Vital to all life on Earth, water moves through our world in a constant state of flux. Cycling endlessly through ecosystems, flowing under the poles and through the atmosphere, changing states, laying waste to entire regions or achieving perfection in the shape of a single snowflake - water is a mystery and a miracle, a source of conflict and a cause for celebration, a blessing and, in its absence, a curse.

Alexandra Cousteau created Blue Legacy with the goal of telling the story of our water planet to the world, inspiring people to take action on critical water issues in meaningful ways and helping to shape society’s dialogue to include water as one of the defining issues of our century and the primary vehicle through which climate change will be felt.

Read more about the programs of Blue Legacy.

It appears that the scale and seriousness of climate change is at last being grasped. In 2008, we stand on the brink of a historic consensus, not only between scientists, but in the corridors of political power and in boardrooms across the globe.

Principal Voices is stimulating discussion on the major challenges facing the world today. As in previous years, Principal Voices is bringing together some of the world's leading thinkers in their respective fields to discuss Climate Change. Read more on CNN.com.

Please tune in to CNNI to watch this important documentary at the following times:

We all use water throughout our day... but how much is too much? The H2O Conserve Water Calculator is designed to help you measure how much water you use, better understand the ways you use water in your daily life, and get you thinking about what you can do to use less.

Calculating your "water footprint" gives you an estimate of the total amount of water you use in your home as well as the water that is used to produce the food you eat and the products you buy. Your water footprint also includes other factors such as the water used to cool the power plants that provide your electricity, and the water that is saved when you recycle. You may not drink, feel, or see this water, but it makes up the large majority of your water footprint.

It is important to understand that the H2O Calculator relies on national averages and approximations, and since not everyone's lifestyle is "average", your results should be considered an estimate of your water use and not a scientifically accurate assessment.

START CALCULATING YOUR WATER USAGE!!!