Let’s hope President Trump doesn’t treat the nuclear button as impulsively as he fires off tweets.

The mushroom cloud of one of the French military’s nuclear weapon tests above the atoll of Mururoa in 1971. Galerie Bilderwelt/Getty Images

As of 2017 there are 14,900 nuclear warheads – and most of them belong to either the US (6,800) or Russia (7,000). The UK has 215, China 260, North Korea, 10 and a few other countries hold a handful of nuclear bombs.

The US has the B83 – a nuclear bomb which generates 1.2 megatons of TNT – the equivalent of 79 Hiroshima atomic bombs.

With Trump’s recent and terrifying comments about boosting the US nuclear arsenal and not ruling out using any of these weapons in the Middle East or Europe, we felt it best to work out – for your horror – what would happen in the event of a nuclear apocalypse. What would happen if every nuclear weapon in the world today was fired and detonated? In short, nothing good.

Here’s the rather grim mathematics and science behind the end of the world.

Say one of these B83s went off in Moscow, because President Trump lost a Twitter war with President Putin and everything escalated rather quickly. If it detonated at the surface, it would leave a crater 420 meters (1,378 feet) across and 92 meters (300 feet) deep, according to NukeMap by nuclear historian Alex Wellerstein.

Almost instantly upon detonation, a gigantic fireball would appear, 5.7 square kilometers (2.2 square miles) in size and reaching temperatures up to 83.3 million degrees Celsius (150 million degrees Fahrenheit).

A nuclear weapon detonation – test Baker – conducted by the US military just offshore Bikini Island. US Army

In order to get a very rough explosive yield for all the world’s nukes, we’ll only include the US and Russia’s, but assume they are each as powerful as the B83. That’s 13,800 thermonuclear bombs, altogether producing about as much energy as the entire US does in an entire year.

Each of these devices will hit land and detonate at the surface. Assuming they’re evenly spaced out across the world’s cities and towns, and maybe a village or two, this will annihilate 94 kilometers (23 cubic miles) of land immediately – but that’s nothing compared to what happens next.

232,000 square kilometers (90,000 square miles) of infrastructure will be blown away by the air blast. That’s about 295 metropolises the size of New York City turned to dust.

A fireball 79,000 square kilometers (31,000 square miles) will vaporize literally anything it touches, and anyone within a 5.8 million square kilometer (2.2 million square miles) area would get third-degree burns. So everyone in the same space as 3,700 cities the size of London would be scorched.

Lastly, the fallout and ionizing radiation would contaminate an area of the world about 284,000 square kilometers (110,000 square miles) in size and give most of the initial survivors radiation sickness. Of course, a lot of this fallout would reach the lower atmosphere and spread across the world, so casualties would be far higher in the long term.

So at the very least, hundreds of millions, perhaps billions, will die within the first hour. This is awful enough as it is, but what happens next?

Nuclear winter

Finally, if there are any survivors who haven’t succumbed to radiation poisoning, they will have to prepare for darkness.

Similar to the concept of volcanic cooling – where particulate matter from large-scale volcanic eruptions get into the upper atmosphere and cool the overall temperature of the planet – a nuclear winter would cool the world for hundreds of years.

The black carbon soot produced from the monumental explosions would block solar radiation reaching the Earth’s surface, plunging the world into darkness, rendering photosynthesis impossible, and bringing about the collapse of the ecosystem.

Suffice to say, this would all but stop photosynthesis. Only the hardiest of plants would not die out, which would lead to a collapse in the global food chains. There would be a mass extinction event – including perhaps our own species – and the survivors would have to fend for themselves in an irradiated landscape.

So yeah, not great. Let’s hope President Trump doesn’t treat the nuclear button as impulsively as he fires off tweets.

Source: “What Would Happen If Every Single Nuke In The World Went Off At The Same Time?” originally published by IFLSCIENCE!