How many nukes would it take to destroy the world?

[Lorax7844]

http://www.flickr.com/photos/25541021@N00/3790865581/sizes/o/

[Buzz Clik]

1. This is assuming death coming only from the immediate explosions?

I think we have plenty to wipe out humanity.

[lunatica]

2. Or conversely, it would take one

because using one would cause the domino effect since everyone would use theirs either in retaliation or to preemptively strike against their enemies.

10 thousand nukes could destroy civilization easily, and it would take maybe two weeks at most. Nuclear winter and eventual worldwide radiation contamination would do the rest.

[donco6]

4. Oops, didn't see yours. Great minds think alike. n/t

[donco6]

3. Actually, it would only take one.

The first one.

[bananas]

5. Nuclear winter revisited

Nuclear winter revisited
Posted by: JeffMasters, 2:00 PM GMT on April 10, 2009

In the 1980s and early 1990s, a series of scientific papers published by Soviet scientists and Western scientists (including prominent scientists Dr. Carl Sagan, host of the PBS "Cosmos" TV series, and Nobel Prize winner Paul Crutzen) laid out the dire consequences on global climate of a major nuclear exchange between the U.S. and Soviet Union. The nuclear explosions would send massive clouds of dust high into the stratosphere, blocking so much sunlight that a nuclear winter would result. Global temperatures would plunge 20°C to 40°C for several months, and remain 2-6°C lower for 1-3 years. Up to 70% of the Earth's protective stratospheric ozone layer would be destroyed, allowing huge doses of ultraviolet light to reach the surface. This UV light would kill much of the marine life that forms the basis of the food chain, resulting in the collapse many fisheries and the starvation of the people and animals that depend it. The UV light would also blind huge numbers of animals, who would then wander sightlessly and starve. The cold and dust would create widespread crop failures and global famine, killing billions of people who did not die in the nuclear explosions. The "nuclear winter" papers were widely credited with helping lead to the nuclear arms reduction treaties of the 1990s, as it was clear that we risked catastrophic global climate change in the event of a full-scale nuclear war.

Even a limited nuclear exchange can cause a climate disaster

Well, it turns out that this portrayal of nuclear winter was overly optimistic, according to a series of papers published over the past few years by Brian Toon of the University of Colorado, Alan Robock of Rutgers University, and Rich Turco of UCLA. Their most recent paper, a December 2008 study titled, "Environmental Consequences of Nuclear War", concludes that "1980s predictions of nuclear winter effects were, if anything, underestimates". Furthermore, they assert that even a limited nuclear war poses a significant threat to Earth's climate. The scientists used a sophisticated atmospheric/oceanic climate model that had a good track record simulating the cooling effects of past major volcanic eruptions, such as the Philippines' Mt. Pinatubo in 1991. The scientists injected five terragrams (Tg) of soot particles into the model atmosphere over Pakistan in May of 2006. This amount of smoke, they argued, would be the likely result of the cities burned up by a limited nuclear war involving 100 Hiroshima-sized bombs in the region. India and Pakistan are thought to have 109 to 172 nuclear weapons of unknown yield.

<snip>

Nuclear winter
Lead Author: Alan Robock

<snip>

Nuclear winter is a term that describes the climatic effects of nuclear war. In the 1980's, work conducted jointly by Western and Soviet scientists showed that for a full-scale nuclear war between the United States and the Soviet Union the climatic consequences, and indirect effects of the collapse of society, would be so severe that the ensuing nuclear winter would produce famine for billions of people far from the target zones.

There are several wrong impressions that people have about nuclear winter. One is that there was a flaw in the theory and that the large climatic effects were disproven. Another is that the problem, even if it existed, has been solved by the end of the nuclear arms race. But these are both wrong. Furthermore, new nuclear states threaten global climate change even with arsenals that are much less than 1% of the current global arsenal.

What's New

Based on new work published in 2007 and 2008 by some of the pioneers of nuclear winter research who worked on the original studies, we now can say several things about this topic.

New Science:

* A minor nuclear war (such as between India and Pakistan or in the Middle East), with each country using 50 Hiroshima-sized atom bombs as airbursts on urban areas, could produce climate change unprecedented in recorded human history. This is only 0.03% of the explosive power of the current global arsenal.
* This same scenario would produce global ozone depletion, because the heating of the stratosphere would enhance the chemical reactions that destroy ozone.
* A nuclear war between the United States and Russia today could produce nuclear winter, with temperatures plunging below freezing in the summer in major agricultural regions, threatening the food supply for most of the planet.
* The climatic effects of the smoke from burning cities and industrial areas would last for several years, much longer than we previously thought. New climate model simulations, that have the capability of including the entire atmosphere and oceans, show that the smoke would be lofted by solar heating to the upper stratosphere, where it would remain for years.

<snip>

Nuclear winter

<snip>

2007 study on global nuclear war

A study published in the Journal of Geophysical Research in July 2007<8>, Nuclear winter revisited with a modern climate model and current nuclear arsenals: Still catastrophic consequences<9>, used current climate models to look at the consequences of a global nuclear war involving most or all of the world's current nuclear arsenals (which the authors described as being only about a third the size of the world's arsenals twenty years earlier). The authors used a global circulation model, ModelE from the NASA Goddard Institute for Space Studies, which they noted "has been tested extensively in global warming experiments and to examine the effects of volcanic eruptions on climate." The model was used to investigate the effects of a war involving the entire current global nuclear arsenal, projected to release about 150 Tg of smoke into the atmosphere (1 Tg is equal to 1012 grams), as well as a war involving about one third of the current nuclear arsenal, projected to release about 50 Tg of smoke. In the 150 Tg case they found that:

A global average surface cooling of –7°C to –8°C persists for years, and after a decade the cooling is still –4°C (Fig. 2). Considering that the global average cooling at the depth of the last ice age 18,000 yr ago was about –5°C, this would be a climate change unprecedented in speed and amplitude in the history of the human race. The temperature changes are largest over land ... Cooling of more than –20°C occurs over large areas of North America and of more than –30°C over much of Eurasia, including all agricultural regions.

In addition, they found that this cooling caused a weakening of the global hydrological cycle, reducing global precipitation by about 45%. As for the 50 Tg case involving 1/3 of current nuclear arsenals, they said that the simulation "produced climate responses very similar to those for the 150 Tg case, but with about half the amplitude", but that "the time scale of response is about the same." They did not discuss the implications for agriculture in depth, but noted that a 1986 study which assumed no food production for a year projected that "most of the people on the planet would run out of food and starve to death by then" and commented that their own results show that "this period of no food production needs to be extended by many years, making the impacts of nuclear winter even worse than previously thought."

<snip>

[bananas]

6. The guy who made that image is redoing it, taking into account fallout, nuclear winter, etc

He responded to the comments on his blog:
"Yup. Thanks for all the feedback. I’m going to redraft the image with radiation, fallout, nuclear winter, failure rates, poisoned water supplies, crop deaths, deformed babies, and cancer all factored in. After I’ve had this stiff drink…"

http://www.informationisbeautiful.net/2009/how-i-learnt-to-stop-worrying-and-love-the-bomb/

<snip>

12 Comments

1.
Andy Wong
Posted August 5, 2009 at 4:48 am | Permalink

You failed to account for the nuclear fallout from these bombs; that would kill many more people than the actual blast could.

Also, considering the circumstances in which nuclear weapons are used, there would be many more things besides nukes to worry about. Perhaps we’ll have massive famines and genocides all over the place.

Hitler didn’t need a single nuke to kill those 6 million+ Jews.

2.
W
Posted August 5, 2009 at 6:43 am | Permalink

True, but physical destruction is only a part of the fun of nuclear weapons. You need to calculate average fallout, mortality rates, and radiation half-life to get the full picture.

3.
Daryl Ong
Posted August 5, 2009 at 6:43 am | Permalink

How about fallout?

4.
Karthik
Posted August 5, 2009 at 8:07 am | Permalink

The problem here is that you’re looking at the blast/explosive equivalent without looking at the long term effects. If you set off 88 conventional bombs you get a huge explosion and a lot of death and destruction in the blast area, but anyone outside that zone will be fine. However, nuclear radiation is messy. It can travel in the air, gets into water supplies, doses people who were never in the blast zone. Think Chernobyl: no explosion, but people hundreds of miles away (far outside the blast zone of a nuclear weapon with larger energy release) still got cancer and gave birth to deformed babies. If you explode every bomb we have today, civilization will be over within a couple of generations, guaranteed.

So of course, why do we have so many nuclear weapons? Ability to respond and precision in targeting. We’ve got small bombs and large bombs, bombs designed to go by themselves and those designed to sit 8 to a rocket. And rockets fail too. If 20% of your nukes are ready for launch at any time (integrated on a vehicle), 50% of your launch sites are taken out, only 10% are in range of the target, and you have a 10% failure rate with your launch vehicle, then you’ve got 4 nukes at your disposal to launch. Out of 4000.

5.
William
Posted August 5, 2009 at 11:44 am | Permalink

Hold on. What about the economic and political fallout of 10% of our cities being destroyed and huge swathes of land made uninhabitable or unfarmable by fallout. I’m not so sure we could recover from that so easily regardless of how many of us survive…

6.
Ali
Posted August 5, 2009 at 9:49 pm | Permalink

10000 nuclear explosions would totally wang up our climate for several years and kill all our crops, and the fallout would kill everything else.
Only a few hundred are needed.

7.
Leif
Posted August 6, 2009 at 9:04 am | Permalink

Wouldn’t be possible to get all Nukes started: The first step in a nuclear war would be to destroy the nukes of the enemy, many are mounted on submarines oder planes and there is a (small) chance that these get shoot down or blown up before they can unleash hell :D so much for the positivie effects :D ….but nice visualisation ;)

8.
Schmul Meier
Posted August 6, 2009 at 4:27 pm | Permalink

As some of the posters before me mentioned, you didn’t take nucelar fallout into account. Have a look here:

http://www.pbs.org/wgbh/amex/bomb/sfeature/1mtfall.html

“900 Rem
Distance: 90 miles
A lethal dose of radiation. Death occurs from two to fourteen days.”

A radius of 90 miles means about 65,879 km². According to my calculation only some hundred megaton bombs are needed to kill all people on earth.

I really hope you update this blog post.

9.
david
Posted August 7, 2009 at 10:06 pm | Permalink

@Andy Yeah I guess it’ll all go a bit like The Road

10.
david
Posted August 7, 2009 at 10:16 pm | Permalink

Yup. Thanks for all the feedback. I’m going to redraft the image with radiation, fallout, nuclear winter, failure rates, poisoned water supplies, crop deaths, deformed babies, and cancer all factored in. After I’ve had this stiff drink…

11.
j.s. nelson
Posted August 8, 2009 at 12:34 am | Permalink

Also, does your figure include fire damage? That’s a huge factor often ignored in nuclear weapons damage estimation. Here’s a source:
http://www.amazon.com/Whole-World-Fire-Organizations-Devastation/dp/0801435781

Without fire damage, the figure would be extremely misleading.

12.
Cor Blimey
Posted August 10, 2009 at 12:25 pm | Permalink

this post made me re-watch Threads, the 1984 BBC docudrama.

:(

[Craftsman]

7. About 100 Megatons will cause global nuclear winter

[FarCenter]

8. There is no scaling problem with hydrogen bombs

A fusion weapon can be made as large as you want it to be. There is no limit so long as you build it and explode it in place.

Therefore, only one is needed.

Or if you want to be neater about it, you can surround a somewhat smaller weapon with materials which will produce enough cobalt 60 to kill all higher animals on earth by radiation. Cockroaches and other radiation-resistant life forms should have a nice day.

[Phoonzang]

9. You mean how many nukes would it take to wipe clean all the landmass

inhabited by humanity...