Since 1970, Earth Day has been celebrated every April 22 , a social movement that fights to preserve our planet and its natural environment, to guarantee that it will continue to be present and in good condition for future generations. This ranges from reducing greenhouse gas emissions to combat the global warming that we are causing, to reducing the amount of waste (biodegradable or not) that we end up throwing into our rivers, forests, seas and oceans.
Our planet is a large ecosystem and our actions can have serious consequences on it. In addition, preserving the natural environment brings benefits to almost any field of human activity , including the economic field. Countless processes maintain a beautiful balance that makes this planet the only one capable of supporting life as we know it.
However, in science fiction movies and in the fantasies of technological optimists, the following situation is sometimes shown: a planet Earth devastated by human actions and unable to sustain our society any longer and a new world discovered and to be explored where humanity could enjoy a second chance . Many times this paradisiacal potential is attributed to Mars. Other times it corresponds to exoplanets of which we barely know more than their mass, size and the distance at which they orbit their star.
In any case, these fantasies are just that, fantasies. The reality is that, spoiler, no planet is capable of giving us shelter better than Earth and most likely no planet will ever be able to do so, no matter how advanced our technology is. This does not mean that we cannot, in the future, colonize other worlds and even build something resembling a society on them . What it means is that none of these planets could replace the Earth, no matter how much we pollute and spoil it. Let’s see why.
Human beings and all living beings with whom we share the Earth have evolved over more than four billion years to inhabit this particular rock , which orbits this particular star and at the particular distance at which it does so. The conditions of the Earth have not remained constant throughout all this time, but within their variability they have never resembled the conditions that we currently find in any of the objects in the solar system.
The Earth has a very specific gravity, it receives a specific amount of solar energy , it has an atmosphere with a very specific composition and its climate varies within certain parameters of temperature, humidity , etc., with a certain amplitude, but also concrete. Furthermore, on Earth we have large amounts of easily accessible liquid water , we have a soil in which we can plant, without further consideration, any plant that we need to consume and an infinity of conditions that make our life possible on it.
Imagine that you move to a new house. This house is located on another continent , in a country without infrastructure where nobody speaks your language and they are also unfriendly people who will never lend themselves to help you. Of course when I said house I meant that you are moving to an empty piece of land on top of a mountain , where the soil is toxic , where it is always -50ºC and where the air is unbreathable (if you have the luxury of having air). I’ll give you a helicopter so you can get your gear there. Of course you will not only need to move your furniture and belongings, but also the necessary machinery to build your house , to generate enough energy to make it habitable and also a way to generate new supplies or store large quantities of them until you get it.
Therefore, even if we increase the average temperature of the Earth by 10ºC or even if a nuclear apocalypse causes a mass extinction or any other environmental catastrophe that we can imagine, the Earth will continue to retain most of the factors that make it habitable and will undoubtedly take them into account. larger than any other celestial body.
From this fact arise the slogans that remind us that “there is no planet B” . There is no second option, a reserve or a backup. Explore the solar system , of course, create self-sufficient bases on other planets, with a lot of effort and within decades or centuries but also. But moving to another planet. Completely abandoning Earth and bringing all of humanity to inhabit another tiny rock orbiting the Sun or another star, certainly not .
Not even if we found an exoplanet of the same size and mass as Earth, orbiting a star identical to the Sun and at the same distance, with an equally dense atmosphere and with liquid water on its surface, could we consider it. Our oxygen levels remain constant thanks to the fact that terrestrial life (mainly photosynthetic plants and cyanobacteria) constantly replenishes it. Without them it would disappear in millions of years. If somehow that planet had life capable of maintaining comparable levels of oxygen in its atmosphere, the very contact with such advanced biology could be deadly , to terrestrial organisms, to aliens, or even to both. All this, of course, without counting on the logistical nightmare of moving an entire civilization to a planet located light years away.
REFERENCES:
M. Neira, 2015, Our lives depend on a healthy, OMS, planethttps://apps.who.int/mediacentre/commentaries/healthy-planet/en/index.html
