Thats what will happen if amazon get burn. But thats a big IF so ....
It not suddenly take affect because we have a supply but of course when the time comes we can feel it by the huge number of oxygen given off by trees that's why the population take a lot of oxygen but we have a limited supply so it can cause from people to die, not immediately but their lives become shorter.
even if the whole amazon forest disappeared/burned down the oxygen supply is never the problem because the oxygen produces by amazon forest barely leaves
the forest because the oxygen is almost up by the species, organism, microbes etc.. that are living there(like I said at the first page of this thread). the main problem
we would have is that the trees in amazon forest absorb Co2 in the atmosphere and without the amazon forest the CO2 would remain in the atmosphere
and will contribute to a faster climate change.
How it would never be a problem if you said that it can cause a faster climate change? The food Web can be affected on this case and also you, you can affect also by this even you are not besides amazon forest, not now but soon I think.
The amazon sustains itself and the living things within it. Though the lack of urgency about the fire can make a learned man shake his head, it's hardly going to have a lasting effect on most of us that live away from it. Oxygen mostly comes from those small things in the ocean. I think the title lungs of the earth is romanticized a little too much. Though that doesn't mean it's not as important. A lot of animal lives were lost and that's what breaks my heart more.