. This creates an upward air current, which in turn creates a horizontal current closer to the ground. This sucks in air from higher pressure areas, like the air from over the ocean. This air contains some water vapor, which increases the total amount of water in the forest, leading to more frequent rainfall. Essentially, forests create a giant constant air current that attracts moisture from hundreds of miles away. This is how we find so much water so far from the ocean. But the forests bring it in. This process is known as the biotic pump, and it shows how traditional wisdom was right all along. Forest really do bring the rain. So as more forests are clear-cut, the more extreme become the droughts and the more expensive become the deserts. If we want to thrive on this planet, we need to preserve and regenerate the forests.