The principle of conservation gain establishment when one or more than one species in a habitat loose the capacity of sustainability. The reaction of the species affected by different factors includes actions in defence of the same species. That reaction they could cover immigration from a territory to another, self-natural re-balancing of the species involves per natural selection and self-natural re-balancing of the species involves per food-chain. The occurrence, the frequency, the lapses of time of the recovery action is dictated by the habitat conditions.
In the case of the Human species, the possibilities are locked up from the habitat conditions elongated over time. The immigration could happen but partially only and anyway in some point, the coexistence between the members of the community could arrive at a critical point. Always hypothetically thinking, a complete immigration could happen with planet colonisation but I am of the opinion that if we do not sort out the problems that we have right now here on this planet is should pretty useless to try to create another community somewhere else.
There should be a remote possibility of a self-natural re-balancing human species per natural selection but here we can talk about an extreme situation such as the remaining of few thousands human on the planet. This could take few hundred years if everything going on with the actual pace rate. People could die from famine, wars for natural resources, social disorders and so on until just a few of us could survive and reset everything from the beginning. That’s a really bad scenario but could happen and I take that into consideration and as an option.
Lastly but not less important -the self-natural re-balancing human species per food-chain acting as the overconsumption arrestment of no-human species per human life unit-. That’s mean that as the demand for food increase, the number of no- human species will decrease and therefore for the insufficient time of food reproduction, the number of human individuals will reduce on global scale per returning effect of the food-chain. Pretty logic here, no tricks and no ethics… everything will return like before… cost what it cost.
To not sound so drastic and dramatic those examples are few of the worst possible scenario in which the mankind could occur in the future. Those examples are pretty emphasis but scary to me because realistic. In a way or in another those effects will take place gradually on the planet and affect us no matter what. You can contain them however with actions and solution already proposed today from different new emergent companies in the environment sector. You can hold those effects on time, gradually for the future coming, with responsibility and ethics.
We are all unavoidably interconnected each other. You don’t just do this for yourself. However, it’s up to you what do you want to do and what you want to believe.