What If Earth Were One Continent? | Unveiled

What If Earth Were One Continent?

For about 200 million years the earth has been in pieces. Seven continents - some icy cold, some tropically warm - nurturing a diversity of life on this planet. But what if one day the continents were to reunite? Would they form a new earthly paradise? Would life as we know it survive? And what would happen to humans?

This is Unveiled, and today we’re answering the extraordinary question: What if Earth were one continent?

Today’s what if scenario is more than an idle question. Many scientists agree that the lands of our planet will one day reform into a supercontinent. It’s happening already, right beneath our feet… but we’ve also seen it all before.

The earth once looked very different to what it does today. Instead of seven continents spread around the globe, around 230 million years ago there was just one landmass: Pangaea. The Americas, Africa, Europe, Asia, Oceania, and Antarctica were all then a single mass called a supercontinent. It offered a range of climate conditions and nurtured a profusion of life - including various species of dinosaur.

Then, during the Jurassic period, between 200 and 150 million years ago, Pangaea began to tear itself apart. First into two massive continents and then, over millions of years, into the seven we have now. A new ocean - the Atlantic - opened up as huge chunks of land drifted away from each other. It meant that species that were once neighbours became separated by new seas. And new life evolved as some veteran species perished in this changed world… in the only world that humans have ever known, since it’s here that we became dominant.

The continents haven’t stopped moving, ever since. And, as you watch this video the land beneath all of us is budging slowly (but inevitably) to group together again into a new Pangea. It won’t form tomorrow. Or even in the next one hundred, one thousand, or one million years. But it is happening. Earth’s parts move slower than a human hair grows, meaning the most significant changes won’t complete until more than 100 million years in the future. But these will be eventful millennia, between now and then.

As the tectonic plates that shoulder the earth’s continents move, they grind against (and into) each other - often causing earthquakes. Right now, the plate underneath the Pacific Ocean is slipping beneath the west coast of the United States, for example, in a process call subduction. It’s building up huge amounts of pressure… and, while ‘quakes in the region are already common, an exceptionally large earthquake is invariably predicted to be just around the corner. A monumental event, that some scientists suggest could occur within the next fifty years. Within the next generation. And, considering the tsunami that could also accompany it, it may go down as one of the most destructive natural disasters ever. We can see then, by global, geological events that have already happened in recent history, and by the scale of predicted disasters to come, that although the formation of a supercontinent will take a long time, it’ll also be an extremely violent process.

But say humans can survive that process, and we are still here when the new supercontinent forms… what will it look like? Scientists currently have four main theories about how earth’s puzzle pieces may come together.

The first is déja vu. Known as “Pangaea Proxima”, this future supercontinent looks a lot like the last one… and will come about as the Atlantic Ocean will once again narrow and close. North Africa will again nestle into Europe and the Americas will wrap themselves around both. It’ll mean that Mexico City, should it still exist, could be a day’s drive from Cape Town, and the Libyan capital Tripoli might be little more than a hike from Italy’s Rome.

A second theory posits the creation of a new supercontinent, however, called “Novopangaea”. This time, it’ll come about via a continuation of the same processes that are underway now. The Americas will continue to sail westward as Australia and Antarctica drift northward into Asia. Until such time as they all lock together. Now, the cities of Sydney and Lima, that today have the Pacific Ocean between them, would be but a short drive apart.

Theory number three says that a new ocean will one day open up on Earth, separating India and China from the rest of Eurasia. Meanwhile both the Atlantic and Pacific Oceans close, to create a new supercontinent landmass that scientists call “Aurica”. In this scenario, North and South America would be sandwiched by the European and Asian land masses, and the currently landlocked regions of central Asia would become oceanfront destinations.

A final possibility rests on a theory that new supercontinents usually form at ninety-degree angles to previous ones. In this scenario, it would be the Arctic Ocean that would close, drawing all of the continents together at the top of the world. Canadians would be able to walk to Russia all year round, thanks to this formation which scientists call “Amasia”. A distinctive feature of Amasia, though, is that one of the current continents would not be brought into the fold, with Antarctica continuing to sit where it is at the southern pole.

The appearance and topography of any of these new masses would be very different. Mountain ranges form where landmasses smash into each other, but these sites also dictate how plateaus, valleys, rivers, and lakes take shape. In all four potential supercontinents, the landscapes are unique, and much changed from what we have now. Only one scenario, for example, Pangaea Proxima, predicts the formation of a new inland sea, like the Mediterranean today. As inland seas have proven so important to the development of several of earth’s ancient civilizations, it could then be argued that Pangaea Proxima is the most conducive to human life, as a result.

But, still, there are many more variables. What, for instance, might it be like to travel across a supercontinent? Would there be arid deserts, tropical forests, or fertile marshes? Much depends on where on earth the new supercontinent forms… and NASA scientists have modelled what the climate might be like for two of the four possible scenarios, in particular: Aurica and Amasia. The results differed greatly.

Aurica would be more than three degrees Celsius warmer on average than Amasia. A huge shift by climate standards, caused by Aurica forming near the equator and therefore being exposed to more heat from the sun. Amasia, by contrast, would form closer to the Earth’s northern pole. Temperatures would therefore be lower, but also - thanks to Amasia’s more northerly position - the ocean currents bringing warm air could miss it completely, and instead circle the globe unobstructed by land… leaving Amasia cold, icy, and snowbound throughout winter, spring, summer, and fall. Aurica would be hot and dry inland, with typical equatorial conditions, but it would also be ringed by a beachy paradise - leading some to compare it to present-day Australia. For Amasia, though, the never-ending winter would spread everywhere, leaving just a tiny amount of land along the extreme southern coasts with the potential for farming. While large communities perhaps could survive on Aurica, they’d likely struggle on Amasia.

In general, however, it’s unlikely that anything like the great megacities of today would thrive on any version of a combined continent. In most scenarios, most of our bustling port cities like New York or Shanghai would find themselves landlocked - and perhaps precariously placed in new, very mountainous territories. And, while coastlines have provided some of the most habitable places on earth throughout history, this would be a very different setup - with all coastlines looking outward toward endless ocean.

But perhaps humans and other creatures would struggle for other reasons, too. Some scientists believe that the last time a supercontinent formed, tectonic pressure encouraged a series of massive volcanic eruptions. And these eruptions perhaps poisoned the earth, triggering the most devastating loss of life in our planet’s history: the Permian extinction. Studies have suggested before that supercontinents could be, in some ways, unkind to land animals. So, will we see the same in the future? Will land-dwellers have to deal with similar, hellish conditions? There is evidence, however, that the formation of supercontinents may help to increase the biodiversity of the oceans. So, from a broad life-on-earth perspective, there are some benefits, too.

Of course, we are still imagining a time that’s at least 100 million years in the future. Perhaps 200 million years. And many of the same scientists trying to predict what a new supercontinent would be like might also predict that humans simply won’t be around by then. We may have moved off this world to another, or we may have simply died out. Finally, though, consider that if we were still hanging around, then a supercontinent might even change how we see ourselves. As civilizations evolved on multiple continents over just the past 15,000 years, modern humans have developed a sumptuous diversity of culture, knowledge, and ideas. We have, too, though, developed prejudices, suspicions, and hatreds.

If there were no continents, no seas between us… if we were not Americans or Australians, for example, but all Auricians, Amasians, or Novo Pangaeans… then would we see each other differently? Would we see each other, finally, as the same? And that’s what could happen if the Earth was one continent.