DigitalGlobe via Getty Images

A satellite view of the Fukushima II Dai Ni Nuclear Power plant after a 9.0 magnitude earthquake and subsequent tsunami on March 13, 2011 in Naraha, Japan

At one point yesterday, as I was trying to get the latest on the Japanese nuclear crisis, I clicked over to the Wall Street Journal and the lead headline said "Officials Stabilize Damaged Complex." Immediately above that headline, in red, was a "Breaking News" alert announcing that "Another fire has broken out at the No. 4 reactor..."

Not so stabilized after all, I guess.

I don't mean to pick on the Journal. Rarely has a major international news story produced such a confusing stew of ambiguous information. Some journalists, notably Anderson Cooper on CNN, have been ramping up their criticism of the nuclear plants operator, Tokyo Electric Power, for not being forthright about what they know, but I suspect the real issue is that they don't know much at all. There is no precedent for what's happening at the Fukushima Daiichi power plant, and nobody can get close enough to thing to really see what's going on.

The confusion extends far beyond the physics of multiple "partial meltdowns." How big a health hazard is the radiation leaking from the plant? We don't really know, partly because we don't know how much is leaking but mostly because we don't know know very much in general about the health effects of radiation exposure. We hear things like, radiation levels are ten times normal, but that is not a risk. Or that someone has been exposed to a year's worth of "acceptable" radiation in an hour; does that mean they'll be just fine if they stay in a lead room for the rest for the year?

Our own reporting has revealed plenty of ambiguity. Experts we spoke to seem convinced that no matter what happens at Fukushima Daiichi, a radiation cloud blowing across the Pacific won't pose any health hazards in California. But since we don't really know exactly what level of radiation exposure might cause long-term health problems, I'm not sure I believe this. Heck, we can't even decide collectively whether radiation from cellphones or smart electricity meters is dangerous. Low-level radiation exposure won't make you sick today, but does it increase your risk for cancer 20 years from now? It depends on who you ask.

Meanwhile, we are assured that our two nuclear power plants in California are built to withstand the biggest possible earthquake that might happen at each of those locations. So San Onofre and Diablo Canyon were built to weather quakes in the 7.0 to 7.5 range. But that assumes a level of certainty in earthquake science that simply does not exist. Absolutely no chance of something greater than 7.5 at Diablo Canyon, which sits near four different faults? Really?

And what would be the consequences if the Big One hit directly in the Bay Area? We're proud of our building codes and general preparedness, but one story I read yesterday suggested that a monster quake would bring down pre-war high-rises in San Francisco (of which there are many). I guess there is preparedness, and there is preparedness.

Tsunami studies are fraught with the very same problems. On the one hand, we're told that the types of faults we have in the Bay Area don't produce big tsunamis, and they are mostly inland faults anyway. On the other hand, there are fault zones off of Washington and Alaska that are quite similar to the faults that produce the Japanese catastrophe, so maybe we could get a giant tsunami here after all.

I don't mean to be alarmist, and in fact it's part of our job as journalists in a situation like this not to be alarmist. Nobody wants to incite panic. In the midst of a huge crisis like the one facing Japan, journalists and the authorities are mostly on the same side. Everyone wants to provide helpful information, and do whatever it takes to minimize further casualties and assist those in need. In any crisis, most reporters and editors take care to avoid inflammatory or frightening language that will create more heat without shedding more light.

At the same time, the authorities are responsible for keeping people safe, and it's normal that those authorities are going to be predisposed to regard their own precautions as sufficient. And it's our job, as journalists, to investigate whether those precautions are in fact sufficient, and expose the facts, however alarming (or not) they might be. It's a tricky line to walk, for everyone.

More broadly, risk assessment is a very complicated business, and preparedness involves countless tradeoffs. Is it worth spending $100 billion today to head off a calamity that might cost many lives and $300 billion to fix tomorrow — when we don't know when, or even if, such a calamity might take place? The wise thing for an individual, moreover, might not be the wise thing as a policy matter. If my family were in Japan, I'd try to get them out, or at least urge them to get farther away from Fukushima Daiichi than Tokyo. But evacuating Tokyo is not really an option for the Japanese government.

So if you're worried, do your homework, and don't expect easy answers. At The Bay Citizen, and countless other news organizations, we're trying our best to help with the homework. Definitive answers, though, will be in maddeningly short supply.