Doomsday event

Doomsday event facts,

A doomsday event is a specific plausibly verifiable or hypothetical occurrence which has an exceptionally destructive effect on the human race. The final outcomes of doomsday events may range from a major disruption of human civilization, the extinction of humanity, the extinction of all life on the planet Earth, the destruction of the planet Earth, the annihilation of the Solar system, to the annihilation of our galaxy or even the entire universe.

Even though the term "doomsday" is taken from Christian eschatology referring to the Last Judgment, the term "doomsday event" as used here refers to alleged realistic dangers from natural or man-made causes, to be distinguished from catastrophic events in religious eschatology understood as an act of divine retribution or unalterable fate.

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Scenarios

Doomsday events may include, but are not limited to:

Natural occurrences

These include:

A sudden change in the physical constants governing the universe, such as that created by a vacuum metastability event.

A close approach of a black hole to the solar system.

A gamma ray burst or other devastating blast of cosmic radiation. One especially deadly hypothesized source is a hypernova, produced when a hypergiant star explodes and then collapses, sending vast amounts of radiation sweeping across hundreds or even thousands of lightyears of space. Hypernovas have never been observed; however, a hypernova may have been the cause of the Ordovician-Silurian extinction events. The nearest hypergiant is thought to be Eta Carinae, approximately 8,000 light-years distant.

A drastic and unusual decrease or increase in Sun's power output; a solar superstorm leading to partial/complete electrical/technological death of human civilization.(See Solar Flare).

Abrupt geomagnetic reversal and/or drastic decrease of magnetic field of the planet Earth. Consequences can be the same as in the cases of cosmic radiation or solar radiation blasts.

The solar system passing through a cosmic dust cloud, leading to a severe global climate change.

An abrupt repositioning of Earth rotation axis. It could be caused by extremely powerful internal geological or/and external cosmic factors. If it happens abruptly (and not slowly within a very prolonged interval of time) it will generate enormous multiple earthquakes, multiple volcano eruptions, a hypercane or multiple megacyclones, giant tidal waves and megatsunamis all around the globe.

An impact event causing a collision (or extremely close passage) of a large meteorite, asteroid or comet. A common theory postulates that the extinction of the dinosaurs occurred approximately 65 million years ago as a result of the Cretaceous-Tertiary extinction event when a large asteroid struck the earth, producing atmospheric dust which blocked solar energy and caused a significant lowering of temperatures worldwide("nuclear winter"). Evidence for this theory includes a sedimentary layer of iridium in the geological record and a large crater in the area of Chicxulub, Mexico. The Tunguska event (1908) was on a much smaller scale. In the case of a close passage of an object(a large asteroid, comet or planet) with a significant gravitational impact on Earth, the consequences could be the same as in the case of an abrupt repositioning of Earth rotation axis. And such a repositioning of the axis would not necessarily have to take place for the earth to see the same global effects.

A geological event such as massive flood basalt, volcanism, or the eruption of a supervolcano leading to the so called nuclear winter. One such event, the Toba Eruption, occurred in Indonesia about 71,500 years ago. According to the Toba catastrophe theory, the event may have reduced human populations to only a few tens of thousands of individuals. Yellowstone Caldera is another such supervolcano, having undergone 142 or more caldera-forming eruptions in the past 17 million years.. Massive volcano eruption(s) will produce extraordinary intake of volcanic dust, toxic and greenhouse gases into the atmosphere with serious effects on global climate(towards extreme global cooling(nuclear winter when in short term and ice age when in long term) or global warming (if greenhouse gases prevail)).

An exceptionally devastating hypercane probably combined with global dust storm, taking up to the atmosphere enormous quantities of dust.

Severe climate change due to any or a combination of the above mentioned events. Also it could be caused even solely by drastic changes in ocean currents pattern. In general terms it will be towards extreme global cooling down(nuclear winter when in short term and ice age when in long term) or global warming up of the atmosphere and hydrosphere of the Earth, together with additional malignant effects on global and local precipitation and air circulation patterns. All these climate changes together will have devastating effects on human civilization.

A global pandemic (assuming that the causing agent of the pandemic would have a natural origin) with very high or even 100% mortality rate.

Hostile Extraterrestrial Life

Accidental extinction through the actions of non-hostile (but unsympathetic) extraterrestrial life

Human-made events

doomsday device

These include:

Depletion of important natural resources, assuming that alternatives are not found.

Gradual and relatively "slow" but drastic reduction of the world population through economic means such as mass unemployment, malnutrition and starvation, medical system failure and enormous increase of mortality due to lack of treatments for common lethal diseases.

A global pandemic with very high or even 100% mortality rate caused by a human-made infectious agent, which could be released among population on purpose. The source could be an individual, a laboratory workers group, a terrorist group, governmental or international organization.

A nuclear, chemical, or biological war. A "softer" and "stealthier" case of each of these 3 types of warfare could be nuclear, chemical, or biological terrorism. Again the source could be an individual, a laboratory workers group, a terrorist group, governmental or international organization.

A cybernetic revolt.

Precautions

Some precautions that people are already taking for this event include:

The Svalbard Global Seed Vault is a vault buried 400 feet inside a mountain in the Arctic with over ten tons of seeds from all over the world. 100 million seeds from more than 100 countries were placed inside as a precaution to preserve all the world’s crops. A prepared box of rice originating from 104 countries was the first to be deposited in the vault, where it will be kept at minus 18C (minus 0.4F). Thousands more plant species will be added as organizers attempt to get specimens of every agricultural plant in the world. Cary Fowler, executive director of the Global Crop Diversity Trust said that by preserving as many varieties as possible, the options open to farmers, scientists and governments were maximised. “The opening of the seed vault marks a historic turning point in safeguarding the world’s crop diversity,” he said. Even if the permafrost starts to melt, the seeds will be safe inside the vault for up to 200 years. Some of the seeds will even be viable for a millennium or more, including barley, which can last 2,000 years, wheat 1,700 years, and sorghum almost 20,000 years.

The Lifeboat Foundation has raised hundreds of thousands of dollars for numerous projects to prevent disasters such as asteroids, grey goo, and so forth.

(source:wikipedia)