Sarah,
Since your question contains multiple layers of shortages, you will need to break it down. Shortages also shift. A few places to start:
Food and Agriculture Organization of the United Nations: http://www.fao.org/home/en/
Washington Post's comprehensive section on the global food crisis: http://www.washingtonpost.com/wp-srv/world/globalfoodcrisis/
Here is a list of books in our library that could address your question: http://unomaha.worldcat.org/search?q=food+and+water+shortage&qt=results_page&dblist=638&scope=2&oldscope=2#x0%253Abook-format
CQ Researcher will also have several articles that include data charts: http://leo.lib.unomaha.edu/login?url=http://library.cqpress.com/cqresearcher Unfortunately, I can't directly link you to them, but you can enter your search term (such as global food crisis, water shortages, etc.) to pull them up.
Hope this gets you started,
Emily M., reference associate
