The World After Nuclear War Carl Sagan
Date: December 23, 2016 04:26AM
The Nuclear Winter: cc
Carl Sagan, a modern-day Renaissance man of science, was horn in 1934 in New York. After graduating with both
a B.A. and a B.S. degree from the University of Chicago, Sagan completed his M.S. in physics and earned a Ph.D. in
astronomy and astro-physics in 1960.
Sagan was nominated to join the Smithsonian Astrophysical Observatory in 1962. At the same time, he also
worked with the Nobel-prize winner Joshna Lederberg, investigating the origins of life on earth, and taught
genetics at Stanford. Sagan then taught astronomy at Harvard until 1968, when he became profossor of
astronomy and space sciences at Cornell University. He was then appointed director of the laboratoy for Planetary
Studies. Sagan was awarded the NASA medal for exceptional scientific achievement in 1972, after his hypotheses
about Mars were validated by data obtained from the 1971 Mars Mariner expedition. Beginning in 1968, Sagan
was editor of Icarus, the international journal of astronomy, and wrote many distinguished books. His works
include The Cosmic Connection (1973), which received the Campbell Award for best science book; the Pulitzer-
prize winning Dragons of Eden (1977); Broca's Brain (1979), on developments in neurophysiology; and Cosmos
(1980), which accompanied his widety-acclaimed television series. In "The Nuclear Winter" (1983), Sagan explored
the unforeseen and devastating physical and chemical effects of even a small-scale nuclear war on the earth's
biosphere and life on earth.
Except for fools and madmen, everyone knows that nuclear war would he an unprecedented
human catastrophe. A more or less typical strategic warhead has a yield of 2 megatons, the
explosive equivalent of 2 million tons of TNT. But 2 million tons of TNT is about the same as all
the bombs exploded in World War II -- a single bomb with the explosive power of the entire
Second World War but compressed into a few seconds of time and an area 30 or 40 miles
In a 2-megaton explosion over a fairly large city, buildings would be vaporized, people
reduced to atoms and shadows, outlying structures blown down like matchsticks and raging
fires ignited. And if the bomb were exploded on the ground, an enormous crater, like those
that can be seen through a telescope on the surface of the Moon, would be all that remained
where midtown once had been. There are now more than 50,000 nuclear weapons, more than
13,000 megatons of yield, deployed in the arsenals of the United States and the Soviet Union
-- enough to obliterate a million Hiroshimas.
But there are fewer than 3000 cities on the Earth with populations of 100,000 or more. You
cannot find anything like a million Hiroshimas to obliterate. Prime military and industrial
targets that are far from cities are comparatively rare. Thus, there are vastly more nuclear
weapons than are needed for any plausible deterrence of a potential adversary.
Nobody knows, of course, how many megatons would be exploded in a real nuclear war.
There are some who think that a nuclear war can be "contained," bottled up before it runs
away to involve much of the world's arsenals. But a number of detailed analyses, war games
run by the U.S. Department of Defense, and official Soviet pronouncements all indicate that
this containment may be too much to hope for: Once the bombs begin exploding,
communications failures, disorganization, fear, the necessity of making in minutes decisions
affecting the fates of millions, and the immense psychological burden of knowing that your
own loved ones may already have been destroyed are likely to result in a nuclear paroxysm.
Many investigations, including a number of studies for the U.S. government, envision the
explosion of 5,000 to 10,000 megatons -- the detonation of tens of thousands of nuclear
weapons that now sit quietly, inconspicuously, in missile silos, submarines and long-range
bombers, faithful servants awaiting orders.
The World Health Organization, in a recent detailed study chaired by Sune K. Bergstrom (the
1982 Nobel laureate in physiology and medicine), concludes that 1.1 billion people would be
killed outright in such a nuclear war, mainly in the United States, the Soviet Union, Europe,
China and Japan. An additional 1.1 billion people would suffer serious injufles and radiation
sickness, for which medical help would be unavailable. It thus seems possible that more than 2
billion people-almost half of all the humans on Earth-would be destroyed in the immediate
aftermath of a global thermonuclear war. This would represent by far the greatest disaster in
the history of the human species and, with no other adverse effects, would probably be
enough to reduce at least the Northern Hemisphere to a state of prolonged agony and
barbarism. Unfortunately, the real situation would be much worse. In technical studies of the
consequences of nuclear weapons explosions, there has been a dangerous tendency to
underestimate the results. This is partly due to a tradition of conservatism which generally
works well in science but which is of more dubious applicability when the lives of billions of
people are at stake. In the Bravo test of March 1, 1954, a 15-megaton thermonuclear bomb
was exploded on Bikini Atoll. It had about double the yield expected, and there was an
unanticipated last-minute shift in the wind direction. As a result, deadly radioactive fallout
came down on Rongelap in the Marshall Islands, more than 200 kilometers away. Most all the
children on Rongelap subsequently developed thyroid nodules and lesions, and other long-
term medical problems, due to the radioactive fallout.
Likewise, in 1973, it was discovered that high-yield airbursts will chemically burn the nitrogen
in the upper air, converting it into oxides of nitrogen; these, in turn, combine with and destroy
the protective ozone in the Earth's stratosphere. The surface of the Earth is shielded from
deadly solar ultraviolet radiation by a layer of ozone so tenuous that, were it brought down to
sea level, it would be only 3 millimeters thick. Partial destruction of this ozone layer can have
serious consequences for the biology of the entire planet.
These discoveries, and others like them, were made by chance. They were largely unexpected.
And now another consequence -- by far the most dire -- has been uncovered, again more or
less by accident.
The U.S. Mariner 9 spacecraft, the first vehicle to orbit another planet, arrived at Mars in late
1971. The planet was enveloped in a global dust storm. As the fine particles slowly fell out, we
were able to measure temperature changes in the atmosphere and on the surface. Soon it
became clear what had happened:
The dust, lofted by high winds off the desert into the upper Martian atmosphere, had
absorbed the incoming sunlight and prevented much of it from reaching the ground. Heated
by the sunlight, the dust warmed the adjacent air. But the surface, enveloped in partial
darkness, became much chillier than usual. Months later, after the dust fell out of the
atmosphere, the upper air cooled and the surface warmed, both returning to their normal
conditions. We were able to calculate accurately, from how much dust there was in the
atmosphere, how cool the Martian surface ought to have been.
Afterwards, I and my colleagues, James B. Pollack and Brian Toon of NASA's Ames Research
Center, were eager to apply these insights to the Earth. In a volcanic explosion, dust aerosols
are lofted into the high atmosphere. We calculated by how much the Earth's global
temperature should decline after a major volcanic explosion and found that our results
(generally a fraction of a degree) were in good accor4 with actual measurements. Joining
forces with Richard Turco, who has studied the effects of nuclear weapons for many years, we
then began to turn our attention to the climatic effects of nuclear war. [The scientific paper,
"Global Atmospheric Consequences of Nuclear War," was written by R. P. Turco, 0. B. Toon, T. P.
Ackerman, J. B. Pollack and Carl Sagan. From the last names of the authors, this work is
generally referred to as "TTAPS."]
We knew that nuclear explosions, particularly groundbursts, would lift an enormous quantity
of fine soil particles into the atmosphere (more than 100,000 tons of fine dust for every
megaton exploded in a surface burst). Our work was further spurred by Paul Crutzen of the
Max Planck Institute for Chemistry in Mainz, West Germany, and by John Birks of the University
of Colorado, who pointed out that huge quantities of smoke would be generated in the
burning of cities and forests following a nuclear war.
Croundburst -- at hardened missile silos, for example -- generate fine dust. Airbursts -- over
cities and unhardened military installations -- make fires and therefore smoke. The amount of
dust and soot generated depends on the conduct of the war, the yields of the weapons
employed and the ratio of groundbursts to airbursts. So we ran computer models for several
dozen different nuclear war scenarios. Our baseline case, as in many other studies, was a 5000-
megaton war with only a modest fraction of the yield (20 percent) expended on urban or
industrial targets. Our job, for each case, was to follow the dust and smoke generated, see how
much sunlight was absorbed and by how much the temperatures changed, figure out how the
particles spread in longitude and latitude, and calculate how long before it all fell out in the air
back onto the surface. Since the radioactivity would be attached to these same fine particles,
our calculations also revealed the extent and timing of the subsequent radioactive fallout.
Some of what I am about to describe is horrifying. I know, because it horrifies me. There is a
tendency -- psychiatrists call it "denial" -- to put it out of our minds, not to think about it. But
if we are to deal intelligently, wisely, with the nuclear arms race, then we must steel ourselves
to contemplate the horrors of nuclear war. The results of our calculations astonished us. In the
baseline case, the amount of sunlight at the ground was reduced to a few percent of normal-
much darker, in daylight, than in a heavy overcast and too dark for plants to make a living
from photosynthesis. At least in the Northern Hemisphere, where the great preponderance of
strategic targets lies, an unbroken and deadly gloom would persist for weeks.
Even more unexpected were the temperatures calculated. In the baseline case, land
temperatures, except for narrow strips of coastline, dropped to minus 250 Celsius (minus 13
degrees Fahrenheit) and stayed below freezing for months -- even for a summer war. (Because
the atmospheric structure becomes much more stable as the upper atmosphere is heated and
the low air is cooled, we may have severely underestimated how long the cold and the dark
would last.) The oceans, a significant heat reservoir, would not freeze, however, and a major ice
age would probably not be triggered. But because the temperatures would drop so
catastrophically, virtually all crops and farm animals, at least in the Northern Hemisphere,
would be destroyed, as would most varieties of uncultivated or domesticated food supplies.
Most of the human survivors would starve.
In addition, the amount of radioactive fallout is much more than expected. Many previous
calculations simply ignored the intermediate time-scale fallout. That is, calculations were made
for the prompt fallout -- the plumes of radioactive debris blown downwind from each target-
and for the long-term fallout, the fine radioactive particles lofted into the stratosphere that
would descend about a year later, after most of the radioactivity had decayed. However, the
radioactivity carried into the upper atmosphere (but not as high as the stratosphere) seems to
have been largely forgotten. We found for the baseline case that roughly 30 percent of the
land at northern midlatitudes could receive a radioactive dose greater than 250 rads, and that
about 50 percent of northern midlatitudes could receive a dose greater than 100 rads. A 100-
rad dose is the equivalent of about 1000 medical X-rays. A 400-rad dose will, more likely than
not, kill you.
The cold, the dark and the intense radioactivity, together lasting for months, represent a
severe assault on our civilization and our species. Civil and sanitary services would be wiped
out. Medical facilities, drugs, the most rudimentary means for relieving the vast human
suffering, would be unavailable. Any but the most elaborate shelters would be useless, quite
apart from the question of what good it might be to emerge a few months later. Synthetics
burned in the destruction of the cities would produce a wide variety of toxic gases, including
carbon monoxide, cyanides, dioxins and furans. After the dust and soot settled out, the solar
ultraviolet flux would be much larger than its present value. Immunity to disease would
decline. Epidemics and pandemics would be rampant, especially after the billion or so
unburied bodies began to thaw. Moreover, the combined influence of these severe and
simultaneous stresses on life are likely to produce even more adverse consequences --
biologists call them synergisms -- that we are not yet wise enough to foresee.
So far, we have talked only of the Northern Hemisphere. But it now seems - unlike the case of
a single nuclear weapons test -- that in a real nuclear war, the heating of the vast quantities of
atmospheric dust and soot in northern midlatitudes will transport these fine particles toward
and across the Equator. We see just this happening in Martian dust storms. The Southern
Hemisphere would experience effects that, while less severe than in the Northern Hemisphere,
are nevertheless extremely ominous. The illusion with which some people in the Northern
Hemisphere reassure themselves -- catching an Air New Zealand flight in a time of serious
international crisis, or the like -- is now much less tenable, even on the narrow issue of
personal survival for those with the price of a ticket.
But what if nuclear wars can be contained, and much less than 5000 megatons is detonated?
Perhaps the greatest surprise in our work was that even small nuclear wars can have
devastating climatic effects. We considered a war in which a mere 100 megatons were
exploded, less than one percent of the world arsenals, and only in low-yield airbursts over
cities. This scenario, we found, would ignite thousands of fires, and the smoke from these fires
alone would be enough to generate an epoch of cold and dark almost as severe as in the 5000
megaton case. The threshold for what Richard Turco has called The Nuclear Winter is very low.
Could we have overlooked some important effect? The carrying of dust and soot from the
Northern to the Southern Hemisphere (as well as more local atmospheric circulation) will
certainly thin the clouds out over the Northern Hemisphere. But, in many cases, this thinning
would be insufficient to render the climatic consequences tolerable -- and every time it got
better in the Northern Hemisphere, it would get worse in the Southern.
Our results have been carefully scrutinized by more than 100 scientists in the United States,
Europe and the Soviet Union. There are still arguments on points of detail. But the overall
conclusion seems to be agreed upon: There are severe and previously unanticipated global
consequences of nuclear war-subfreezing temperatures in a twilit radioactive gloom lasting for
months or longer.
Scientists initially underestimated the effects of fallout, were amazed that nuclear explosions in
space disabled distant satellites, had no idea that the fireballs from high-yield thermonuclear
explosions could deplete the ozone layer and missed altogether the possible climatic effects of
nuclear dust and smoke. What else have we overlooked?
Nuclear war is a problem that can be treated only theoretically. It is not amenable to
experimentation. Conceivably, we have left something important out of our analysis, and the
effects are more modest than we calculate. On the other hand, it is also possible-and, from
previous experience, even likely-that there are further adverse effects that no one has yet been
wise enough to recognize. With billions of lives at stake, where does conservatism lie-in
assuming that the results will be better than we calculate, or worse?
Many biologists, considering the nuclear winter that these calculations describe, believe they
carry somber implications for life on Earth. Many species of plants and animals would become
extinct. Vast numbers of surviving humans would starve to death. The delicate ecological
relations that bind together organisms on Earth in a fabric of mutual dependency would be
torn, perhaps irreparably. There is little question that our global civilization would be
destroyed. The human population would be reduced to prehistoric levels, or less. Life for any
survivors would be extremely hard. And there seems to be a real possibility of the extinction
of the human species.
It is now almost 40 years since the invention of nuclear weapons. We have not yet experienced
a global thermonuclear war -- although on more than one occasion we have come
tremulously close. I do not think our luck can hold forever. Men and machines are fallible, as
recent events remind us. Fools and madmen do exist, and sometimes rise to power.
Concentrating always on the near future, we have ignored the long-term consequences of our
actions. We have placed our civilization and our species in jeopardy.
Fortunately, it is not yet too late. We can safeguard the planetary civilization and the human
family if we so choose. ccccccccccc
For this reason I became a life member of The Alliance Of Atomic Veterans and why I am proud to have been arrested over 20 times by the Whackinhuts at Test Site Mercury in the State of Neveada. On sacred land stolen from the Western Shoshonies by the DOD and DOE I know as Sagan stated above-There is no more important or more urgent issue. be active or radioactive you have a voice.
Edited 4 time(s). Last edit at 12/23/2016 04:36AM by riverhousebill.
Re: The World After Nuclear War Carl Sagan
Date: January 01, 2017 12:02AM
As Zippy would say, Are We Safe Yet?
There are now more than 50,000 nuclear weapons, more than
13,000 megatons of yield, deployed in the arsenals of the United States and the Soviet Union
-- enough to obliterate a million Hiroshimas.
And Trump says let the arms race begin.
We spend 2 million dollars an hour 48 million every 24 hr just to maintain
not counting new weapons of mass destruction.
Nuckes are not defensive or ofensive weapons,Just mans insanity and a money maker for the top eliteist Tick toc. be active or radioactive lift a finger off the trigger. Trump is insane and he has the codes as of 20th of Jan.
Re: The World After Nuclear War Carl Sagan
Date: August 10, 2017 09:57AM
You all have heard me harping for a while on this nuclear threat one of my few fears on our dear planet. I have known for some time how this nuclear sabor ratling could turn into a runaway train, we members of the Aliance Of Atomic Veterans have been in been going over this threat for many decades now, I think we are now at that point where
the brakes have failed, after reading Ambassador Rhichards take id say where on a runaway train, Im fearful for the children and future generations at this point.
Its been said that north Korea only has about 17 warheads like thats not enough to end the whole show, bet your ass it is kids, Ill post again part of Carl sagans math on limited nuclear war.
read first Ambassador Rhichardsons take on Trumps lose cannon! it confirms what I have been posting on Nuclear war by accident, we have a run away train now because of Trumps igorance. we are on the eve of destruction and I dont think Im being an alarmist.
All we can do at this point i gusse is call your elected congress of cowards and senate of snakes and tell them to gag Trump and ask north korea if they realy have to bomb the white house and leave the rest of the world out of this!
we can rebuild the white house but not the planet!
This is getting very scary may some logical sense prevail somewhere in this end game threat. The survivors of Hirshimo enveyed the dead,
Nam Mo AH DI DA PHAT
CBS News/August 9, 2017, 7:11 PM
Richardson: North Korea catching U.S. off guard "a massive intelligence failure"
The war of words between North Korea and the U.S. is escalating. Last week, the United Nations Security Council approved new sanctions against the country, which responded with a vow of "thousand-fold revenge" against the U.S.
On Tuesday, an intelligence report that came to light concluded that North Korea has the ability to build a nuclear warhead small enough to fit on top of a ballistic missile. President Trump then warned North Korea, vowing "fire and fury like the world has never seen" if threats against the U.S. continue.
CBS News' Anthony Mason spoke with Bill Richardson, former U.S. ambassador to the United Nations and an expert on North Korea, about the increasing tensions -- and where we go from here.
What follows is a transcript of the interview, which aired August 9, 2017, on the "CBS Evening News."
ANTHONY MASON: Mr. Ambassador, where do we go after "fire and fury"? What's the best option for the U.S. now?
BILL RICHARDSON: The best option is diplomacy, the best option is continued sanctions, see if they work. Continue to pressure China, continue the military exercises, but find a way to talk to the North Koreans.
Former U.S. Ambassador to the U.N. Bill Richardson
MASON: But Kim Jong Un hasn't shown a lot of interest in diplomacy to this point.
RICHARDSON: We don't know what he wants. He's an unpredictable character. We don't know what his intentions are. He wants to stay in power. But I think in the end, once he knows that he can hit the United States with a missile, he can start negotiating. That's the way his father was. But I think keeping the talk about preemptive military strikes and the president's very incendiary statement, which was not helpful, is not the way to go.
MASON: What do you make of North Korea's threat towards Guam?
RICHARDSON: This is part of their foreign policy. However, the intensity of the attack, the specificity bothers me. The fact that the foreign minister himself -- who's a reasonable guy, I've dealt with him, Foreign Minister Re -- was so intense that I'm just a little worried that that intensity is a little too strong. What you don't want to have is a miscalculation.
MASON: What's the risk here that we could start a war by accident?
RICHARDSON: The risk is strong. A fishing boat is shot by the North Koreans, airspace is invaded and the North Koreans react, the South Koreans react -- everybody's trying to out-macho each other.
MASON: Lastly, Mr. Ambassador, U.S. intelligence seemed to be surprised by the technical advances in North Korea. Does that worry you?
RICHARDSON: That worries me because we should've been on this long ago. We should consider finding ways to put more intelligence, over-flights, more spies, because we were caught off guard. North Korea was way more advanced than our intelligence people told us. That's a massive intelligence failure that should never happen again.
MASON: Ambassador Bill Richardson, thank you so much for being with us.
RICHARDSON: Thank you.
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