All eyes will be on New York City this week, as world leaders come together for the United Nations Climate Summit—an event that aspires to shape the national and global energy future.

The U.N. Climate Summit will build global partnerships among representatives from business, science, advocacy and government sectors. These partnerships will take action on an essential plan to reduce carbon pollution and address global climate change. This plan must include realistic actions that take us toward sustainable energy solutions, including building renewables and harnessing the strengths of nuclear energy, which provides 60 percent of clean carbon-free energy in the U.S. today.

It’s critical that the U.N. act now. An alarming U.N. report released last week showed that in 2012, carbon dioxide emissions increased significantly—more than twice the average increase in carbon levels in recent decades. At the U.N. summit, President Barack Obama will meet with other world leaders to discuss ways to lower emissions of carbon, methane and other gases contributing to global climate change.

To do this, leaders around the world are developing initiatives to reduce pollutants from fossil fuels, doubling energy efficiencies, doubling renewable energy’s share in the global energy mix and building access to modern energy services. Like any parent, I want to leave the Earth better off for my children, with a solid mix of energy sources that provide a stable life, not only for them, but also for their children. However, the reality is that as of yet, renewables like solar and wind can’t deliver the amount of electricity and heat needed to power our cities. Because of this, reliable nuclear energy remains a vital source of power that can meet increasing demands without carbon pollution.

There’s no question among the U.N. leaders that we should be moving toward renewables. Some of the plans on the table this week include a renewable energy corridor uniting Eastern and Southern Africa and a framework to move the developing countries toward a greater use of renewables.

However, it’s only common sense to continue to invest in a healthy, diverse mix of all electricity sources. This will provide a solid foundation for economic development in developing countries while protecting our planet. While discussions at the U.N. this week will focus on moving toward sustainable energy solutions, they should also take into account power sources that we know can deliver 24-hour, always-on power cleanly, like nuclear energy.

The summit will attempt to build a consensus globally on long-term solutions, none of which will be easy. The real work will begin when local leaders go home and begin taking action. As mayor of Dallas, I faced the same concerns these leaders face every day: balancing the power needs of millions of residents with meeting state and federal emissions reduction goals. It’s a job that’s made so much easier when you know you have a reliable, safe source of baseload electricity, such as Indian Point Energy Center outside New York City.

Indian Point powers 2 million homes and supplies 25 percent of the big city’s bright lights. A recent study conducted for the city of New York found that if Indian Point were shut down, carbon pollution would increase by 15 percent in both New York City and New York state.

The global community is at a crossroads when it comes to addressing climate change. International studies have also shown that if we can’t slow our progression toward increased temperatures, the world will soon feel the impact through rising sea levels, which will damage the health and economy of coastal cities such as New York City.

I appreciate the work our global leaders will be doing this week to lead us toward a working international agreement for the good of our economy and environment, and I’d urge them to remember that maintaining an investment in nuclear energy is the only way to keep the lights on, while keeping people healthy and safe from the projected environmental and climate impacts of global warming. While we work toward meeting climate change goals, carbon levels are rising too quickly to disregard one of the best tools in our belt. Nuclear energy must remain a significant part of the mix here at home and around the world.

Ron Kirk is a co-chair of the Clean and Safe Energy Coalition. He is a former U.S. trade ambassador under President Barack Obama and a former mayor of the city of Dallas. The Clean and Safe Energy Coalition is a national grassroots coalition funded by the Nuclear Energy Institute that promotes the economic and environmental benefits of nuclear energy as part of a green energy portfolio.