We are living in strange times. German Chancellor Angela Merkel, a conservative politician and until a few months ago, a longtime supporter of nuclear power, has vowed to shutter her nation's 17 nuclear reactors and make renewable power, such as wind and solar, Germany's dominant source of energy by 2030. Meanwhile, staunch British environmentalist George Monbiot, the popular Guardian columnist and a former nuclear foe, has recently argued in a series of forceful columns that the nuclear risks are overstated and that ramping up nuclear power is the only way to meet the world's rising energy needs and also reduce carbon emissions. Let me acknowledge that they are not equal players. Merkel is a head of a state, who has the power to make government policy. Monbiot is a pundit, who has the power to influence public debate. Still, I feel like I've entered a Bizarro World, where some of the characters, like in that hilarious Seinfeld episode, have come face to face with their opposites. How did we get here? Well, Merkel's and Monbiot's respective transformations were each set in motion by the recent tsunami in Japan and the resulting disaster at the Fukushima Daiichi complex, which still has not been resolved. They have viewed the accident through very different lenses, however. To Monbiot, an "old plant with inadequate safety features was hit by a monster earthquake and a vast tsunami." And yet, for everything that's gone wrong, "as far as we know, no one has yet received a lethal dose of radiation," he wrote in March. In that column, he concluded:

Atomic energy has just been subjected to one of the harshest of possible tests, and the impact on people and the planet has been small. The crisis at Fukushima has converted me to the cause of nuclear power.

Merkel's reaction was just the opposite, and it is startling, given that, as Christian Schwägerl recounts in this Yale E360 article, "Only last year, she [Merkel] fought to extend the operation time of Germany's reactors by 12 years on average, against fierce opposition from the left and environmental groups." In his piece, Schwägerl tries to deciper Merkel's about-face on nuclear power:

In my view, the key to the chancellor's radical turnaround lies deep in her past. In the 1980s, well before she became a politician, Merkel worked in the former East Germany as a researcher in quantum chemistry, examining the probability of events in the subatomic domain. Her years of research instilled in her the conviction that she has a very good sense of how likely events are, not only in physics but also in politics. Opponents of nuclear energy were "bad at assessing risks," she told me in the 1990s. Then came the March disaster at the Fukushima-Daiichi nuclear power plant, which made the chancellor realize that she had been terribly wrong about the probability of a nuclear catastrophe in a highly advanced nation. Merkel's scientific sense of probability and rationality was shaken to the core. If this was possible, she reasoned, something similar might happen in Germany "” not a tsunami, of course, but something equally unexpected. In her view, the field trial of nuclear energy had failed. As a self-described rationalist, she felt compelled to act. "It's over," she told one of her advisers immediately after watching on TV as the roof of a Fukushima reactor blew off. "Fukushima has forever changed the way we define risk in Germany."

Meanwhile, back in England, Monbiot had launched himself on a fact-finding mission to reassess the risks of nuclear power. He came to a completely different conclusion than Merkel. In a column last month, Monbiot says he "made a deeply troubling discovery":

The anti-nuclear movement to which I once belonged has misled the world about the impacts of radiation on human health. The claims we have made are ungrounded in science, unsupportable when challenged, and wildly wrong. We have done other people, and ourselves, a terrible disservice.

Monbiot's sudden embrace of nuclear power is largely driven by his concern over climate change. His is not the first high profile conversion. In recent years, Stewart Brand, an icon of the environmental movement and the founder of Whole Earth Catalog, has famously become a big booster of nuclear power. Climate change has also made a believer out of NASA climate scientist James Hansen. While I wouldn't put him in the same boosterish category as Brand, Hansen is not shy about talking up the need for nuclear power. In his recent book, Storms of My Grandchildren, Hansen writes that, "it seems clear that efficiency and renewable energies will not be sufficient to allow phaseout of coal." Like Monbiot, Hansen doesn't believe that clean tech is ready for primetime--at least not at the global level. But it's also not ready to power England's energy needs, according to a group of advisors to the UK government, known as the Committee on Climate Change (CCC). Earlier this week, the group issued a report that said the fastest way to a low-carbon future for England would be to include nuclear power. It projects that by 2030, about 40 percent of the UK's energy needs could be met by nuclear, and 40 percent by renewables. As CCC's chief executive David Kennedy told BBC News, "nuclear at the moment looks like the lowest cost low-carbon option." In contrast, Germany's Merkel has put forward a plan that takes nuclear power out of the picture altogether. As Schwäger writes in his article:

The numbers that circulate in Berlin's government district at the moment are staggering. Merkel's administration plans to shut down the nuclear reactors "” which in recent years reliably provided up to a quarter of Germany's huge needs as baseload electricity "” by 2022 at the latest. It wants to double the share of renewable energy to 35 percent of consumption in 2020, 50 percent in 2030, 65 percent in 2040, and more than 80 percent in 2050. At the same time, the chancellor vows to cut CO2 emissions (compared to 1990 levels) by 40 percent in 2020, by 55 percent in 2030, and by more than 80 percent in 2050.

Is this realistic? "The new course is a huge challenge in terms of cost and feasibility," Schwäger concludes. He does the math and finds that "three quarters of Germany's electricity sources will have to be replaced by green technology within just a few decades, if the nuclear phase-out and the CO2 goals are to be accomplished." It seems to me that Merkel, in removing nuclear power from the energy equation, is perhaps making her ambitious plan more challenging and less doable than it need be. The no nukes strategy also isn't necessarily a path that some experts believe should be emulated on a global level. As MIT's John Deutchsaid in 2009:

Taking nuclear power off the table as a viable alternative will prevent the global community from achieving long-term gains in the control of carbon dioxide emissions.

In yesterday's Financial Times, Ted Nordhaus and Michael Shellenberger of The Breakthrough Institute echo Deutch:

Put simply, there is no credible path to stabilising, much less reducing, global carbon emissions without more nuclear power. We are a planet of 6bn people, heading toward 9bn. Even with better energy efficiency, global energy demand will soon double, perhaps triple. Without nuclear power, the vast majority of that demand will be met by fossil energy.

If there is a middle ground "” one that includes nuclear and renewables, then it appears that Japan is vowing to stake it out. Despite the catastrophes it's been hit with, Japan has signaled that it isn't about to stop using nuclear power. But at the same time, Japan's prime minister has just announced that renewables and conservation will become two new pillars of Japanese energy policy. Time will tell which of these countries "” England, Germany, or Japan "” have charted the quickest path to a low carbon future that can meet all their energy needs.