What if we had to evacuate from Earth?

In some extreme scenarios, we might have to abandon Earth. Where will we live and why we need to leave?

Reasons to leave

We cannot evacuate Earth because of nothing. The 2 likely scenario is irreversible climate change or asteroid impacts. Let’s talk about how these will happen.

We release a lot of greenhouse gases that warms up Earth every day and therefore, it would be so severe one day that runaway greenhouse effect starts. At that time, Earth would leave the habitable zone corresponding to the greenhouse effect it has. Although it is not 100 celsius, the oceans would boil into vapour so much that it produces a more serious effect. The domino effect goes on until it is as hot as Venus.

Another scenario is asteroid impacts. Although we are studying about diverting space rocks that comes close, it could go wrong or fail. If the asteroid is large, perhaps more than a kilometre wide, it would cause mass extinction on Earth. For survival, we would need to get out of the dangerous planet.

To prepare for the danger, astronomers across the globe are tracking asteroids that can get close to Earth. They are rocks that cross Earth’s orbit or have the potential to do that due to the gravity of the other planets.

Preparations

We sometimes think of evacuating using a single rocket or two, but in fact, it is difficult. A single space mission can take a few years from planning to launching. Then, how about a mission that can take off a good chunk of people to space? Perhaps is takes decades at the top speed, if everyone in the world is in charge to plan and produce the launch vehicle. If the 2880 impact is likely, involving an asteroid 1.1 kilometres wide, we might have to start preparing now for humanity.

Also, climate change is getting more serious now. If someone announces the evacuate plan now, it might be too late because it takes centuries to send all of humanity to space.

Where to move

Next, the concern is ‘where to move’. Currently, the most convenient site is Mars, while exoplanets are light years away. At that time, we might already have the technology to terraform Mars. If we can’t terraform Mars but to evacuate because of climate change, we might evolve as a ‘species in space’.

If we got out of Earth due to asteroid impact, for example, the 2880 impact, we might be able to return to Earth after being in space for about a year or so. We might not need to terraform Mars in a hurry. However, we must accept a lot of economical losses, for instance, from the buildings that are destroyed from impact. Many people would lose their homes, or their hometown becomes uninhabitable.

At that time, perhaps less than a millennium away, it is not a good thing for humanity and the entire civilization needs to start again. Now, be happy that we still have some time to live on Earth, the perfect place for life so far.

Media Credit: NASA’s Eyes, wikipedia.org