See https://www.youtube.com/watch?v=CZExWtXAZ7M and this: "In the letter, which is addressed to “those influencing environmental policy but opposed to nuclear power,” the quartet argue that renewables “like wind and solar and biomass will certainly play roles in a future energy economy,” but that such renewables “cannot scale up fast enough to deliver cheap and reliable power at the scale the global economy requires.” [James] Hansen is one of the world’s leading climate experts, renowned for warning Congress about global warming in 1988 when he worked at NASA. Under the George W. Bush administration, he bravely battled efforts to muzzle federal scientists. And in April he announced that he was leaving NASA to be a full-time climate activist. Hansen was joined in signing the letter by Ken Caldeira of the Carnegie Institution, Kerry Emanuel of the Massachusetts Institute of Technology, and Tom Wigley of the National Center for Atmospheric Research. From the letter:

Global demand for energy is growing rapidly and must continue to grow to provide the needs of developing economies. At the same time, the need to sharply reduce greenhouse gas emissions is becoming ever clearer. We can only increase energy supply while simultaneously reducing greenhouse gas emissions if new power plants turn away from using the atmosphere as a waste dump. …

We understand that today’s nuclear plants are far from perfect. Fortunately, passive safety systems and other advances can make new plants much safer. And modern nuclear technology can reduce proliferation risks and solve the waste disposal problem by burning current waste and using fuel more efficiently. Innovation and economies of scale can make new power plants even cheaper than existing plants. Regardless of these advantages, nuclear needs to be encouraged based on its societal benefits. …

With the planet warming and carbon dioxide emissions rising faster than ever, we cannot afford to turn away from any technology that has the potential to displace a large fraction of our carbon emissions. Much has changed since the 1970s. The time has come for a fresh approach to nuclear power in the 21st century." https://grist.org/climate-energy/more-nukes-james-hansen-leads-call-for-safer-nuclear-power-to-save-climate/