Will we ever run out of air?
Air is stuck to the planet by gravity, it won't leave. Two things are adding to the air all the time too, the planet is always releasing gasses from volcanoes and volcanic vents, and there are some meteors that are mostly ice that evaporate when they hit tie air.
Probably not, at least in our lifetime. Global heating may cause plants to die, and then we could run out oxygen, but we just don't know yet.
And don't forget the loss of Rain Forests..They generate a lot of oxygen. As they are destroyed, we will be choking ourselves for oxygen.
As Ken pointed out volcanoes replenish the atmosphere. There is another import effect which protects the atmoshere: The Earth's magnetic field. The magnetic field deflects high energy charged particles from the Sun. Without this field the atmosphere would be slowly stripped away by the solar wind.
The Earth's magnetic field is generated in the liquid outer core of the Earth. Some time in the future the Earth's interior will have cooled down to such an extent that there will be much less volcanic activity and also the outer core will have solidified. From then on the Earth will start to lose its atmosphere.
We know that this happened on Mars a few billion years ago.
In terms of running out of air, it is highly unlikely that we will completely run out of air in our lifetime. The Earth's atmosphere is held in place by gravity, so it won't simply disappear into space. In fact, there are natural processes that constantly add gases to the atmosphere, such as volcanic activity and the evaporation of ice from meteors.
However, there are factors that can impact the availability of oxygen in the air, such as global heating and the destruction of rainforests. Global heating could potentially cause plant die-offs, which would reduce the amount of oxygen produced through photosynthesis. Additionally, the loss of rainforests, which are major oxygen generators, would also have an impact on our oxygen supply.
It's important to note that the Earth's magnetic field also plays a crucial role in protecting the atmosphere. The magnetic field deflects high-energy charged particles from the Sun, preventing them from stripping away the atmosphere. However, over a long period of time, as the Earth's interior cools and volcanic activity decreases, the magnetic field could weaken, leading to the gradual loss of the atmosphere, similar to what happened on Mars billions of years ago.
So while a complete depletion of air is not likely in the immediate future, it's important to take action to mitigate factors that can impact oxygen supply and protect the environment for future generations.