The realms of science fiction have been scoffed at by many, but a lot of what writers have said has transpired in later times. Who know what the future holds? So, this may be an ELE for Sci-fi fans, but we are discovering planetary systems on a regular basis now and the odds of life existing elsewhere are increasing steadily. We would like to think that a species able to cross the vastness of outer-space and reach us would not be aggressive monsters wishing to conquer, enslave or destroy us. Who would want to come all that way just to be so vile? After all, when Europeans first discovered America, that was a peaceful process, wasn’t it?

Whether this would be your ELE of choice might depends on many things. Firstly, is it going to be quick and painless? If Earth is making way for a new interstellar highway it will be over in an instant. However, War of The Worlds and others such stories have it another way, and we could even end up on the plates of our conquerors if you are to believe TV series like “V”. As for yet another Dalek Invasion of Earth - No thank you!

Watch the Earth destroyed by an alien laser

A robot takeover of the planet is the much loved premise of many a sci-fi fable, from the aggressive Terminators, through Skynet to the benign sentience of the beings in Artificial Intelligence. But how likely is it? After all machines follow our instructions, they don’t actually think for themselves, do they?

The simple answer is not yet, but watch this space. The main thrust of research in to artificial intelligence is to create a machine that can solve problems not only independently of human intervention, but crucially, solve these problems creatively. When that happens some say that we are up the creek without a paddle.

Watch a possible robot warrior of the future

We, humanity, are unique in one thing. We alone among all the fauna of the planet have devised a way to wipe ourselves off the face of the planet swiftly and horribly. The intelligence that has enabled us to do this is what sets us apart from all other animals of Earth - and we think we’re special. There have been two instances of bombs of this nature set off in a war scenario - and apologists for this aside - Hiroshima and Nagasaki triggered the most obscene arms race the world has ever seen.

An ELE of choice? Well, you would have to hope that you were as near to the epicenter as possible if there was a large scale nuclear war because you wouldn’t have a very happy time of it if you survived (no matter what “Jericho” maintains!). If the radiation didn’t get you as a survivor, then starvation will as the bombs will create so much dust that the sun will not be able to penetrate the atmosphere for several years. This will create what is known as a nuclear winter, where crops will not grow and the food chain will effectively collapse. Deeply unpleasant.

Watch a possible World War Three scenario

Disease microbes - you can’t see them, you can’t smell them and they give no warning. However, they can build themselves up in to unspeakable numbers over the course of hours or days and they are designed to take full advantage of any weakness their enemies (us!) may have! In the fourteenth century the Black Death arrived in Europe and destroyed over a third of the population in a matter of years - and each time I t reappeared it had a similar effect.

We probably don’t have to worry about Bubonic Plague. However, the big frightener at the moment is something we don’t really seem to be taking seriously - and that is influenza. In 1918 a strain of the flu killed fifty million people worldwide. We had the last global flu epidemic over forty years ago and another one is long overdue. Estimates say the next one could be worse than the 1918 disaster. Plus diseases have been made in to weapons, such as anthrax. Old friends like TB are developing resistance to antibiotics. As an ELE this would not be a pleasurable - or a pretty - way to go. No thank you!

Watch Two Epidemic Scenarios for the USA

For any sticklers out there, yes, strictly speaking we in fact still inhabit the Ice Age. As a species we haven’t been around for very long and our records go back six thousand years ago, getting less and less dependable as we go back - in scientific terms. What we are in now is an interstadial period. That means a warmer period and it is something that has lasted around twelve thousand years. Plenty of time for us to get comfortable and think that our climate is steady and reliable. Time to think again!

Now for the scary bit. Sooner or later each interstadial period finishes and we go back to being in a cold weather time - a stadial period. The Ice Age has worked like this for some two million years. If the freezing conditions were to return it would kill most plants and animals in the zones that it would affect - and that is where you live! Some scientists theorize that the North Atlantic Current could close down because of the current warm period. The Ice Age could come back within a few years (years, not hours as portrayed in The Day After Tomorrow). As an ELE this could be quite effective, depending on how cold it gets and where. Personally, I hate the cold so this would most certainly not be my ELE of choice!

More About Global Cooling

Scientists have been taking samples of ice cores and sediment from the seas for more than a few decades now and what they have discovered has shown that the world’ climate can change dramatically over a very short space of time. This short space of time is normally just a few decades and should our own climate change as it has done it the past, the consequences could be extremely serious for humanity and the flora and fauna that surround us.

We are in the age of fossil fuel and the over the last two hundred years we have burned so much fossil fuel that the amount of carbon dioxide has risen drastically in our atmosphere. This could heat the planet up so much that much of our land will become uninhabitable and a great deal of it could be lost by rising oceans as the ice caps melt. As an ELE this is a long and lingering one, so not one for the author!

More about global warming if you want to get really depressed

One thing we should get clear right from the beginning is that the term supervolcano was coined by the BBC in the year 2000. Vulcanologists and geologists would not dream of using such a crass term - except when they make public appearances and want us to understand what they are going on about. They would call it a super eruption, which doesn’t quite have the same impact - at least in terms of words!

Yellowstone Park in the USA is an example of a volcano that could cause a super eruption. Every six hundred thousand years or so it has done so and is due to pop pretty soon now (give or take a few tens of thousands of years). If it erupted tomorrow it would be the end of civilization as we know it and would almost certainly cause a new Ice Age. As an ELE it is a slow burn, but one that nonetheless could threaten life on the planet.

See What Would happen if Yellowstone erupted

Not so much when stars collide, but when they collapse. Some of the stars in the galaxy are so huge that when they collapse they send out huge levels of gamma rays. Gamma rays are - as far as we know - the most dangerous form of radiation. Scientists have monitored the activity of gamma rays and they are when the activity increases it is known as a Gamma Ray Burst (GRB).

The Milky Way is a big place, bigger than anyone can comprehend really. However, were a Gamma Ray Burst, by some infinitesimal chance, to be directed at Planet Earth (and it could happen, ladies and gentlemen!) then it would irradiate the entire planet, much like we do to our food in a microwave oven. Some scientists even believe that the mass extinction of the Ordovician era - which took place about four hundred and fifty million years ago - was caused by a GRB. As an ELE it would be thorough, but possibly extremely painful! Choose this only if your center of population is directly above the blast!

Watch the earth destroyed by a GRB

Otherwise known as a bolide impact, these happen every day - however, usually the objects are so small they burn up in our atmosphere. Humanity has done a great deal to litter outer space with man made objects but it is a well known fact that our little blue planet is not moving through empty space on its journey around the sun.

Around sixty five million years ago one of these babies hit the Yucatán Peninsula in Mexico. The dinosaurs were, officially, dust. A great shame, because they had been around for a great deal of time. In fact, in one shape or form they had been around for one hundred and twenty million years at least. By comparison our species has been around the blink of an eye. If one can do for them, it could do for us too! As an ELE this would be spectacular, especially from space. Of course we have all seen films that have the heroes blow up the asteroids one way or another before they can truly kill off the entire species, but do we really have that capability?

See an asteroid hit the Earth

Of all the possible ELEs listed above, many have one thing in common - us! Is it possible that it is humanity that is - if only even metaphorically- the greatest ELE in the history of our planet? A distinct possibility!

After All - Who Want To Live Forever?