At this vital moment in the global climate crisis, corporate leadership on climate policy is a top priority.

This week, I joined ten other executives of leading nonprofit organizations in an open letter calling on corporate CEOs to use their voice, their global platforms, their credibility, and their networks to support a policy agenda to get us to net-zero emissions by 2050. That is the goal that scientists say is necessary to limit global warming and avoid unprecedented damage to our planet, our economy and our communities.

Some companies are already taking action on climate change, others not so much. Recently, 87 global companies committed to science-based targets within their global enterprises, and another 203 have committed to 100% renewables by 2050 at the latest. And many more are setting ambitious goals and meeting them.

That’s a good start. But, the one-company-by-one-company approach is not enough.

We simply can not get to a net-zero future without effective public policy at the state and federal levels—policies that will drive the market to reduce greenhouse gas emissions and scale up investments in resilient infrastructure, energy efficiency, clean energy and clean vehicle technologies.

Corporate CEOs have every reason to lead on policy and be a credible, influential voice. They have the global communications platforms to reach tens of millions of people; they have legitimate concerns about the economic impacts of climate change on their businesses and on our economy; and their consumers and employees increasingly favor companies that take action to help protect our planet.

That credibility and capital has to be spent now. We have an extraordinary challenge and we need to make extraordinary progress.

Greenhouse gas emissions are at an all-time high and continue to rise, warming the planet at a rapid rate. Scientists warn that we have to work urgently to limit average global temperature rise to no more than 1.5 degrees Celsius. It will mean cutting emissions nearly in half by 2030 and reaching net-zero by 2050.

That’s why we are calling on corporate CEOs to strongly and consistently advocate for science-based policies at every level of government. These include a price on carbon, maintaining vehicle fuel emissions standards, removing barriers to corporate renewable energy procurement, mandating corporate climate risk disclosures, fostering the electric vehicle (EV) market—and more, including innovative solutions we haven’t thought of yet.

Corporate leadership means setting climate goals, supporting climate policy, and aligning trade associations’ policy positions with a net-zero economy. The days when companies could support climate action out of their public relations office and then support the trade associations working against climate policy must end.

Institutional investors agree. Last month, 200 of them urged nearly 50 of the largest publicly traded companies to align their climate lobbying with the goals of the Paris Agreement, warning that to do otherwise would pose financial risks to their portfolios.

The good news is that some companies already have left their trade associations, while countless others are effectively working with them from within to drive change. Unilever, to cite one strong example, asks its trade associations to properly represent their vision for climate action or risk losing the company as a member. We need to see similar action from more companies.

Trust me when I say: when business leaders talk, lawmakers listen.

We know this because Ceres has been mobilizing companies around a science-based policy agenda through the Ceres BICEP Network for 10 years. Just last spring, we brought more than 75 corporate leaders to Capitol Hill to call for a price on carbon, which we believe is the most effective and efficient policy to reduce emissions while strengthening the economy and growing the job market.

Business leaders should recognize their tremendous capacity—if they don’t already—to effect positive change in the political debates on the climate crisis by consistently following a science-based approach in the policies they advocate for.

As we saw at the end of September, Greta Thunberg and other young people led more than six million people in protests around the world. They are not asking for action on climate policy—they are demanding it.

Do our corporate leaders dare ignore them?

The stakes are too high to ignore them. It’s time for our corporate leaders to speak up and take action. Their leadership is crucial to powering a net-zero economy and a just and sustainable future for all.

To the CEOs of corporate America: it’s now your turn to lead on climate policy.

Mindy Lubber is the CEO and President of Ceres, a sustainability nonprofit organization working with the most influential investors and companies to build leadership and drive solutions throughout the economy.

This article was originally posted on Forbes. Click here to view the original article.