Hiroshima reconsidered

My mother was neither scientific nor political, not a hoarder either, but this newspaper lay in her drawer until she died in 2016. Evidently the news of the nuclear bombs left a deep impression. She was not alone. The news dramatically changed society's perception of the world of science. Should our children and grandchildren inherit this view, or should they re-examine the story with a scientific eye to the future of the world that they themselves face today?

The inhuman consequences of war do not hang on any particular technology. The levelling of Syria since 2011, the destruction of Dresden, Tokyo, Berlin and Hamburg in World War Two – these used the blast and fire of conventional bombs. The nuclear bombs of 1945 killed similar numbers by blast and fire, yet their political impact was greater and persists today.

What happened that August day in 1945 commanded instant awe. It was seemingly way above everyone's educational pay grade, but being impressed is not a step towards understanding. An essential part of natural science became sealed off in the public mind and labelled "to be feared and avoided", as if unnatural and intrinsically malign. It was not the first time in human history that the forces of nature had been deployed and demonised for military and political purposes. But mankind makes advances by exorcising apparent demons in nature, in nuclear energy as in fire or thunder and lightning.

During the Cold War the threat of a global nuclear holocaust haunted the public imagination. To the possible destruction of many cities was added the ghoulish horror of radiation, thought to cause widespread cancer and, worse, genetic abnormalities inheritable by later generations. These sincerely held beliefs were cloaked in apparent scientific respectability. Born in a period of espionage, secrets and fake news, this horror story sustained its own excitement, undeterred by all evidence to the contrary. Today any global threat from nuclear weapons depends on this public fear of radiation and those concerned to perpetuate it for ideological reasons.

For some three billion years life has survived moderate levels of environmental nuclear radiation, from rocks, from space, from within living cells themselves. If it had not learnt how to overcome this, we should not be here. Unlike a virus radiation does not change. Once biology had established a protective strategy – a combination of replacement, cellular design, active response and an ability to adapt – moderate doses of radiation no longer threatened.

The medical health of more than 86,000 survivors of Hiroshima and Nagasaki and their descendents has been followed ever since and compared to others not exposed. No evidence for excess genetic abnormalities has been found, and for half a century the records show less than twelve excess annual deaths from cancer. Many other studies confirm that the evolved protection works well despite the large energy disparity between radiation and the weak molecules of life. Less than fifty deaths from radiation at Chernobyl, and none at all at Fukushima, tell a similar story. But the most unequivocal accounts of the effects of radiation concern people and animals who are not predisposed to fear it. For example, quite large radiation exposures occur in diagnostic scans and even greater ones in cancer therapy. These have successfully prolonged lives since the work of Marie Curie a century ago.

Nevertheless, society genuinely needs drama and excitement, and enjoys Star Wars, murder mysteries and dramatized disasters, whether true or not. But in the real world how does nuclear compare to the global threats of the coronavirus and climate change?

A virus is contagious and can multiply rapidly by infection, but radioactive contamination cannot. Sadly, the public is not told that radiation is not contagious, and at Fukushima evacuees from the contaminated region were shunned. Although nuclear energy is not a physical global threat, fear of nuclear has gone viral and become an endemic social condition. If the world is to reach zero carbon, this "virus" has to be suppressed. We have the "vaccine", a short dose of basic science, but administering it effectively is challenging.

Before the Industrial Revolution mankind's needs were provided by the power of sun, wind and water, courtesy of the seasons and intermittent weather. The population remained small, and life was short and miserable. The arrival of the reliable and concentrated energy from fossil fuels enabled a vast leap in living standards. For two centuries world affairs were a question of who had access to these fuels, and who did not.

But no longer. The accelerating process of climate change is evidently already advanced and irreversible. But at least we should mitigate it by forgoing the use of carbon fuels within twenty or thirty years, as now seems widely accepted.

But reverting to weather-driven "renewables" is not a viable option, in theory or in practice. They are so weak that, to harvest enough energy, huge areas are appropriated at the expense of nature – flooded river valleys, solar and wind plants. Their description as "farms" camouflages the extent of their destructive impact. But more significantly, their output fluctuates randomly, with capacity between 22% and 37% in the case of wind. The only future for the fossil fuel industry is short term, covering for the unreliability of "renewables". This is witnessed by the enthusiastic advertisements of oil and gas interests in support of "renewables". But following fossil fuels cannot lead to zero carbon, obviously.

The traditional view of Hiroshima throws a negative light on the wholescale international adoption of nuclear energy. And the self interest of the powerful fossil fuel industry and the misguided idealism of many environmentalists agree. Yet nuclear fuel has a million times the energy density, a 24/7 availability, a safety record second to none and a negligible environmental footprint. The science is beyond doubt; only the "virus" of radiophobia obstructs the public image. We should ensure that our grandchildren appreciate the real message of Hiroshima for today, the opportunity to mitigate climate change using nuclear energy worldwide. Those nations that invest in nuclear know how and public understanding in the next twenty years will be masters of the next industrial revolution, provided that their technical choices are based on sound natural science.