The humanitarian dimensions of nuclear weapons

Global treaties ban chemical and biological weapons, landmines and cluster munitions.

For each of these inhumane, indiscriminate weapons, the unacceptable harm they cause eventually enabled arguments about military utility to be swept aside.

Nuclear weapons, the worst of all, make these others look like child's play. Yet we have no treaty to eradicate them.

That is why this week's "Humanitarian Impact of Nuclear Weapons" international conference in Oslo is so welcome. Because sixty-eight years after the nuclear devastation of Hiroshima and Nagasaki changed our world, nine governments continue to threaten all our futures with radioactive incineration.

All the world's governments bar four agreed at the 2010 Nuclear Non-proliferation Treaty Review Conference that any use of nuclear weapons would cause catastrophic humanitarian consequences. Yet policies on nuclear weapons continue to be driven by myth. Myths that nuclear weapons can be kept but never used, that their use could be justified, that governments can be prevented from acquiring weapons others claim as essential to their security, that there can be right hands for the wrong weapons.

These myths remind me of the pre-Fukushima myths in Japan that nuclear power is essential and severe accidents cannot happen.

Evidence, not myth, needs to drive policy, especially on the most critical existential challenges. Through the Intergovernmental Panel on Climate Change, hundreds of experts worldwide rigorously review emerging evidence and present their findings to the public and policy-makers. Yet despite the World Health Organization identifying nuclear weapons as the greatest immediate threat to human health and welfare, we have no such process for nuclear weapons.

In fact the most acute climate threat we face is nuclear. Atmospheric scientists confirm that just one hundred Hiroshima-size nuclear weapons (small by today's standards) detonated on cities would ignite coalescing fires, injecting more than five million tons of smoke into the stratosphere. Abrupt global cooling, darkening, and reduced rainfall, persisting for over ten years, would deplete food production. One billion people already chronically malnourished would starve. Loss of food imports, conflict and infectious disease epidemics would jeopardise hundreds of millions more.

Nuclear famine could be triggered by less than 0.5 per cent of the world's current stockpile of nuclear weapons and less than 0.1 per cent of their total explosive power. Thus, the arsenals of China, France, India, Israel, Pakistan and UK, not only of Russia and the US, pose existential global threats. Nuclear weapons anywhere are our common enemy.

The first five states to acquire nuclear weapons (the "P5" – China, France, Russia, UK and USA) are jointly boycotting the Oslo conference. According to Rose Gottemoeller, US Acting Under Secretary for Arms Control and International Security, the US decision was taken in consultation with the other P5 states. The US administration views the Oslo conference as a distraction; diverting attention, discussion and energy away from the practical step-by-step approach which they feel is most effective to stabilise and reduce nuclear dangers. Although the P5 regard others of their club as potential nuclear adversaries, when nuclear weapons are challenged, it seems a united front is possible.

For the states which between them own more than 98 per cent of the world's nuclear weapons to collectively boycott the conference is reprehensible. It indicates an unwillingness to face the facts about the horrifying catastrophe any use of nuclear weapons would unleash, the impossibility of any effective humanitarian response, and the resultant urgent need to eradicate the scourge of nuclear weapons. It suggests dysfunctional denial in being unwilling to review updated evidence about the greatest immediate threat to human health and welfare. It ignores the need for evidence to drive policy, especially on such critical matters. Unfortunately, ignoring the threat will not make it go away, it only increases it.

The P5 boycott is doubly misguided as the outcome document of the 2010 Review Conference of the nuclear Non-Proliferation Treaty (NPT) for the first time recognised the catastrophic humanitarian consequences of any use of nuclear weapons. This document was supported by all 189 states signed up to the NPT, including the P5. The P5 repeatedly emphasise the importance of the NPT.