what best describes the water cycle?

Answer 1

The water cycle is usually broken into 4 basic steps:
1) evaporation / transpiration / sublimation
2) atmospheric storage
3) condensation / precipitation
4) runoff/infiltration / surface storage

There is as much water on the planet today as there was when dinosaurs roamed the Earth. There will always be plenty of water.

Now, if we are talking about useful water, we need to reexamine this. You may first want to look at NASA's global water map:
http://www-surf.larc.nasa.gov/surf/pages/water.html

NASA also has a page for global water distribution:
http://earthobservatory.nasa.gov/Library/Water/
This page illustrates the tiny portion of useful water on our planet.

There are two larger issues that NASA does not discuss in their global water distribution. 1) Keeping in mind that the US has just about the same amount of water available as it did 200 years ago, there are now 250 million to share with instead of the 4 million of 200 years ago. 2) Of the roughly 3/4% of fresh water in groundwater and lakes and streams around the world, much of that is too polluted to drink.

With regard to the coming urgency for "Thinking Globally - Acting Locally", check out Jonathan Harris' "infographics" poster:
http://www.princeton.edu/~ina/infographics/water.html When our neighboring countries run out, they will be forced to do what you do when you run out of sugar in the middle of a recipe - run over to the neighbor's for some.

When we waste water, we are not only using our drinkable water but we are also moving water to the undrinkable part of the water distribution. True, we aren't losing any water on this planet, but we are losing useful water and won't be getting any more new water, either.

If we do, it will be in the form of a large icy comet and we probably won't need water at all after that.

Answer 2

The earth has a limited amount of water. That water keeps going around and around and around and around and (well, you get the idea) in what we call the "Water Cycle".
This cycle is made up of a few main parts:

evaporation (and transpiration)
condensation
precipitation
collection

Answer 3

Evaporation and condensation.