Water pumps are one common way to access underground water.
When talking about renewable and non-renewable resources, many people don't consider water. But increasing population densities, global warming and the exhaustion of some non-renewable water resources is bringing water in to the spotlight more and more. On a geological time scale, water simply moves around, but on a human time scale, shifts in the nature of water resources can have a huge impact on day to day life.
Frozen Water
One common source of renewable water is frozen water. Glaciers for instance allow for melt in the hot months while renewing themselves with snow and in some cases rainfall in the colder months. Global warming however is affecting many glaciers, causing them to melt a great deal and renew themselves very little. The question then becomes at what point are glaciers no longer a renewable resource.
Surface Water
Surface water is a water source used by billions as their primary water source. Rivers and lakes are fed by snow melt, glacial melt and rainfall, among other sources. But like many other forms of renewable water the nature of surface water is changing. Global warming is making surface water more and more scarce in places the Southwest of the United States, which puts strains on the human populations living there.
Underground Aquifers
Underground aquifers are one of the true non-renewable forms of water. Many underground aquifers are fed by rainfall, snow melt and glacial melt and are renewable, though many are being drawn down faster than their rate of renewal. But other underground aquifers are not fed by anything, they are huge water reservoirs that, much like an oil deposit, only contain so much liquid that can be drawn to the surface. When they're exhausted they will be gone forever.
Desalination
Desalination is for many people a necessity of life. Israel for instance depends heavily on desalination to maintain a steady flow of fresh water, and there are other coastal countries and cities investing in or investigating desalination as a source of water. But desalination is immensely expensive, and often indicates that a country or region has exhausted all other options.
Tags: glacial melt, Global warming, many people, melt glacial, melt glacial melt
