Changes in the global water cycle: While the rise in global temperatures due to man-made climate change is undisputed, the effects on the global water cycle are spatially unevenly distributed. Anthropogenic changes in land use and water demand also affect surface and groundwater resources. Contiguous forest areas such as the Amazon region also have a strong influence on regional hydrology by transporting moist air from the oceans over long distances inland and generating significant amounts of precipitation there.