Global Atmospheric Nitrogen Depletion

[Randy Korr]

Every school boy knows how important legumes are, because they "fix" nitrogen, that is, they take atmospheric nitrogen (N₂) which is, er, about 80% of our atmosphere, and they turn it into ammonia or nitrates or something that makes good plant fertilizer type nitrogen. If not for those wonderful beans, there wouldn't be any nitrogen available to make proteins or or even DNA, right?

Well, what happens when life goes on for billions and billions of years and all those generations of dinosaurs and ground sloths and Cro Magnons and other biomass gets covered up with ocean sediment? I guess it all turns into petroleum, but that's just a guess.

If all that is going on, and I admit that I am standing on thin ice in this particular area of Science, if all that nitrogen-sucking life keeps it up long enough, are we in danger of losing all the nitrogen in the atmosphere? What happens when 80% of the air is gone? Are our heads going to explode?

R. K.

[BobL]

Well, what happens when life goes on for billions and billions of years and all those generations of dinosaurs and ground sloths and Cro Magnons and other biomass gets covered up with ocean sediment? I guess it all turns into petroleum, but that's just a guess.

Err . . . life has already been going on for about 4 billion years. Before us humans came along the planet had established a kind of a nitrogen cycle. When living things die their remains are on or close to the surface of the earth, other living things and processes recycle the dead materials either directly into living things ie either eat them ( eg scavengers, bugs, fungi etc )or as fertilizer for plants. The amount of once living material trapped in ocean sediment and fossils is tiny compared to the mass of stuff that gets continually recycled.

Also the nitrogen cycle is not responsible for fossil fuel generation - that's the carbon cycles job.

[Barry_White]

We'll just have to breed more chooks. They produce nitrogen every time they c**p.

[Randy Korr]

...nitrogen cycle...

Ahh, and I thought maybe we could save the atmosphere by not eating beans.

R. K.