Presidential elections are about the future, creating a brighter, more hopeful tomorrow. They’re about who we are as American people, our common values and dreams. They’re about the choices we make, the directions they lead and the places we hope to go.

This year, in this election, the stakes for our future could not be higher. Our beliefs are being tested like never before. And the choice before us is crystal clear.

That’s especially true when it comes to safeguarding our environment and health from a widening array of threats to our air, water, wildlife and lands. We have it within us to reduce these risks, leave our children a livable world and do so in a way that makes us more prosperous and secure. It won’t happen, though, by itself. It’s going to take leadership.

In this moment of promise and challenge, we need a president equal to the times, someone who combines an American vision of stewardship with the judgment to find the answers to the complex web of problems before us. We need a leader we can count on to stand up to the growing dangers of climate change, create the clean energy jobs of tomorrow and protect our environment for every American.

That person is Hillary Clinton. She’s thought deeply about the environmental risks we face. She’s worked tirelessly, in the U.S. Senate and as secretary of state, to address environmental hazard and harm. And she’s laid out a comprehensive portfolio of policy proposals to take us where we need to go.

She understands that climate change is the central environmental challenge of our time, and she’s pledged real action to fight it, by investing in efficiency, so we do more with less waste, getting more clean power from the wind and sun, and modernizing our electricity transmission grid and regulatory structure to make the best use of renewable energy.

She knows we can become the clean energy superpower of the 21st century, and she’s mapped out a plan to help us get there. She sees that the shift to cleaner, smarter ways to power our future is reshaping the global economy; that it is spawning entire new industries and generating millions of good-paying middle-class jobs that can’t be outsourced or shipped overseas; that it’s the economic play of our lifetime.

And she believes that clean air and water, healthy wildlife and habitat, safe food and fertile lands are not the leftovers we scrape up after others are done, but, rather, the birthright of every American, in every community, rich or poor, and of every ethnic origin or race. That’s part of the promise we’ve made to each other, as Americans. It’s a promise we’re going to keep.

Donald Trump would turn his back on that pledge. He’s vowed to dismantle common-sense safeguards we depend on to protect our air, water, lands and food. He doesn’t believe American innovation and enterprise are up to the task of creating the clean energy economy of tomorrow; he wants instead to bet our future on the dirty fuels of the past. He calls climate change a “hoax.”

We’ll never solve a problem by ignoring it. We won’t embrace the clean energy future by locking ourselves into the dirty fuels of the past. We’ll never make America great by making America dirty again.

We need a leader who knows the difference between fantasy and fact, between standing up for the short-term profits of the few and the enduring interests of us all, between empty rhetoric that divides our people and real world solutions that unite us as one, between betting on failure and building on success.

In the eight years since Barack Obama took office, we’ve had a president who understands our obligation to protect future generations from the growing dangers of climate change, invest in the promise of clean energy and safeguard our environment for everyone. And he’s worked to strengthen protections for our wetlands and streams, set aside public lands for our future and cut smog pollution from the air we breathe.

We need a leader who will pick up this mantle, build on these gains and make good on the promise before us, not someone who will turn away from opportunity, turn back the clock on the progress we’ve made and set us on the low road back to the dirty fuels of the past and all the damage and danger they bring.

On this Election Day, our choice could not be more clear.

Donald Trump would leave our children a world more darkly at risk than it is today. Hillary Clinton would create a brighter, more hopeful tomorrow.