Carol Collier, friend, colleague, soon-to-be (tomorrow!) AWRA President and Executive Director extraordinaire of the Delaware River Basin Commission, also finds time to advise students in Penn's Master of Environmental Studies program. She sent me this video produced by her MES student Jeffrey Cowan.
In general I liked the video; good production values. The focus on ecosystem services and natural capital is very good and something you don't generally see in a water video.
Okay - some comments:
1) Cowan is off by a factor of 1000 in his estimate of the total water on Earth: it is 1,386,000,000 cubic kilometers (see G. Hornberger et al., 1999, Elements of Physical Hydrology, p. 9). The number he gives as all water on Earth is actually the 1/10 of 1% he cites as the water available to humans - 1,386,000 cubic kilometers, which is a lot of water.
2) The low relative amount of water ascribed to sustainable groundwater needs to be checked. One could argue that all groundwater that is 'sustainable' shows up as baseflow to streams, and in the USA at least, that figure is pegged at about 40-50% of streamflow for small- and medium-sized streams. Here is an interesting paper addressing this issue; see also USGS Circular 1186 by W. Alley et al.
3) He makes a number of blanket statements such as that every one of us will be affected by water problems, we won't be able to find the water for increased food and energy production, etc. I would question these statements. How does he or anyone know this?
It's nice to see students doing projects like this instead of some dry tome that will get placed on a shelf or in an electronic folder, never to be seen again.
Just check the facts.
Have a great 2013!
"We never know the worth of water till the well is dry." - Thomas Fuller, 1732