The Fourth National Climate Assessment made headlines in recent weeks for sounding alarm bells about current and future effects of climate change. It’s a strong reminder to consider the most effective solutions. Environmental organizations have long advocated for climate change solutions. But last summer, I learned that some of these organizations may not be doing the most they can do. While tabling at an event for the environmental non-profit I was interning with, I encountered a peculiar young man. He had stopped by our table to learn about the organization’s priorities and the action items available for passersby to take. He pulled out his pen, seemingly happy to fill out a postcard urging Massachusetts legislators to strengthen a renewable energy policy. But after asking a clarifying question on the policy at hand, he put his pen back in his pocket, and walked away.

Why? The policy targeted on the postcard, Massachusetts’s renewable portfolio standard, omitted nuclear energy. I asked myself: isn’t nuclear energy unsafe? Or too expensive? And what about the risk for nuclear proliferation? Anti-nuclear energy sentiments are well-known; nuclear energy has a bad reputation. Yet, this man was disgruntled to learn that RPS policy excludes nuclear energy. I sought an explanation. Ultimately, this interaction fueled a curiosity in me, and caused me to start thinking differently about energy solutions designed to address climate change.

Under the old RPS law, electricity providers in Massachusetts were required to derive 13 percent of their electricity in 2018 from renewable sources such as wind and solar. That percentage was to increase by one percent annually. But, many environmentalists argued that that growth was not enough to meet the mandatory carbon emissions goals outlined in Massachusetts’s 2008 Global Warming Solutions Act (GWSA). The postcards were asking legislators to support a 2 or 3 percent yearly increase to achieve reductions of 80 percent below statewide 1990 greenhouse gas emissions by 2050—the GWSA goal. Ultimately, the state legislature increased the percentage to two percent in July of 2018. It was a seeming victory in the fight against climate change.

Well, not quite. Nuclear energy remained off the list of eligible sources of electricity, and that’s a real loss for Massachusetts. Because of one person who refused to sign an RPS postcard, I did my research. What I learned convinced me that nuclear energy can work wonders for a carbon-constrained world. I also learned that there is an important distinction between clean and renewable energy. Clean simply indicates that the energy source produces very low levels of carbon dioxide and other greenhouse gases that contribute to climate change. Renewable energies are therefore also considered to be clean energies. But not all kinds of clean energy are renewable. Although nuclear energy is a clean energy, because it does not produce direct carbon emissions, it isn’t considered renewable because there are finite amounts of uranium deposits (the fuel for nuclear power) on earth.

Massachusetts, along with the 29 other states (plus Washington, D.C.) that have adopted RPS programs, need to move away from the narrow focus on renewables. More attention should be paid to the promises of nuclear energy because renewables are not enough to substantially reduce carbon emissions alone. A recent MIT study concludes that a clean and dispatchable energy source is necessary if we want to achieve meaningful reductions in greenhouse gas emissions on time. Renewable energy isn’t dispatchable (it is not readily available whenever it is needed) but importantly, nuclear energy is. If clean energy portfolio standards were adopted and nuclear energy embraced in electricity portfolios, then utilities would have more of an incentive to look at nuclear energy as a way to adhere to the law and as a way to reduce carbon emissions. Under current RPS programs, nuclear energy innovation is stifled and the promises of nuclear fly under the radar.

Including nuclear energy in energy portfolio standards could also help halt the trend of shuttering U.S. nuclear power plants. Massachusetts’s own Pilgrim nuclear power plant is set to close by June of next year. With this closure, Massachusetts will lose more low-carbon energy in one day than all low-carbon energy that was added by the solar and wind energy industries in the past 20 years. That’s not something to take lightly.

As for concerns about safety, cost, and nuclear proliferation, we can set those aside. What few people realize is that nuclear power has a better safety record compared to other sources of electricity. The newest generation of nuclear reactors are designed with the best safety and security measures. And, innovations in construction and design are likely to make nuclear less costly in the future.

Renewables alone cannot solve climate change. It’s a dangerous myth. In light of recent climate change studies, we need to consider all options. Right now, we aren’t considering all the possibilities—specifically, we aren’t considering nuclear energy. Before we can, we need to change our attitudes on nuclear. A good first step in achieving this would be adding nuclear energy in with the renewables that are already widely accepted by the public.