What If A Great Flood Happened On Earth?

What If a Great Flood Happened on Earth?

As a planet, we need water to survive. But, too much of it, and water can be deadly. Horror stories of divine floods pepper our mythology and religious texts, as sacred tales designed to warn people against attracting the wrath of whichever deity they devote themselves to… All the while playing on a shared, human fear of water. These flood narratives define the potential fury of all kinds of gods, and though today we know the facts behind why floods happen, this doesn’t change how dangerous they are.

Modern humans face a threat of flooding on a scale not seen since the thawing of the last ice age 11,000 years ago, thanks to the insidious danger of global warming. Shockingly, despite knowing that global flooding is becoming a reality, we are often caught ill-prepared for it when it happens. So, since we struggle to plan for even the more predictable disasters, it’s doubly frightening to think of what would happen if there really was a “great flood” of Biblical proportions. It’d surely be a tragic purge of life that we’d struggle to survive.

Since humans have always had to build around water – be that along rivers or on the coast – the threat of a destructive flood is especially high in those areas. Here, especially, water is both our salvation and damnation – it’s the essence of life itself, but also the bringer of death and destruction to plants, animals and human settlements. The floods from the stories are often attributed to somebody somewhere invoking the fury of a god. Be that in the book of Genesis, where everybody except for Noah and company are wiped out for their sins; or in Plato’s accounts of Greek mythology, where Zeus floods the Greek world for nine days and nights because he was tired of constant warfare. There’s also the even earlier Mesopotamian story of Gilgamesh, who built an Ark-like vessel; and, in Hindu texts, the first man is forewarned of a devastating flood by Vishnu. In all of these stories, a chosen someone is warned of impending doom by a more powerful force, allowing a select few to survive by means of a giant boat.

While the inspiration for our religious tales remains up for debate, a primary reason so many cultures have adopted these flooding stories is because there most likely have been devastating floods in the past. Greek philosophers were some of the first to speculate on this scientifically, after discovering sea fossils high up in the mountains. While these fossils could have been there because large parts of our land was once submerged, a “great flood” is a fairly logical conclusion to draw when one finds a fish hundreds of miles away from water.

The studying of flood narratives is widely considered a pseudoscience nowadays, but scientists can’t entirely disprove that there really was a great flood at one time or another, either. There are further theories for how it happened, though – including the Noah’s Flood Hypothesis, and the Comet Hypothesis. The first suggests that the ‘great flood’ refers to the melting of glaciers and sea ice at the end of the last ice age, which caused the Black Sea to overflow. While, the second argues that the catastrophic flooding was caused by one of a string of comets crashing into the ocean – and the tsunamis that followed. With leading scientists still trying to work out what actually constitutes a ‘great flood’, it feels not impossible that we might one day face another one. So, what could we realistically do about it?

‘Build a large boat’ seems to be the take-away from every single deluge myth and, as individuals, it’s still the best plan for the worst-case scenario. Get yourself plenty of floatation devices and inflatables, lots of canned food, fishing supplies, some form of shelter, and a method to filter water, and you could potentially ride out this particular apocalypse. The silver lining if your caught in a global flood is that, so long as you like seafood, there are still fresh things to eat. It’s also not impossible to grow plants on a boat, you’d just need some soil, fertilizer, and sunlight. And of course, we’d all have water in abundance, so long as we also all had heavy-duty desalination kits.

But boats aren’t so easy to come by. Unless it’s linked to how you make a living, owning a boat big enough to withstand a flood is only really a reality for the super-rich. With time to prepare, ala Noah, you could build yourself one – but not without a lot of help from a lot of other people. Even the most gifted shipbuilder can’t expect to build a viable vessel all on their own… But, say you did gather a team together, and you did start to erect an ark… the project would surely attract all sorts of attention – from local news companies dropping by to get the scoop on your reasons why, to local governments badgering you for proof of planning permission. Clearly, though, if there’s no divine element to the next ‘great flood’ (or, at least, none that you’re aware of) then you’re not likely to be involved in such a project. And those most prepared for total flooding really would be anyone who happens to be on a boat when the flood strikes, or anyone who’s wealthy enough and can get to their private yacht in time.

Either way, for the majority of the global population, gaining access to any kind of boat wouldn’t be an option. So, what then? First, head in-land and for high ground. In a flood brought on by climate change, scientists have already predicted exactly where the flooding would be worst; along coastal regions of Europe, the Americas, and parts of South East Asia. London, New York, Buenos Aires, and Hong Kong are just some of the hundreds of major cities which would be completely submerged. Metropolitan hubs that were once home to hundreds of thousands of people, would need to be quickly evacuated as their structures are saturated, and their foundations are wrecked. As a general rule, heading into the mountains is often a pretty good bet when the planet goes pear-shaped – and especially if waters are rising. So, maybe work out your best route upwards beforehand, just in case.

But, what if we wanted to do more than merely ensure our own survival? What if we wanted to actually preserve our cities themselves? Generally speaking, flood defences around the world are severely lacking. Even in a country with infrastructure as advanced as Japan, there’s still very tangible fears that if a vast flood swept over Tokyo, many lives and buildings would be lost. Paris, too, is a major global capital which faces catastrophe if the Seine ever burst its banks. Given the growing threat of climate change, more and more countries are realising that their flood defences might not be up to scratch. Overall, our global prospects seem surprisingly gloomy, at least during the actual event. But, would we be able to recover?

The earth as a whole; probably yes. The vast majority of people, plants and animals currently living on it; probably no. It’d all depend on the scale of the flood. It’s thought that previous periods of global warming and cooling have led to mass extinctions in the past – including the dying out of the Neanderthals, around 40,000 years ago. Whether a ‘great flood’ today would kill off all humankind is impossible to predict, but it’d certainly present us with unprecedented challenges. Landscapes would change, land masses would alter, and the natural world as we know it now would essentially start again, re-evolving in all new directions.

But, the planet, as a Solar System entity, would continue – and, according to some perspectives, it could even thrive. Large-scale change has happened to Earth before, and it has adapted, recovered and reshaped itself. For example, there’s some evidence that the Greenland ice sheet, one of the largest of its kind, almost completely melted away some 400,000 years ago. Clearly, though, the region was able to restore itself, which gives hope for the long-term stability of our world. And, it’s also worth remembering that according to most scientific theories, all life on Earth (including our own) originated in the sea, anyway. So, the land being overcome by water could actually lead to more new species emerging than those that are lost.

So, if Biblical waters did come, the future of humanity would be uncertain – unless we all lived out or days in a global armada of exceptionally well-stocked boats. But, as for our planet, it could more than likely withstand any amount of water thrown at it. And, that’s what would happen if a ‘great flood’ ever occurred on Earth!