01/16/2014 02:27 pm ET Updated Mar 18, 2014

Eyes on the Prize

I've written a lot about the consequences of relying on fossil fuels for energy, but the chemical spill into West Virginia's Elk River still comes as a shock. Almost a week later, thousands are still without drinking water, and many of those who've been given the "all clear" have been hospitalized shortly after drinking or bathing in water they were told is clean. And yet this disaster is just a single, impossible-to-ignore, example of the constant toll that fossil fuels exact upon us every day.

If you're like me, each new disaster leaves you angry and frustrated. That's normal. But here's the one thing we can't afford to forget:

It doesn't have to be this way.

Humanity has been given a wonderful gift: We know how to get all of the energy we need without using dirty or dangerous fuel sources. It's no longer a question of whether we can -- but of whether we will.

The amount of accessible energy from the sun and wind is far greater than what the entire world is projected to need in coming decades. The key word there is accessible. We already know how to reap that energy bounty -- worldwide -- with technology that already exists (and will only get even better).

This isn't speculation. Scientists and engineers have crunched the numbers and shown that it's doable: a 100 percent clean-energy economy.

Mark Z. Jacobson and Mark A. Delucchi, professors at Stanford and U.C. Davis, respectively, published an article in Scientific American five years ago that showed how the world could be powered by clean energy within decades. Last year, they published an even more detailed plan, in Energy Journal, for how the state of New York could switch to 100 percent clean energy by 2050. They've since produced draft plans for California and Washington, as well.

Read these plans, and you'll know right away that they aren't fanciful. Resources, technology, and economics are all taken into account: We can do this. Exactly how hard -- or easy -- will it be? My hunch is that it will be challenging but perhaps easier than most people think -- but the important point is that this should be our goal. If we know we can achieve 100 percent clean energy, why would we settle for less? Even if we set aside their many drawbacks, is there a single good reason to rely on coal, oil, or natural gas if we don't have to?

Every week, I read about new clean energy successes, whether it's yet another utility deciding to add more renewable generation (because it's the cheapest option), an innovative plan for financing community solar, or the news that the new Popemobile is an electric bicycle. Yesterday it was the news that both Spain and Denmark got more power from wind than any other source last year. I can't get enough of these stories. But I also know that each of them is only one more step toward the ultimate goal: 100 percent clean energy.

That's why every time I hear President Obama or someone in his administration talk about an "all of the above" energy policy, it's like fingernails on a solar panel. If someone asked you which way leads to the top of a mountain, would you tell them "all of the above"? Of course not. The route to the summit might not be direct or easy. But if you ever want to get there, you need to know which way is up and which way is down.

We all know the adage about the forest and the trees. People in general aren't always good at seeing the big picture or taking the long view. Politicians are usually worse than most. Leaders, though -- true leaders -- have the ability to show us the mountaintop and inspire us upward.

That's the kind of leadership we need to see from President Obama, and he can start by making it official that 100 percent clean energy is our goal.