A version of this post appeared on CNN.com.

The shift to a clean energy economy is inevitable -- it's no longer a matter of if, but when.

Elected officials can accelerate this transition or they can impede it. We can address climate change while we still have a chance to contain it, or we can wait until the costs will be far higher and the consequences more dire.

Last week, more than 150 world leaders came to Paris to forge a global climate agreement, the largest gathering of its kind in history. All of them urged the world to take action -- and none of them denied the reality of how our world is changing.

The goal of a climate agreement is clear: to get all countries together around an ambitious and concerted long-term effort to reduce the man-made emissions that are damaging the planet. The rewards of action are vast. A strong climate agreement will send powerful signals to the market and unleash new opportunities in clean energy.

We're on the threshold of a clean energy revolution, a technological transformation that may well rival the automobile or the personal computer for its ability to change society. Over the coming years, the world will shift away from dirty fossil fuels and toward clean renewable sources of energy. The future will be defined by higher-speed, low-emissions transit, electric cars, rooftop solar panels and energy-efficient buildings.

Elected officials can make America a leader in this new clean energy future and ensure that Americans enjoy better health and a more vigorous economy, all while preserving the planet for their children and grandchildren. Indeed, many elected officials in Congress and in state and local government understand this and are already pushing ahead.

Yet some naysayers are determined to block this progress. Before heading to Paris, I testified at a hearing on Capitol Hill where some lawmakers are stuck in some backward thinking about climate change. They are arguing against American leadership and trying to undo the Clean Power Plan, the centerpiece of U.S. efforts to rein in emissions. Instead of embracing a new 21st century economy, they sow doubt about America's role in the world and its innovative spirit.

Keeping Americans Safe, Helping Businesses Thrive

In fact, it should be clear that America can and should lead on climate. At home, we must ensure that Americans are safe, our communities are protected and our businesses can thrive. But no country should act alone. Already the global climate negotiations are helping, demonstrating the benefits of U.S. leadership. More than 180 countries, representing 98 percent of global greenhouse gas emissions, have put their climate commitments on the table. Major emitters, like the European Union, China and Brazil, have set ambitious goals for limiting carbon emissions. Even smaller countries, like Ethiopia, Costa Rica and Colombia, are taking action.

The United States can also help vulnerable populations abroad where rising seas threaten to wipe away coastlines and even entire islands, and where migration patterns will likely worsen due to food shortages and droughts. This includes making sensible investments to help build the resilience of the most vulnerable countries, and reduce instability and security risks.

The U.S. has made a commitment to cut carbon pollution by at least 26 percent by 2025, through the Clean Power Plan and other measures. While some leaders question its effectiveness, the Clean Power Plan will do enormous good. It will drive innovation, slash emissions and improve public health. And it will not be costly. In fact, growing evidence finds that climate action and economic growth can -- and must -- go together.

Since 2008, U.S. wind energy has tripled and solar has increased more than 20-fold. Today, the solar industry is adding jobs nearly 20 times faster than the economy as a whole, according to the Solar Foundation. States as diverse as Texas, Iowa, Maine and Nevada are seeing their share of renewable energy surge. More opportunities are opening up with falling solar prices and fuel-efficient vehicles that save consumers money and cut emissions.

It should come as no surprise that Americans overwhelmingly support climate action. Seventy percent support placing strict limits on coal-fired power and two-thirds concur that the United States should join an international agreement to limit climate change. And many businesses agree -- more than 150 American companies recently signed a pledge in support of an international agreement.

Climate action is aligned with American values. Americans are optimistic, they find solutions, they have a can do spirit, and they don't back down when faced with great challenges. Americans believe in helping others and they certainly want a better world for future generations.

Americans want clean energy. They want clean air. They want to slow climate change and to be prepared for impacts that are already at hand. Business as usual won't cut it. Simply put, it is time for leaders to lead.