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Nuclear
Winter Disaster
A Nuclear Winter Could Last Years After an All-Out War Between Russia
and the US
By Isobel Whitcomb - Live Science
Contributor
An all-out nuclear war would cause
freezing summers and famine across the globe.
If Russia and the United States launched an all-out nuclear war,
it would spell disaster for everyone on Earth, a new study suggests.
Not only would explosions, fires and radiation exposure kill
millions in targeted cities, but a "nuclear winter" lasting months to
years would also drastically alter the Earth's climate, causing freezing
summers and worldwide famine.
The Cold War may be over, but nuclear bombs are still uniquely destructive,
and there's more than enough of them to cause climate catastrophe, said study co-author
Alan Robock, an environmental scientist at Rutgers University in New
Jersey.
"People think that nuclear
weapons are just bigger bombs," he told Live Science.
But they're not. When a nuclear bomb explodes, one-third of its
energy goes into an immediate explosion of heat and light, according to a review published in the journal WIREs
Climate Change.
An aftershock follows this explosion, leveling any structures
around the detonation and creating piles of kindling ready to catch fire.
Then, as fires rage, smoke billows into the atmosphere.
While rain would wash out some of that smoke, much of it would
drift into the stratosphere, where it could linger above the clouds, blotting
out the sun. That's what would cause nuclear winter.
The authors of the new study, published July 23 in the Journal of Geophysical Research: Atmospheres, used modern climate
models to calculate the effects of smoke from nuclear explosions on Earth's
temperature, wind patterns and more.
Their study wasn't the first to model the effects of nuclear
winter; in 2007, a team of researchers led by Robock ran a similar simulation.
However, this new study looked at Earth in higher resolution
than the earlier research, said Robock.
The recent research also looked at more locations and included
processes not described by the previous model, like the effects of soot on
atmospheric chemistry and the influence of nuclear winter on the oceans.
Even with the updated calculations, the outcome of nuclear
winter was bleak. That gives Robock more confidence that the outcomes suggested
by these models are accurate predictions he said.
"People criticize models because
they're imperfect," Robock said, "but if you can reproduce the model,
you can have confidence in your result."
"There really would be a nuclear
winter with catastrophic consequences," Joshua Coupe, a doctoral student in
atmospheric science at Rutgers University and lead author of the study, said in
a statement.
The researchers found that if the U.S. and Russia were each to
launch their entire nuclear arsenals at one another, soot would drift high into
the atmosphere, blotting out the sun for months to years.
Summers would become a thing of the past, with temperatures
throughout much of the Northern Hemisphere dipping below freezing year-round.
Growing seasons would be cut by 90%, and most of the world would
be plagued by famine.
In addition to dropping surface temperatures, nuclear winter
would have a major impact on everything from ocean currents to the jet stream.
The study's model predicted a seven-year-long El NiƱo, a normally yearlong weather pattern in the Pacific Ocean
that usually occurs only every three to seven years.
It leads to either drought or extreme rainfall in affected
regions.
During a nuclear winter, people turning to the oceans to
supplement dwindling crops would be disappointed, as much of the ocean's
biodiversity would also disappear.
Finally, as if the effects on climate weren't enough, soot would
poke huge holes in the ozone layer, bombarding the surface of Earth with
ultraviolet radiation.
This isn't the first time scientists have warned of the
potentially disastrous climatic consequences of nuclear war.
In the early 1980s, the height of the nuclear arms race,
scientists (including astronomer Carl Sagan) first hypothesized that smoke from
nuclear explosions could blot out the sun, drastically altering Earth's
climate.
The term "nuclear winter" was coined in 1983, when
a landmark study in the journal Science
calculated that temperatures could fall below freezing in the middle of
continents.
Because of the international campaign to abolish nuclear
weapons, nuclear arsenals have decreased over time.
Whereas there were more than 50,000 nuclear weapons worldwide in
the 1980s, there are now a comparatively small 8,500 worldwide, Robock said.
But that doesn't mean the threat is gone.
In fact, "it's gotten
worse," Robock said. "Before, there were only two countries
with nuclear arsenals" (the U.S. and Russia).
Now, there are nine, according to the Federation of American Scientists.
"The problem isn't solved," Robock said. "Even
though the arsenals have gone down, it's still enough to create a nuclear
winter."
Originally published on Live Science.
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