It would
take a very long time for all the oxygen already in the atmosphere to be used
up by respiration of the life on earth even if the generation of oxygen stopped
immediately and completely tomorrow.
I could not find data for the total respiration rate of life on earth, but since respiration is essentially the burning (with oxygen) of the food (fuel) that life consumes, we could instead look at the question of whether we would run out of oxygen if we were to burn all of the biomass on earth. After all, when one organism eats another organism as food, it will eventually "burn" the food organism - so by considering the burning of all organisms we are considering the case where life eats all other life on earth.
Now according to Wikipedia the earth's total biomas is 560 billion tonnes. That total biomass is only about 1/45,000th of the mass of the atmospheric oxygen of the earth . So it is clear that burning all the biomass of the earth would only decrease atmospheric oxygen content by a tiny amount.
That is why short term fluctuations in the rate of oxygen generation in photosynthesis compared to the short term rate of oxygen consumption in respiration does not matter. The huge buffer of oxygen in the atmosphere totally damps out these short term fluctuations - it is only the long term balance of generation and consumption of oxygen which will make any change significant to the total oxygen content of the atmosphere. By long term I mean millions to billions of years! Any short term change in the atmosphere oxygen percentage would be insignificant compared to the ecological disaster of photosynthesis significantly decreasing on earth. The disaster would be in the food availability, not in oxygen availability
So don't worry about oxygen depletion, but do worry about possible ecological disasters that would affect life on earth. The disaster will be ecological, not due to a lack of oxygen.
ALVARO EGIDO
I could not find data for the total respiration rate of life on earth, but since respiration is essentially the burning (with oxygen) of the food (fuel) that life consumes, we could instead look at the question of whether we would run out of oxygen if we were to burn all of the biomass on earth. After all, when one organism eats another organism as food, it will eventually "burn" the food organism - so by considering the burning of all organisms we are considering the case where life eats all other life on earth.
Now according to Wikipedia the earth's total biomas is 560 billion tonnes. That total biomass is only about 1/45,000th of the mass of the atmospheric oxygen of the earth . So it is clear that burning all the biomass of the earth would only decrease atmospheric oxygen content by a tiny amount.
That is why short term fluctuations in the rate of oxygen generation in photosynthesis compared to the short term rate of oxygen consumption in respiration does not matter. The huge buffer of oxygen in the atmosphere totally damps out these short term fluctuations - it is only the long term balance of generation and consumption of oxygen which will make any change significant to the total oxygen content of the atmosphere. By long term I mean millions to billions of years! Any short term change in the atmosphere oxygen percentage would be insignificant compared to the ecological disaster of photosynthesis significantly decreasing on earth. The disaster would be in the food availability, not in oxygen availability
So don't worry about oxygen depletion, but do worry about possible ecological disasters that would affect life on earth. The disaster will be ecological, not due to a lack of oxygen.
ALVARO EGIDO
No comments:
Post a Comment