Why live in a sustainable way? Good question! The most obvious explanation is to not ruin our environment: to not destroy all the trees, make fish go extinct, etc. Let’s keep the environment as it is with the current systems and species. Let’s preserve the environment and not make a negative impact on the planet. All these things I think are great and any environmentalist would agree. And this is the reason provided by most people that are currently promoting and pushing for change. However, unless you truly like to go hiking and see nature beyond human life, or if you like to eat food that is harvested from the wild, then you might not care about saving it. To just to protect the environment requires you to make the actions of living sustainably out of the goodness of your heart, for the most part.
A more selfish reason that could convince more people is this: if we change our planet enough, we may cause our own extinction. If, for example, we pump enough CO2 into the atmosphere that it changes the climate too quickly, then many species won’t be able to adapt quickly enough, and we may put our own human existence into jeopardy. Humans have evolved into our current environment, and our ability to exist depends on the planet to be in a particular state for us to have access to vital resources, like water and food. Of course, the world is always changing and evolving, and it will continue to do so. For example, the atmosphere didn’t always have this level of oxygen, and the overall temperature in the Ice Age was much colder. But if it changes too fast, we may not be able to keep up. So really, we must adopt a more sustainable way of living to save our own species, not out of the goodness of our hearts. If we change the environment to a point that makes humans go extinct, the planet will still be here, and I’m sure some life will evolve and keep on living without us. History teaches us that this is common. There have been a few mass extinctions on this planet, and each time the planet changes and life evolves, but we have to be smart enough to at least not cause our own extinction. We may not be able to prevent natural disasters, or a comet hitting the earth, but we can do other things to prevent our demise.
The choices we make today might not affect your lifetime, but it will affect your children, and their children, so the only person that should not care about living sustainably is the one who does not want to have children and does not care about humanity’s continued existence. I cannot necessarily judge a person who thinks this way. My only comment is that humans are pretty cool creatures, and even though they can be selfish and do harm sometimes, many of us do beautiful things. If you have a negative outlook on the human race, try to think of our potential and what the future humans could be like, and not simply what they are now..
However, despite how well we take care of the planet, the unfortunate reality is that our Sun–which all life depends on–is going to burn out in the distant future. The Sun is this planet’s primary source of energy, and we need some form of energy to survive. Plants grow from the Sun’s energy and we eat the plants; the Sun’s energy evaporates water and makes clouds to create rain… even wind is made from the Sun due to temperature fluctuations in the rotating planet and warm air interacting with cool air. Without the Sun, I think it is obvious we are toast. All stars, including our Sun, have a life span, and will eventually die (just like all other things), so there is a deadline of when this planet will not be livable.
So what is the point, then, to maintain our planet in a condition for us to live, when in the end, all life on earth will end when the Sun enters the last stages of its life? The first reason is because life itself is so beautiful and awesome, so let’s keep enjoying it for as long as possible and in the best conditions possible. And let’s pass this gift of existence to our kids, and their kids. The other reason is to buy us enough time to learn about the systems of the planet and life and to progress enough in science and technology to be able to leave this planet in a spaceship and move to another star. There are many stars out there in a different phase in their life cycle, so the solar energy we get from the Sun is available elsewhere. We can use this energy to create an ecosystem on a spaceship, then we can travel to another star, and maybe even a new planet. Unfortunately, with modern science, we do not know how to do this yet, and maybe we never will, but we can try! We need time to study, advance science and technology and figure it out. Every day we are gaining collective knowledge very fast and making a lot of progress.
Bringing this all full circle: one of the first and most important steps to building a spaceship that is self-sustaining is to understand how can we live on this planet sustainably. We need to learn how to live by recycling resources; to live in a circular and regenerative way. We must master this so we can recreate this system on a spaceship and move to another star. Even Mars, which some think could be our next home, is not a viable long-term option since its main source of energy is also our Sun. No matter where we go, learning how to live in a sustainable way and harnessing and making the best use of extrasolar energy is they key to mankind’s continued survival.
Maybe you think humans only belong on planet Earth and should die with this planet. Yes, we were born out of this Earth, and of course this is our ancestral home. We only exist the way we are because of the things that have happened in the past and the conditions leading to our existence. But all life forms seek to continue their existence wherever they can. They try to live in all conditions and test their boundaries. There may even be some life on our planet that has traveled from elsewhere. Seeds from plants drift in the wind and land all over in an attempt to simply exist. I think it is the nature of all living things to try to continue to exist and evolve. Therefore, I think our attempt to leave our dying sun to attempt to exist is natural. We don’t know what the future holds, but we can hope for the best and make our best effort.