Leading article: Fukushima has revealed the dangers of the nuclear road

The world has still not really come to terms with the scale of what has happened in Japan – let alone what will prove to be the global consequences of the earthquake, tsunami and nuclear crisis. It has been shocking to see one of the wealthiest nations reduced to such devastated impotence. The Japanese government is overwhelmed by the scale of damage and the enormous demand for food and water. The affected area has even been forced to appeal for coffins because it cannot cope with the number of cremations required. Amid the ruins the pitiful cry "please help us" has been heard repeatedly from a people previously associated with stoic inscrutability.

There have been inspiring moments – such as the discovery of a man alive after five days under the rubble – but they have been precious few. Most moving has been the courage of the handful of workers braving explosions and fires in the three crippled Fukushima nuclear plants in an attempt to contain the risks. The 50 men have put their lives on the line, working frantically as the plants collapse around them, knowing that they and their anti-radiation suits are all that stand between the world and the second-worst nuclear accident in history.

The implications of all this for the rest of us remain unclear. Global commodity and currency markets have been plunged into uncertainty. The impact will be felt on jobs, not least in Britain, which has a number of big Japanese-owned factories. The price of gas for next winter has already risen to a three-year high. But the greatest consequences are likely to be in the nuclear power industry.

In recent years the imperatives of climate change and energy security brought a rethink on nuclear power, which had fallen out of favour internationally after the disastrous accident at Chernobyl in 1986, which sent a plume of radioactivity from Ukraine right across Europe, as far as Ireland. Nuclear plants produce electricity without the global-warming emissions produced by power stations which burn fossil fuels. They also offered independence from oil or gas controlled by repressive middle-eastern regimes. More than 400 nuclear reactors are now being built or are planned around the world.

Fukushima has prompted a re-examination of those plants in Germany, China and elsewhere. Britain must now do the same. We may not live in an earthquake zone on a geological fault line, but plants such as Sellafield are on the coast. We need to know more about the risk of sea-rise, flooding and other potential hazards. This crisis highlights the problems inherent in nuclear power, where reactors cannot be shut down as simply as coal- or gas-fired plants. The earthquake caused the turbines and reactors to close down, as they are designed to do in a seismic emergency. But fuel rods need to be constantly cooled. Fukushima had pumps to do that, but the earthquake knocked out their power supply. There were back-up diesel generators, but the tsunami rendered them ineffective. The need for some deeper thinking on standard safety procedures is now clear – as is the necessity for governments and the nuclear industry to be open with the public about the risks and benefits involved.

We need to end our reliance on fossil fuels if we are to avoid runaway global warming. And the current unrest in the Middle East demonstrates the perils of importing energy from unstable and undemocratic regimes. Nuclear seemed to offer a way forward. Yet Japan's disaster illustrates the significant dangers that lie down that road. And of course, there is no entirely satisfactory answer to the question of how to dispose of radioactive waste. Fukushima shows us that there is no simple solution to the world's energy crisis. The debate about how we can safely and ethically power our economies must continue.