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.

As a highly tangible and personal issue, shaping everything from health and history to politics and the economy, water is an ideal lens through which to explore the key environmental issues of our time. Water is the heartbeat and gauge of climate change and health and is the one thing humans the world over agree should be protected. For many, it’s as close as the nearest tap or drinking fountain, and yet few fully understand how interconnected the water ecosystem is and how integrally our lives are linked to it.

Departing in January, Alexandra will lead "Expedition: Blue Planet" through which she will chronicle the interconnectivity of water issues during a non-stop 100-day expedition to critical water sites across five continents: from Mississippi to Cambodia, the Red Sea to Australia, and India to Botswana. A key aspect of the project will be its ability to show how individual stories are part of the larger, universal story of an interdependent, global water ecosystem. In this way, we will create a new vision for what it means to live in a world where water is our most precious resource, and a plan for what we must do to protect it.

Visit the Blue Legacy website in the coming weeks for updates on the expedition. If you are interested in participating or sponsoring the expeditions in some way, please contact info@bluelegacy.net.

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.

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!!!