As of Sunday, April 16, Germany is no longer producing any electricity from nuclear power plants.

Closures of the Emsland, Isar II, and Neckarwestheim II nuclear plants in Germany were expected. The country announced plans to phase out nuclear power in 2011. In the fall of 2022, with the Ukraine war constraining access to energy especially in Europe, Germany decided to keep these existing nuclear reactors operating for an additional few months to bolster supplies.

“This was a highly anticipated action. The German government extended the lifetimes of these plants for a few months, but never planned beyond that,” David Victor, a professor of innovation and public policy at UC San Diego, told CNBC.

Responses to the closures ranged from aghast that Germany would shut down a clean source of energy production while global response to anthropogenic climate change continues to be insufficient, to celebratory that the country will avoid any nuclear accidents like those that have happened in other parts of the world.

A collection of esteemed scientists, including two Nobel laureates and professors from the likes of MIT and Columbia, made a last-minute plea in an open letter published on April 14 on the nuclear advocacy group’s website, RePlaneteers, to keep the reactors operating.

“In view of the threat that climate change poses to life on our planet and the obvious energy crisis in which Germany and Europe find themselves due to the unavailability of Russian natural gas, we call on you to continue operating the last remaining German nuclear power plants,” the letter states.

The Emsland, Isar II and Neckarwestheim II facilities provided more than 10 million German households with electricity, the open letter states. That’s a quarter of the population.

“This is hugely disappointing, when a secure low carbon 24/7 source of energy such as nuclear was available and could have continued operation for another 40 years,” Henry Preston, spokesperson for the World Nuclear Association, told CNBC. “Germany’s nuclear industry has been world class. All three of those reactors shut down at the weekend performed extremely well.”

Despite the shutdown, some segments of nuclear industrial processes will continue to operate. “Germany’s nuclear sector will continue to be first class in the wider nuclear supply chain in areas such as fuel fabrication and decommissioning,” Preston told CNBC.

While the open letter did not succeed in keeping the nuclear reactors open, it does underscore a crucial reason why nuclear power has been part of global energy conversations recently, after a generational lull in the construction of nuclear power plants: climate change.

Generating electricity with nuclear reactors does not create any greenhouse gases. And as global climate change response efforts continue to fall short of emission targets, nuclear energy is getting renewed consideration.

“Obviously many people in the nuclear industry are disappointed that the government that cares a lot about climate change is shutting massive sources of zero-carbon electric power,” Victor told CNBC.

That view was echoed by Hans von Storch, a climate researcher at the Institute for Coastal Research in Geesthacht, Germany, and a signatory of the open letter, told CNBC.

“While a legitimate decision, it is not a wise decision,” Storch told CNBC. “This out-phasing of nuclear, with existing plants,  leads to an increase of greenhouse gas emissions in Germany, even though according to another political decision, the fast decarbonization should have priority.”

“For me, as a climate scientist, the whole thing is incomprehensible,” Storch told CNBC.

“The nuclear phase-out makes Germany safer and avoids additional high-level radioactive waste. The risks of nuclear power are ultimately unmanageable. No insurance in the world covers the potentially catastrophic extent of damage from a nuclear accident,” a spokesperson for the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection in Germany told CNBC.

On June 30, 2011, “the nuclear phase-out law was passed with a broad, nonpartisan majority,” the spokesperson told CNBC.

Volker Quaschning, a professor of renewable energy at the Hochschule für Technik und Wirtschaft Berlin, supports Germany closing its nuclear reactors because of the risk of an accident.

“Nuclear energy is a risky technology. During the Chernobyl reactor accident, Germany was hit by radioactive fallout. A reactor accident in Germany would make large parts of the country uninhabitable. In the course of global uncertainties, the risks for nuclear energy are also increasing,” Quaschning told CNBC.

Also, radioactive waste management is “still unsolved in Germany,” Quaschning told CNBC. “No one in Germany wants a repository for highly radioactive waste near them.”

Instead, the European country says it is focused on building out its wind and solar energy production. By 2030, Germany aims to generate 80 percent of its electricity from renewable energy sources like wind and solar. “We are now putting the policies in place for this and adapting the necessary legislation,” the German government spokesperson told CNBC.

Turning off the nuclear reactors opens the doors for renewables to be the future of energy, Niklas Höhne, a professor the mitigation of greenhouse gases at Wageningen University in the Netherlands, told CNBC.

“In the German context, the phase-out of nuclear energy is good for the climate in the long term. It provides investment certainty for renewable energy; renewables will be much faster, cheaper and safer than expansion of nuclear energy,” Höhne told CNBC.

Nuclear energy is also often more expensive than wind and solar power, Quaschning said, adding, “there are no longer any real advantages with nuclear energy.”

“Nuclear power plants are a hindrance to the energy transition. They are not able to run in stop-and-go mode and cannot really compensate for power fluctuations that arise when using solar and wind energy. With Germany looking to expand solar and wind power very rapidly over the next few years, now is a good time to shut down nuclear reactors to make way for renewable energy,” he said.