America has a historic opportunity to lead the world in an energy transformation, create millions of clean energy jobs, and protect itself from dangerous dependence on foreign oil, all while protecting the planet from the most dangerous impacts of global warming pollution. The American Clean Energy and Security Act (ACES), passed last June by the U.S. House of Representatives, will put us on a path of innovation and economic growth. That's the conclusion of some of the world's top economists, including two Nobel prize-winners (click here, here, and here--see page 10).

Yet whenever these opportunities are near, the debate invariably focuses on one thing and one thing only:

What will it cost?

What will it cost, what will it cost, what will it cost?

Economic study after economic study gets released. Millions of dollars get spent on consultants. A dizzying array of numbers splatter the newspapers and airwaves. And regardless of who funds them, they all conclude the same thing: economic growth allows household incomes to grow many times more than the estimated costs of protecting the planet (click here for an industry example, and here for studies by the Energy Information Administration at the Department of Energy, the Environmental Protection Agency and the Congressional Budget Office). It would seem like a no-brainer.

Unfortunately, the economic consensus showing climate legislation is more than affordable doesn't seem to be enough. Critics are demanding estimates of the benefits, measured in dollars.

This is quite a daunting task, since some of the most important benefits of climate protection cannot be expressed in such crude terms. How do we put a price tag on lives lost to extreme weather events, on the lives of our children and grandchildren, on preventing species extinction and losses of entire ecosystems, on destruction of our beautiful coral reefs, on the disappearance of our majestic alpine habitats and other national treasures, to name only a few? We can't.

But fortunately, we don't have to. Measuring only the smidgen of benefits from climate protection that can actually be monetized (e.g. protecting crops from temperature increases, and coastal properties from rising sea levels), the Institute for Policy Integrity at New York University's School of Law took the bold step of adding these benefits up and comparing them to the (much smaller) cost of transforming our energy system. Using the most conservative assumptions at every corner, their study finds that this limited subset of benefits could be as much as 9 times higher than the costs. The authors drew upon damage estimates that have been thoroughly vetted: first, the estimates were peer-reviewed by experts in the field, and second, by a U.S. interagency task force. While the task force considers its estimates preliminary, the Department of Energy feels confident enough in the task force's review process to begin using them in rulemakings.

And it bears repeating: the benefits they measured are only a very small subset of possible climate impacts--those that can be readily expressed in monetary units. They exclude the things we value the most, such as human life, nature, and the well being of future generations.

When considering how small the costs of climate protection are, and how vast the benefits are compared to these costs, history will judge us very harshly if we do nothing. The time to act is now. The opposition has run out of excuses: the moral imperative, the science, and the economics all point to bold and aggressive action. All we need now is the political will.