Why Life Would SUCK if Earth Was 2X Bigger

**What If The Earth Was Twice As Big?**

This is what life on an Earth that is twice as big would be like. Let’s start in space. For our thought experiment, we will assume that the Earth is double in every regard—mass, radius, volume, etc. This helps simplify our hypothetical super-Earth scenario and keeps the Earth from collapsing in on itself.

The Earth is also unlikely to be in the same orbit we are in today, not necessarily because of the effect of our increased mass on the sun’s pull, but because of the way we interact with other celestial bodies in our solar system. Much like a party where one person becomes more attractive after a few drinks, the super-Earth would influence the orbits of other celestial bodies, and they would nudge back. Jupiter is believed to have had a significant effect on Earth’s orbit, aiding habitability on our planet. If the Earth was twice as big and harder to influence, we might not be in a position as beneficial to life as we find ourselves in today.

But a super-Earth might pose challenges for any life on Earth, too. The moon is believed to be critical to life on Earth. Its gravitational effect produces predictable tides, which help keep the planet’s climate stable and promote the growth of life. Double the Earth’s gravitational pull, and it’s unlikely we’d have a moon. Much of the would-be moon’s debris would get dragged back down towards the planet’s surface. Over time, the super-Earth would pull even more debris down, potentially robbing the moon of the material it needed to form. We could end up with no moon at all or with a moon much smaller than the one we have today. Life on Earth would have been significantly affected, likely not for the better.

There’s an even bigger problem for the super-Earth than not having a moon. Doubling all parameters of the planet means doubling the amount of material it contains. Specifically, this would mean a doubling of radioactive elements on our planet. However, this wouldn’t mean everyone gets superpowers. Instead, the decay of all those radioactive elements would further heat up our planet’s core and mantle, leading to greatly increased volcanic activity from an abundance of magma beneath the crust.

The Siberian Traps are a massive volcanic rock region stretching across northern Russia. Around 250 million years ago, a massive plume of lava began to rise from the interior of the planet until reaching the crust. This resulted in an explosion of volcanic activity that lasted for about 2 million years and is possibly responsible for the Permian-Triassic mass extinction event. All that volcanism released massive amounts of sulfur dioxide and carbon dioxide into the atmosphere, leading to global warming and the acidification of the oceans. Atmospheric carbon dioxide skyrocketed from an average of 400 parts per million to around 2,500 parts per million—today, we’re sitting at around 420 parts per million. Estimates suggest that ocean temperatures at the equator could have reached as hot as 104 degrees Fahrenheit (40 degrees Celsius).

The Siberian Traps disaster, also known as the Great Dying, led to the extinction of an estimated 81% of all marine animals and 70% of land vertebrates. It’s more difficult to gauge how many invertebrates died off due to the difficulty in finding fossilized remains. With a much hotter core, a super-Earth would likely experience disasters like the Siberian Traps more frequently. Increased volcanic activity would prove difficult for life as we know it. When volcanoes erupt, they can release incredible amounts of greenhouse gases, making our super-Earth much hotter than our normal Earth at the same stage in its evolution. Global temperatures could range from just a few degrees hotter to ten or more, severely impacting how life would have evolved and putting into doubt the ability for intelligent life to arise and prosper.

The atmosphere itself would also make life problematic. With a doubling in gravity, atmospheric pressure would be much greater than we’re used to. The boiling point of water would be higher, and convection currents would be much closer to the ground. This means that clouds would be significantly closer to ground level, and storms would have much more energy. All that extra ocean would allow devastating hurricanes to gain more strength over warm water, making category-five hurricanes the norm rather than the exception.

Another feature of super-Earth that would directly impact the evolution of life would be the terrain itself. With a doubling in gravity, super-Earth would have much smaller mountains and much flatter terrain. This would further compound the wind issue, as anyone from the Great Plains can attest. In fact, super-Earth might be so windy that life might prefer flight over living on land, but that’s just speculation. For fans of majestic views, though, super-Earth would be a disappointment due to a lack of mountains—those that did exist would be much smaller than the ones we know today.

A lack of mountains also means super-Earth might be more arid than normal Earth. Mountains often serve to stop cloud formations, forcing them to condense in one area until they release enough snow or rain. This, in turn, leads to the creation of rivers that feed life all over the planet. With much lower mountains, this natural process may not be as common on super-Earth, leaving much of the planet barren from a lack of rainfall. Life may thrive only in pockets of the planet, with the rest made up of barren grasslands and deserts, where life specialized to survive off little rainfall might exist.

But first, let’s talk about how life would actually evolve on a planet with twice the gravity. Trees, for example, would not grow as tall, as a tree can only grow as tall as it’s economical for them to do so in terms of energy. To keep themselves upright, plants would also grow thicker, more fibrous stems. Flowers would probably still exist—if not be even more common due to an explosion in flying life forms in the denser atmosphere. However, they would bud from tough, thick, fibrous plants, changing the notion of “delicate as a flower.” There’s no room on super-Earth for daintiness—flowers here would be tough and robust. With a greater propensity for airborne life, plants that feast on flying insects would be far more common—though they wouldn’t be limited to insects. Plants would evolve to feed on the greater number of birds too, which might serve as another evolutionary pressure for birds to grow bigger or smarter.

Where do humans fit in this challenging environment? The evolution of humanity is a serious question on super-Earth, at least in any way that resembles what we look like today. With short, squat trees, mammals would find little benefit in becoming arboreal species, making the evolution of monkeys unlikely. Assuming humans existed at all, cities would look very different from today. Rather than building skyscrapers, we would build outwards, dramatically reducing urban density and how many people could be housed in one geographic location. The good news is traffic would be dramatically reduced due to less urban density, but the bad news is that cities would sprawl outwards, paving over vast amounts of wilderness.

You can forget about roller coasters or water parks—the threat of serious injury would be far too great in super-Earth’s increased gravity. Most roller coasters we have today would be unsafe on super-Earth, and rides that involve free falls would be impossible. Cars would need to be built sturdier, adding to the fuel burden that double the gravity would already create. The fuel mileage of the average car would be poor, which could have dramatic effects on how society develops. If cars are only getting a quarter of the mileage they have gotten on our Earth, then super-Earth humans would have to use much more of their planet’s oil reserves faster. Granted, their planet is twice as big, so things might even out, except when it comes to carbon emissions. Super-Earth machines would require far more fuel to operate and produce exponentially more greenhouse emissions than regular Earth. With an already warmer atmosphere due to increased volcanic activity, the super-Earth’s man-made climate crisis could arrive far sooner than our own and be much more severe.

Speed limits would have to be strictly enforced, as crashes would be far deadlier on super-Earth than on regular Earth. Airplanes on super-Earth would not be impossible, just far more difficult to operate. The development of flight would be significantly delayed until the creation of more powerful engines than in our own timeline. However, once aloft, they would have an easier time staying there. The challenge would be landing, which might prove too dangerous to attempt. Aircraft might be limited to operating near large bodies of water, where they can enjoy a more cushioned landing—only when conditions are calm.

The difficulties of living on super-Earth—large insects, heavy gravity, frequent storms, and volcanic activity—might motivate humanity to leave their planet faster than we have. After all, if where you live is challenging, you’re likely to be more motivated to find a way to somewhere more comfortable.

Now go check out “What If The Earth Stopped Spinning,” or click this other video instead!