If you believe the Mayan Apocalypse theory, the world is due to end in one month’s time.
The doomsday scenario suggests the day to end all days will be December 21.
This is because that date – the winter solstice - is the final one in the calendar used by the once great Central American civilisation.
Experts - and ethnic Mayans - agree that the 'end date' does not denote some kind of apocalypse, but instead a new period in the Mayan 'long count' calendar.
But what if some kind of apocalypse did occur?
Surprisingly, governments and other official organisations already offer advice on how to survive - even in the event of an attack by the living dead.
In recent years a scary number of new viruses – from SARS to Swine Flu - have threatened a human catastrophe.
Luckily, governments have been planning for the new plague ever since the 1918 influenza pandemic killed 50million people - five times as many as the First World War, which had just ended.
In the event of a huge outbreak, the World Health Organisation advises to first of all, if possible, immunise yourself against whatever is raging.
It is also worth getting a pneumonia vaccine because this is a common secondary infection.
Most deadly viruses are airborne – and passed by water droplets in our breath – so wearing a respirator is also suggested.
Likewise, wash your hands and wear gloves. Goggles are a good idea too because contaminated droplets can enter our eyes.
Social distancing is also advised. So lock yourself away - with a supply of food, clean water, medicine and cash – and wait out the epidemic.
The Cold War between the Soviet Union and Nato has long since ended.
But fresh nuclear threats are possible with a host of new countries, including India, Pakistan and, one day possibly Iran possessing such weapons.
Longstanding advice from various government agencies includes:
- Seeking shelter (ideally below ground and surrounded by thick concrete)
- Rationing supplies of food, water, fuel, medicine and clothing
- Wearing hats and goggles and exposing as little skin to the air as possible
- Following the news and evacuating if ordered
Dedicated survivalists also suggest having a Geiger counter to measure radiation and an understanding of the different types of radiation and radioactive materials.
Guarding your electrical items against the possibility of being knocked out by an exploding nuclear bomb’s electromagnetic pulse is also a good idea.
The easiest – and cheapest - way to do this is unplug devices and wrap them in a space blanket, which may also be necessary to keep warm.
Some radiation burns can be treated by immersing in water and covering with baking powder and Vaseline.
After six months it may be safe to leave.
An asteroid strike has the potential to wipe out human civilisation. The last one killed the dinosaurs and caused the Ice Age.
There is very little official advice on how to survive a super-comet hitting Earth - although NASA tracks all such objects within the solar system.
In the 'planet killer' range - above 3,300ft in size, NASA has found almost all such objects in the solar system.
However, if we are going to be hit, we should know within six months to a year of it happening.
This should give you time learning about asteroids, develop survival skills and set up a fully stocked shelter as far below ground as possible.
Survivalists suggest avoiding public shelters, where disease could be rife.
The location of your personal shelter should, ideally, be close to the coast, which will be much warmer than freezing interiors.
Also, it should be nowhere near a fault line or volcano as the impact is likely to cause earthquakes and eruptions of lava.
For these reasons, Britain is one of the best places to be.
As sun-blocking ash will shroud the earth, do not be tempted to leave your bunker for six months.
The planet will not start warming up until four years after the strike.
GLOBAL WARMING AND RISING SEA LEVELS
Climate change is indeed a threat. But it is unlikely to spark a full-scale apocalypse.
However, if the polar ice caps melted, sea levels would rise dramatically and huge swathes of land could be deluged by water.
In the long term, governments around the world recognise the need to build greater sea defences.
But this may not help with a sudden catastrophic and global sea flood.
Survivalists generally agree that living on high land is a good idea.
However, enough ice water in the sea could possibly reverse the Gulf Stream and Britain, being relatively far north, could enter a new ice age.
Also, rising temperatures could cause places further south to become arid and uninhabitable.
Therefore, moving to Lake Titicaca, which straddles the mountainous border between Peru and Bolivia, might be a good bet.
At 12,464ft up, it’s high up enough not to be flooded by seawater. It’s far south enough not to be unbearably cold. And its high altitude means it won’t get too hot either.
Despite being extremely unlikely that the undead might roam the earth killing us off, you may be surprised to learn that official plans have been prepared just in case.
The U.S. Centres for Disease Control and, more bizarrely, Bristol City Council, have provided advice with dealing with reanimated corpses.
The English local authority suggests arming yourself with a stun gun, handcuffs and a protection suits to both defeat and avoid the plague of the living dead.
According to CDC plans, they “would conduct an investigation much like any other disease outbreak” if ‘zombies did start roaming the streets’.
So much like the advice with dealing with a plague, the best options for survival are to isolate our families and stocking up with supplies. CDC director Dr Ali Khan notes: "If you are generally well equipped to deal with a zombie apocalypse you will be prepared for a hurricane, pandemic, earthquake, or terrorist attack."