The short-term human and economic costs of the Japanese earthquake and tsunami are staggering.

The long-term repercussions could be worse.

That's because, even if the situation does not deteriorate any further, the fires, explosions, radiation leaks at the Fukushima Daiichi nuclear plant will  lead to greater scrutiny -- and higher costs -- for new nuclear plants.

That will make it harder to develop low carbon energy to replace fossil fuels and avert potentially catastrophic climate change.

I say this although I believe we should try to avoid a rush to judgment.

It's hard to know what's worse: the opportunism of anti-nuclear activists like Ed Markey, the Massachusetts congressman who only hours after the troubles began declared that

what is happening in Japan right now shows that a severe accident at a nuclear power plant can happen here

or the no-need-to-panic defense of industry backers like William Tucker who wrote in the Wall Street Journal on Monday that

If a meltdown does occur in Japan, it will be a disaster for the Tokyo Electric Power Company but not for the general public.

Oh really?

What I hope to do here is provide a little context -- about the costs of  nuclear power and the alternatives.

Let's begin with the alternatives. Thanks to the website oilprice.com, here are a few widgets that show where our energy is coming from, around the world and here in the U.S.:

While I understand that we can't project a future based on past trends, what jumps out at me from these charts is how thoroughly the global and U.S. energy markets are dominated by fossil fuels. Note that the numbers for solar, wind and geothermal are expressed in mBTU. You have to lop off the last three digits to compare them to the figures for oil, coal, natural gas and nuclear.

Given today's low natural gas prices, and the abundant supply of coal in the U.S. and China, which are the world's two biggest energy consumers, as you'll see below, and the absence of a price on carbon, there's little doubt that a pullback from nuclear will mean more burning of fossil fuels.

The costs of nuclear plants, meanwhile, are already steep and bound to get steeper. Just last month, the Union of Concerned Scientists published a sobering 146-page report called Nuclear Power: Still Not Viable Without Subsidies. [PDF, download]

"Since its inception more than 50 years ago, the nuclear power industry has benefited—and continues to benefit—from a vast array of preferential government subsidies," writes Doug Koplow, a Harvard MBA who has written about natural-resource subsidies for years. Virtually every segment of the nuclear business, from the mining of uranium to the construction of power plants to the under-pricing of cooling water, gets favorable government treatment, the report says.

The most important subsidies are not cash, but policies that shift construction and operating risks from the plant owners to taxpayers.  The report says:

Reactor owners, therefore, have never been economically responsible for the full costs and risks of their operations. Instead, the public faces the prospect of severe losses in the event of any number of potential adverse scenarios, while private investors reap the rewards if nuclear plants are economically successful. For all practical purposes, nuclear power's economic gains are privatized,  while its risks are socialized.

That sounds terribly familiar, doesn't it?

Particularly relevant in the context of Japan is the Price-Anderson Act, which limits total industry liability in the event of an accident.

You can be sure that the debate about the safety of existing and proposed U.S. plants, which is already underway -- see, for example, Can U.S. Nuclear Plants Handle a Major Natural Disaster at ProPublica -- will either increase the regulatory costs of developing new plants or impose more redundant (in a good sense) safety measures as part of plant construction, or both.

Today, Kevin Book, the top-notch energy analyst with ClearView Energy Partners, wrote today [PDF, download] :

Fear factor. Yesterday, German Chancellor Angela Merkel suspended electricity production at seven nuclear plants built before 1980, pending a three-month review.... The political response goes well beyond Germany. On Monday, Switzerland froze construction of three already-approved new plants. Austria's environment minister and the U.K. energy secretary have initiated their own safety investigations. Although U.S. reactions may not be as dramatic, prospective construction faced headwinds from the high absolute costs of nuclear plants and high relative costs vis-à-vis other conventional sources, and we would not be surprised to see lukewarm Congressional nukes supporters cooling to them fast.

None of this is good news for anyone who worries about global warming. Over the past few years, as I've spoken to a range of people -- Stewart Brand, David Keith and Ken Caldeira, among others -- I've grown more concerned about the climate crisis and more inclined to support nuclear power as a low-carbon solution, particularly given that all forms of energy production create risks and require tradeoffs.

But the nuclear options looks a whole lot less attractive today than it did a week ago. And that's a problem.