To some critics, there is no riskier source of electricity than nuclear power. For others, nuclear power's minimal greenhouse gas footprint makes it a vital alternative to carbon-belching coal and natural gas in the pitched battle to curb climate change -- and a far more reliable energy source, at least for now, than wind and solar power. To still others, nuclear power's advantages in the carbon war are eclipsed by the crippling economics of getting a nuclear power plant built, making it a prohibitive and wasteful investment.
Everyone is right.
At the end of last month -- just a bit shy of the two-year anniversary of the nuclear disaster at Japan's Fukushima Daiichi nuclear facility -- the World Health Organization appeared to deliver some encouraging news. Despite being hammered first by an earthquake and then by a subsequent tsunami that hobbled the plant's safety equipment and triggered the wholesale meltdown of three nuclear reactors, the impact of the released radiation on human health, the United Nations body determined, appeared to be quite low.
"The primary concern identified in this report is related to specific cancer risks linked to particular locations and demographic factors," said Dr. Maria Neira, WHO Director for Public Health and Environment, in a statement accompanying the report. "A breakdown of data, based on age, gender and proximity to the nuclear plant, does show a higher cancer risk for those located in the most contaminated parts. Outside these parts -- even in locations inside Fukushima Prefecture," she added, "no observable increases in cancer incidence are expected."
And what about those cancer risks in the "most contaminated parts?" Well, they certainly seem scary. Males exposed as infants in these areas, for example, can expect a 7 percent increase in their risk of developing leukemia, compared to the baseline risk for developing the disease in the wider population, according to the WHO report. Females exposed as infants will have a lifetime risk of developing thyroid cancer that is as much as 70 percent above baseline rates.
But as a number of folks have already noted, the key takeaway is that these percentages represent upticks over baseline risk factors that are already extremely low. From the WHO report:
Due to the low baseline rates of thyroid cancer, even a large relative increase represents a small absolute increase in risks. For example, the baseline lifetime risk of thyroid cancer for females is just three-quarters of one percent and the additional lifetime risk estimated in this assessment for a female infant exposed in the most affected location is one-half of one percent.
In other words, the report suggested, it would be difficult, in many cases, to differentiate cancers attributable to Fukushima from cancers developed in the normal course of living in a world where, well, cancers develop for all kinds of reasons -- or don't. Of course, even small upticks in cancer risk are unwelcome. But the idea that the radiation exposures associated with the worst nuclear accident since Chernobyl were comparatively modest -- Fukushima was about one-sixth as bad as the 1986 Ukrainian meltdown -- seemed to suggest that maybe nuclear power is not the nightmare many opponents believe it to be.
Obviously not everyone buys this. The environmental group Greenpeace was quick to condemn the WHO report as a whitewash, charging that the organization was hiding cancer impacts by emphasizing the small percentage upticks in risk. "Those small percentages actually translate into thousands of people being at risk," the group declared, adding that the international health organization had consulted with the pro-nuclear International Atomic Energy Agency prior to publishing its work -- a charge WHO flatly denies.
Norway's Bellona Foundation, an international environmental group, also slammed the WHO analysis, suggesting that other research being conducted on the ground in Japan, for example, had found worrying rates of thyroid abnormalities in children tested.
Last week, those dire findings were themselves undermined by further analysis that showed even higher rates of thyroid abnormalities far from the Fukushima hot zone -- suggesting that whatever was going on might have little to do with the meltdown at the Daiichi plant.
What to believe? It's hard to know. But those inclined to believe that the risks of nuclear power are overstated might still find something to fear in the grim economics of building and operating nuclear power plants compared to other sources of power. The premium was enough to prompt Jeff Immelt, the chief executive of General Electric -- no stranger to the manufacture of nuclear reactors, including those at the hobbled Daiichi facility -- to tell The Financial Times last summer that nuclear power had become "hard to justify."
"When I talk to the guys who run the oil companies they say look, they're finding more gas all the time," Immelt was quoted as saying. "It's just hard to justify nuclear, really hard. Gas is so cheap and at some point, really, economics rule. So I think some combination of gas, and either wind or solar ... that's where we see most countries around the world going."
That's certainly true in the United States, where the boom in natural gas is driving a rapid expansion of gas-fired electricity production -- which demands far less in up-front capital costs than the multiple billions needed to get a nuclear power plant off the ground. Many European countries -- most notably Germany -- have hatched plans to scale back on or wholly abandon nuclear power in the wake of the Fukushima mess.
Most construction of nuclear power, in fact, is now unfolding in Asia and other parts of the power-hungry developing world. China, which initially halted nuclear construction in the wake of the Japanese disaster, is now moving full steam ahead, with more nuclear reactors under construction than any other country on earth -- 28, according to the World Nuclear Association.
That might seem a terrifying notion to nuclear safety advocates, but given the unchecked growth of global carbon pollution and the increasingly dire threat of climate change, the comparatively smaller carbon footprint of nuclear power would seem, at the very least, a necessary evil. After all, even after China finishes building all those reactors, nuclear power will still represent less than a tenth of its electricity generating capacity -- which will continue to come, to an almost mind-boggling degree, from planet-warming coal.
In an analysis published last year, the International Energy Agency suggested that a wholesale divestment from nuclear power would be precisely the wrong move at a time when greenhouse gas emissions are increasingly out of control. Movements away from nuclear power, after all, would in large part be met with increased use of carbon-intensive sources like coal and natural gas, according to the agency's chief economist, Fatih Birol.
Germany, which has undertaken a drastic phase-out of nuclear power, has increased its coal use to compensate, and has seen its emissions begin to rise. The U.S. Energy Information Agency noted this week that in Japan, which reduced nuclear output after the Fukushima meltdown, fossil fuel use has been climbing as well.
Increasing deployment of renewable power sources like wind and solar, as well as improvements in energy efficiency, are vitally important, of course, but many of the world's experts believe that such measures are, by themselves, not enough to tackle the climate imperative facing the planet. "Renewables cannot make it alone," Birol said. "It is not enough."
Again, not everyone agrees with this notion. I'm not sure I do -- and it's likely we won't fully understand the fallout associated with the Fukushima debacle for quite some years to come. It's also true that, even if nuclear power reactors could be steeled against any and all potential catastrophes -- at a price the market would bear -- there would still be a lot of long-lived and highly toxic nuclear waste to deal with.
In that light, the best scenario would seem to call for an unassailably safe, scalable and affordable path to rapid global decarbonization that does not involve nuclear power. The only question is, how long can the world afford to keep searching for that path?
Follow Tom Zeller Jr. on Twitter: www.twitter.com/tomzellerjr