The Breath of Life.

We need to breathe in order to live. That's rather obvious. We need to breathe air in that mixture of gases that is found on Planet Earth.

So what happens if we continue to foul up this world's atmosphere at a rate greater than the rate at which Nature can clean up? That's obvious too. We run out of breathable air.

Please do not think it will never happen. Air pollution is great in major cities and in not so major cities in the world. The trees, the jungles and forests have been cut down, burnt, removed, whatever. How is the oxygen to be produced in sufficient quantities at sufficiently speedy rates. Industrialisation and development has caused a gigantic increase iin respiratory disorders in the last two centuries and there is no abatement.

We need the air that gives us life. This is the only world we have. The Moon and Mars can't support our lives.