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Scientists stress the effects of a nuclear attack

A comprehensive briefing updated in June, forwarded by the author of Three Generations Left

The BBC reports today that after President Donald Trump warned North Korea it should be “very, very nervous” if it does anything to the US, Defence Secretary James Mattis warned that armed conflict with North Korea would be “catastrophic” and said diplomacy was bearing fruit. “The American effort is diplomatically led, it has diplomatic traction, it is gaining diplomatic results,” he said.

Edited extracts:

At a series of intergovernmental conferences starting in 2013, extensive evidence was presented of the enormous ‘humanitarian consequences’ should nuclear weapons ever be used again in war.

One study published by the organisation Article 36 was a detailed analysis of the impacts of a single modern nuclear warhead exploding over a typical city within an industrialised nation. The target was Manchester in the UK as a model medium-sized modern city. The yield of the warhead was 100,000 tonnes (100kT) – similar to many of the smaller warheads deployed by the US, Russia, France and UK.

The immediate impacts of blast from the explosion were estimated using the city’s night-time population. Very conservative casualty estimates were around 210,000 people injured – many very seriously – and around 80,000 killed immediately by blast. Many of those injured would likely die from their injuries. These figures do not take account of injuries due to flash burns arising from the fireball, severe fires or longer term health impacts. Similar casualty figures were found for a warhead exploding at ground level. This would slightly reduce the radius of blast and fire damage but instead would create a long lethal zone of radiation capable of killing and injuring people many miles downwind.

These results are based on widely accepted casualty models and are therefore reasonable minimum estimates of the impacts.  A range of humanitarian organisations (including UN agencies and the Red Cross) have concluded that the detonation of just one such weapon near any centre of population anywhere in the world would overwhelm the health infrastructure, making an effective humanitarian response impossible. 

Larger warheads and multiple warhead missiles

One 800kT warhead dropped on a city like Manchester would mean an estimated 240,000 killed and 535,000 injured. On top of this, one would expect large numbers of deaths and injuries due to flash burns, severe fires and conflagrations or even a firestorm. One RS-20 missile with ten such warheads could destroy ten urban areas with total deaths of at least 2.4 million and injuries of at least 5.4 million.

It should also be remembered that these casualty figures would only apply to the (very numerous) medium-sized cities. Nuclear warheads would be much more devastating if targeted on larger cities, such as Shanghai (population: 24m), Moscow (12m), London (8.5m) or New York (8.5m). For example, Moscow would suffer an estimated 760,000 immediate deaths with 2.7m injured from one US Trident Mk-5 warhead. For Shanghai, estimated fatalities are 3m with 4.4m injured.

This devastation would not be the end of the story. The next section looks at the longer-term effects of a nuclear war, in particular, disruption to the global climate, the ozone layer, ecosystems and food supplies.  

Exploding nuclear warheads over ‘combustible targets’ such as cities and factories would lead to widespread, intense fires that would inject massive amounts of smoke into the atmosphere leading to the formation of extensive high-altitude smoke clouds. These would cause cooling of the climate in a similar fashion to that observed after very large volcanic eruptions (for example, Krakatoa in 1883), but on a rather larger scale, threatening agriculture and hence food supplies across the world. Other effects included major damage to the ozone layer – which protects humans and ecosystems from damaging ultra-violet rays from the Sun – and the long-lived effects of radioactivity.

The use of greater numbers of larger Russian and US nuclear warheads would cause even higher levels of cooling and greater climate impacts lasting a decade or more. The 1,800 US and Russian warhead scenario would cause a long-lasting cold period with a peak global cooling of 4°C, whilst the full scale nuclear war would cause 8°C. Frosts, drought and monsoon disruption would severely impact crop production for several years.

Finally, levels of nitrogen oxide gas and soot particles created by the nuclear explosions would severely damage the Earth’s protective ozone layer. It has been estimated that 50% of the protective value would be lost. This would increase the levels of ground level ultra-violet radiation and skin cancers amongst any survivors. It would also severely affect waterborne life by damaging phytoplankton which are a key part of the oceanic and freshwater ecosystems and provide a vital food supply for all larger aquatic creatures.

The destruction of vital infrastructure such as health care, water, food and energy supply systems, and a complete disruption of communications and trade, the longer-term consequences for the Earth’s environment would present very severe challenges for all those who survived the initial detonations. Realistically, after a large scale nuclear war, one should imagine a brutalised, traumatised shattered society violently thrown back into a pre-industrial age. Assuming that humanity at large could survive this global catastrophe, any ‘recovery’ would surely be measured in hundreds of years. Even after what has formerly been considered a small scale nuclear war, the consequences would still be dire across the globe, far beyond the conflict zones.

It has to be regarded a shocking indictment of our ‘civilisation’ that current stockpiles of nuclear weapons are sufficient to cause such a global catastrophe.  

The fully referenced report may be read here: