When parts of Japan were devastated last month by an earthquake and subsequent tsunami, news of the human toll was quickly overshadowed by global fears of radioactive fallout from the Fukushima Daiichi nuclear power plant. The concern was understandable: Radiation is very frightening. I grew up in Denmark at a time when fear of nuclear power was pervasive.

But our latest nuclear fears have broader implications, especially for energy supply and our desire to shift away from reliance on fossil fuels. At the time of a natural disaster, it is difficult to step back and gain a broader perspective; even attempting to do so can feel crass. But there are some facts that we should not overlook.

During the round-the-clock coverage of the nuclear drama, the specter of Chernobyl has been raised repeatedly. It is worth noting that the worst nuclear disaster in history directly caused only 31 fatalities. The World Health Organization estimates that 4,000 deaths could be linked to the disaster over 70 years, whereas the OECD projects a range of 9,000 to 33,000 deaths during this period. That is substantial. But also consider that, according to the OECD, every year nearly 1 million people die from fine-particle outdoor air pollution. This massive death toll provokes no discernible fear in the developed world, and receives virtually no news coverage.

Of course, every country with nuclear power facilities should revise its safety measures in light of the Japanese disaster, which raised obvious questions about the sites chosen for such facilities. Clearly, plants located near tsunami-prone areas need to be reconsidered, and some countries have power plants in disturbingly close proximity to seismic faults—and to large cities.

But while President Obama quickly reaffirmed America’s commitment to nuclear power, some European governments took the knee-jerk decision to freeze all new nuclear-energy projects immediately, and, in the case of Germany, not to extend the life of existing reactors. For Germany, this will leave a gap that it cannot fill with alternative energy sources, leaving it little choice but to rely more heavily on coal power.

Coal is generally viewed as a polluting but reasonably “safe” energy source compared to nuclear energy. Yet, in China alone, coal-mining accidents kill more than 2,000 people each year—and coal is a leading cause of smog, acid rain, global warming, and air toxicity. As a result of Germany’s decision, its annual carbon emissions are now expected to rise by as much as 10 percent—at a time when European Union emissions are rising as the continent shakes off the effects of the financial crisis.

Germany doesn’t have a low-carbon alternative if it shutters its nuclear plants, and the same is true of most other countries. Alternative energy sources are too expensive and nowhere near reliable enough to replace fossil fuels.

Although safety concerns are paramount right now, the construction of new nuclear plants faces another hurdle: They are very expensive. New nuclear power plants have high up-front costs (which can be politically challenging), including a very complicated, slow, and fraught planning process. When completed, the total cost of nuclear power is significantly higher than the cheapest fossil-fuel source. And society must bear significant additional costs in terms of the risks of spent-fuel storage and large-scale accidents. Moreover, in most parts of the world where energy consumption is expanding, nuclear proliferation is an issue.

Then there is the question of maintaining existing plants. Decommissioning nuclear reactors may make us feel safer. But we should acknowledge that this will often mean compensating for the lost output with more reliance on coal, meaning more emissions that contribute to global warming, and more deaths, both from coal extraction and air pollution. Moreover, given that the plants are already paid for, waste facilities are already in place, and the high decommissioning cost will have to be paid regardless of timing, the actual operating costs are very low—half or lower per kilowatt-hour than the cost of the cheapest fossil fuels.

The long-term answer is more research and development—not only into next-generation, safer nuclear energy, but also into energy sources like solar and wind, which currently provide well below 1 percent of the planet’s energy. Alarmingly, this research has decreased over the last three decades.

At protests calling on politicians to respond to climate change, a cry has rung out: “No coal, no gas, no nukes, no kidding!” The harsh reality—thrown into stark relief by the Japanese disaster—is that we do not yet have the luxury of dumping coal, gas, and nuclear power. Until we can find a feasible alternative, reducing reliance on one of them means that another must take its place.

This article comes from Project Syndicate.