Water evaporates and returns to the Earth as rain. It's water from the sky.
true, but considering the worlds fresh and useable water makes up about 3-5% it really depends where you live, especially in 100 years if these is anything to go by:About the water and why:
http://www.realtruth.org/articles/435-edws.html?gclid=CI3p9tWJvosCFQ0wlAodwHHIxQ
http://www.canada.com/edmontonjournal/news/opinion/story.html?id=5fae1bbc-e8db-4edb-8a65-a0604185a9d0
In general:
http://www.bbc.co.uk/climate/
http://news.bbc.co.uk/2/hi/science/nature/6532323.stm
http://www.southbaymobilization.org/newsroom/earth.htm