Which has already become generally accepted estimate, by taking into the stratosphere of smoke and soot from large fires, caused by the explosion of 30 - 40 % accumulated in the world of nuclear warheads, resulting in a significant increase in the number of reflected sunlight, the temperature on the planet everywhere will fall to the Arctic. Such a change in the climatic conditions of life on Earth and is called nuclear winter.

The severity of nuclear winter depends on the following factors:

1. The amount of soot, which will arise and will be thrown into the troposphere in the case of large-scale nuclear war.
2. The impact of soot on the Earth's temperature.
3. The residence time of carbon black in the upper atmosphere.
4. The influence of cooling on human survival.

Given the uncertainty in the models, as well as the possibility of a protracted nuclear war and other causes darkening of atmosphere, we can assume the following theoretical options nuclear winter:

1. The temperature of one degree per year, do not have a major impact on the human population (as after the eruption of mount Pinatubo in 1991).

2. "Nuclear autumn" - the temperature decrease by 2-4 degrees Celsius in the next few years; crop failures, hurricanes.

3. "The year without summer" - intensive but relatively short cold during the year, the death of a significant part of the harvest, hunger and death of people from the cold in some countries. This occurred after major volcanic eruptions in the VI century ad, in 1783, in 1815.

"Ten years of nuclear winter" - falling of the temperature on Earth for 10 years by about 30 - 40 degrees C. This scenario assumes models nuclear winter. Snow in most parts of the planet, except for some Equatorial coastal areas. Mass deaths from starvation, cold, and the snow will accumulate and form a multimeter thickness, destroying buildings and blocking roads. Most of the population of the Earth will perish, but millions of people will survive and retain key technologies. Risks: the continuation of the war for the warm place, unsuccessful attempts to warm our planet with the help of new nuclear explosions and artificial volcanoes, the transition from unmanaged heating nuclear summer. However, even assuming this scenario, you find that only one of the world supply of cattle (which will freeze on their farms and will be stored in such natural "coolers") will last for years to feed all of humanity, and Finland has a strategic stock of food (grain) for 10 years.

A new ice age. Is hypothetical continuation of the previous scenario, in a situation when the reflectivity of the Earth increases due to snow, and start to grow new ice caps from the poles down to the equator. However, part of the land near the equator remains suitable for living and farming. The result civilization will have to radically change. It is hard to imagine a huge migration of peoples without wars. Many species will become extinct, but a significant part of the biosphere will survive, though people will destroy it even more ruthlessly in search of any food. People have gone through several ice ages, which could begin quite dramatically as a result of eruptions of corvocado and falling asteroids (the eruption of Toba, Latinskaya comet catastrophe).

6. Irreversible global cooling. It may be the next phase of the ice age (at worst-case scenario). On the whole planet on geologically long time there will be a temperature mode, as in Antarctica, the oceans will freeze, land covered with a thick layer of ice.
Only high-tech civilization that is able to build huge structures under the ice, can survive
this evil, but such a civilization could probably find a way to reverse this process. Life can survive only about geothermal sources on the seabed. The last time the Earth has entered into this state about 600 million years ago, i.e. before the release of animals on land, and were able to get out of it only through the accumulation of C02 in the atmosphere.

7. Finally, in case if the Sun refuse to Shine, the worst outcome would be to make the whole atmosphere in liquid nitrogen.

Integration of the damaging effects of weapons

Moderate scale nuclear winter, accompanied by mild radioactive damage, can give "synergistic" effect that extends beyond the power of even the most powerful nuclear winter alone.

For example, as already mentioned, in the case of "clean" nuclear winter, many people will be able to feed the cattle, which were frozen in the stalls and well preserved. In the case of radioactive contamination is not such a chance. The blast around the world will be destroyed houses, and where they will be saved, will be smashed Windows, and it will make more complex protection from radiation and cold.

Flushing radioactive forest is dangerous. These factors will increase with the destruction of the most valuable objects of infrastructure due to the direct action of damaging factors of nuclear weapons.

Nuclear winter as weapons

We can assume that if some force will aim to make nuclear winter artificially, it can be arranged, detonating hydrogen bomb in coal mines or in the taiga. This, perhaps, will give much greater emissions of soot attack on the city. If you install a hydrogen bomb with a timer for various periods of time, you can maintain nuclear winter indefinitely. Theoretically, this way you can achieve sustainable self-sustaining white-cold ball", reflecting the full sunlight, with a full freeze of the oceans.

Initiation of the eruption of cuervocon using nuclear weapons will lead to the analogue of the "nuclear winter" - to volcanic winter. Attempts to remedy the situation by using artificially created nuclear nuclear winter or summer, can only exacerbate the problem by switching climate in the mode of excitation.

Separately, you can select the theory of nuclear summer, which suggests that after a nuclear winter, and can be and instead of it, there will be a significant increase in the Earth's temperature, which can dangerously added to the existing global warming, placing it in the supercritical phase with growth of temperature on tens of degrees.

Factors that can lead to nuclear fly: the deposition of soot on glaciers; the formation of nitrogen oxides in the explosions that Deplete the ozone layer and leading to the extinction of vegetation, absorbing carbon dioxide; changing the albedo effect of desertification and emissions of carbon dioxide in fires. Also, will fail barrier, not giving water vapor to get into the stratosphere, and then when he turns back on, tens of billions of tons of water is locked in the stratosphere, and they can create the greenhouse effect in additional To 8 degrees of magnitude, according to Ronald in his article "Nuclear winter and other scripts. In addition, he suggests that nuclear winter can be used as a weapon, while the winner is the country which has accumulated the largest reserves of food and having the best warm accommodation.

Nuclear summer is much more dangerous nuclear winter because people survive in more cooling than heating (that is, if you take a room temperature of 20 C, the person tolerates frost on the street in - 50C, that is 70 degrees below, but will be able to withstand a temperature rise to no more than 30 degrees, i.e. not higher than 50 C. in Addition, the heating system can work offline (surviving forests as a source of firewood stove), and refrigerators require sustainable centralised infrastructure (production of refrigerators + electricity). Storing food with a sharp warming will be extremely difficult - they will rot, will be damaged by pests or will burn. Thus, nuclear summer creates a much greater risk of extinction than nuclear winter.

Feature of the global infection that it is evenly spread over the entire surface of the Earth and penetrate everywhere due to natural convection of the atmosphere and that it is so long that it cannot wait out in the existing offline now shelters.

Most known for this kind of scenario is the use of cobalt bombs, i.e. bombs with increased release of radioactive substances. Cobalt bombs are the hydrogen bomb, surrounded by a shell of cobalt-59 turning into a radioactive isotope cobalt-601. The project bombs that can infect the whole continents, suggested Leo Szilard in 1950. Cobalt-60 has a half-life of 5.26 year, so the pollution generated by them will be long and it will be difficult to wait in the bunker.