Doomsday: Inside Job

Earth is humanity’s cradle, but by no means can it completely harbour us from harm. Many risks threaten individual lives, but there are some catastrophic enough to wipe out entire species. Is it possible for the prolific human species to face extinction?

We knew the world would not be the same ... "Now I have become Death, the destroyer of worlds"...I suppose we all thought that, one way or another.

J. Robert Oppenheimer, director of the Manhattan Project

History
In 1933, Leó Szilárd proposed that free neutrons could be used to start a chain atomic reaction. In 1938, Otto Hahn and Fritz Strassmann found barium in a uranium solution bombarded with neutrons. The next year, World War II started, during which the United States undertakes the Manhattan Project. It produced the first working nuclear weapons (atomic bombs), one of which dropped on Hiroshima, Japan and another on Nagasaki (pictured above). These attacks caused Japan to surrender, ending the War.

Doomsday: High Impact

Earth is humanity’s cradle, but by no means can it completely harbour us from harm. Many risks threaten individual lives, but there are some catastrophic enough to wipe out entire species. Is it possible for the prolific human species to face extinction?

Impacts with space debris are truly spectacular events, as the size of the object belies the devastation they can wreak. Not only does an impact event obliterate the the area around it, rock can also be thrown high into the air and particularly large ones can change the very evolution of life.

History
After the birth of the solar system 4.6 billion years ago, its planets saw many planet-sized collisions. Mercury was hit by an object that formed the 1550km Caloris basin. Venus suffered a glancing blow that was enough to make it spin the other way. Mars saw an impact that created a crater the size of half the planet's surface.

Doomsday: Pandemic

Earth is humanity’s cradle, but by no means can it completely harbour us from harm. Many risks threaten individual lives, but there are some catastrophic enough to wipe out entire species. Is it possible for the prolific human species to face extinction?

It is not good to be sick. At this day and age, the practice of medicine ensures that people stand a good chance of survivng all common illnesses. However, some diseases do pop up which no medical literature covers and against which no treatments exist. The burden then falls to the rest of society to contain its spread as a pandemic as scientists work frantically to develop a cure...

History
The Bible describes ten 'plagues' that befell the citizens of Ancient Egypt. Subjecting the Israelites to slavery, the Jewish God was accounted to have exacted His vengeance. The tenth plague, which finally convinced the Pharaoh to release the Israelites, was one which killed all firstborn sons in the kingdom. It is known that it was common practice to feed the firstborn son a double helping of grain, and with the ruin of their crops from the previous hailstorm and locust plagues, they needed to draw from supplies stored underground.

Doomsday: Extreme Weather

Earth is humanity’s cradle, but by no means can it completely harbour us from harm. Many risks threaten individual lives, but there are some catastrophic enough to wipe out entire species. Is it possible for the prolific human species to face extinction?

Earth's climate is a complicated system, one which climatologists are still studying. Like in a car or computer, a minor change in one component can cause more major effects throughout. Although volcanoes can disrupt this delicate machinery, there are other factors which can plunge Earth into an ice age, some of which built in, others brought about by humans.

History
150 000 years ago, Earth orbited a little further from the Sun than normal. It went through a particularly severe ice age, where the human population dropped to as low as 2000 people.

Doomsday: She's Gonna Blow

Earth is humanity’s cradle, but by no means can it completely harbour us from harm. Many risks threaten individual lives, but there are some catastrophic enough to wipe out entire species. Is it possible for the prolific human species to face extinction?

Volcanoes cause much disruption in their own right. However, much larger supervolcanoes do exist, with as many as eleven likely hotspots found around the world. Should one erupt, the surrounding area will certainly be levelled and buried, and the broader world would go through an unseasonal winter.

History
There are countless examples of volcanic eruptions throughout human history, let alone throughout the life of planet Earth. A more famous one occurred in AD 79 when Mt. Vesuvius erupted. Nearby Pompeii and Herculaneum were buried under several metres of pumice, sudden enough to preserve the inhabitants in their original positions.

Doomsday: Sunfury

Earth is humanity’s cradle, but by no means can it completely harbour us from harm. Many risks threaten individual lives, but there are some catastrophic enough to wipe out entire species. Is it possible for the prolific human species to face extinction?

The Sun provides all living things with the heat (and, indirectly, food) needed to survive. Yet for all its needed sustenance, there are also times when it turns against life, in particularly spectacular fashion. Every 13 years it throws a tantrum of sorts, with the next one due on late 2012.

Doomsday: The Mayan Code

Earth is humanity’s cradle, but by no means can it completely harbour us from harm. Many risks threaten individual lives, but there are some catastrophic enough to wipe out entire species. Is it possible for the prolific human species to face extinction?

The Maya empire fell centuries ago, yet their work continues to intrigue to this day. Among many opinions of that work is the conclusion that the world will end on 21 December 2012. How well does that theory stand up to modern scrutiny?