Cynthia Barnett is the author of Blue Revolution: Unmaking America's Water Crisis. In honor of Earth Day, we asked her "What is today's most pressing environmental issue?"  

I’m beginning to believe it’s the deep social/political/religious divides that have us too angry at one another to roll up our sleeves and work on relatively small problems, much less biggies such as climate change and freshwater scarcity.

I’ve been thinking a lot about this because I’m in the middle of writing the commencement address for Unity College. This is the wonderful environmental-themed college in Unity, Maine, where President Stephen Mulkey has elevated climate change as an ethical imperative for colleges and universities everywhere.

I’m telling the graduates: “As the global atmosphere warms, as the Arctic ice thins, as Americans sweat in the warmest spring in recorded history, our political, cultural and business leaders, and our government and private institutions, remain frozen stiff. My generation’s paralysis, which extends from the geo-political to the local, is the single-greatest barrier to solving the climate crisis...”

Part of the answer is that ethical imperative President Mulkey talks about. My latest book, Blue Revolution, is a call for a water ethic for America, in the same spirit that Aldo Leopold called for a land ethic sixty years ago. My favorite thing about the response so far is how the ethical framework transcends politics and other points of division. I am asked to speak at Vacation Bible Schools as well as universities, and make my way into the hook & bullet literature as well as the green.

This is the beauty of water. Literally a chemical bond, water is also one of the deepest bonds among people. The initial impacts of our changing climate all involve water–- changing rainfall and storm patterns, more-extreme flooding, more-severe drought. These are happenings people love to talk about, even people who don’t want to talk about climate change.

This is why I think water will be the issue around which the shouting match over climate change finally becomes a conversation. Ultimately, it will unite us.

Watch Cynthia Barnett speaking at the Clinton School at the University of Arkansas