Fossil fuel burning question. Answer isn't global warming!

[bigfatnick]

This is a question that has been rolling around my head for ages.

So we've been burning fossil fuels spectacularly now for more than 250 years, and each time you burn bit of it, you get a load of gasses. These take up much more space than they did as a lump of coal/drop of oil/gob full of gas. So, how much bigger is our atmosphere now than it was 250 years ago. It can't have all been sucked up by trees and seas. They reckon the atmosphere is about 300miles thick, with 80% of it in the 1st 10 miles. I wonder how this has/will change. Will sea level air pressure still equate to 14.7psi in 100 years time?

What do you think science lovers?

[Eric Mc]

I would suggest that the burning of fossil fuel up until 1850 or so was almost completely insignificant). Indeed, I would suggest that significant amounts began to be used only post World War 2.

[FunkyGibbon]

don't forget that combustion takes oxygen out of the atmosphere...

[Tim330]

bigfatnick said:

This is a question that has been rolling around my head for ages.

So we've been burning fossil fuels spectacularly now for more than 250 years, and each time you burn bit of it, you get a load of gasses. These take up much more space than they did as a lump of coal/drop of oil/gob full of gas. So, how much bigger is our atmosphere now than it was 250 years ago. It can't have all been sucked up by trees and seas. They reckon the atmosphere is about 300miles thick, with 80% of it in the 1st 10 miles. I wonder how this has/will change. Will sea level air pressure still equate to 14.7psi in 100 years time?

What do you think science lovers?

Using coal as an example C (oal)+ O2 = CO2
Although you produce 1 molecule of carbon dioxide by burning each atom of carbon, 1 molecule of oxygen is removed from the atmosphere in the process.
1 mole of an ideal gas occupies 22.4 litres so I'd suggest the atmosphere has not increased in size significantly.

For combustion of hydrocarbons (eg methane ,CH4) CH4+ 2 02 = CO2 + 2 H2O
The other product here is water vapour which is in equilibrium in the atmosphere (eg sun light evaporating the oceans) so doubt this makes any difference either.

[Flibble]

CO2 has increased by about 100 ppm (from around 290 ppm to 390 ppm) in the past hundred years or so, it's only a tiny proportion of the atmosphere. Also as Tim says, we're taking oxygen out by burning fossil fuels.

[Einion Yrth]

Flibble said:

Also as Tim says, we're taking oxygen out by burning fossil fuels.

Which is being replaced by photosynthesis and a lot of the carbon is becoming sugars and biomass.

[Simpo Two]

I do wonder how, as the population increases exponentially, the oxygen concentration stays the same. The green plants and the algae must be either growing or working harder, no?

[Getragdogleg]

There are alot of people who fail to realise just how huge the "system" is.

[Flibble]

Simpo Two said:

I do wonder how, as the population increases exponentially, the oxygen concentration stays the same. The green plants and the algae must be either growing or working harder, no?

Because human use of oxygen for breathing is a microscopic fraction of total oxygen use, what we use makes basically no difference.

[southendpier]

Simpo Two said:

I do wonder how, as the population increases exponentially, the oxygen concentration stays the same. The green plants and the algae must be either growing or working harder, no?

Eg Earth's Carboniferous period back in the day.

[Nimby]

Simpo Two said:

I do wonder how, as the population increases exponentially, the oxygen concentration stays the same. The green plants and the algae must be either growing or working harder, no?

The extra CO2 stimulates photosynthesis. The very low concentration of CO2 in the air is one of the main limiting factors for plant growth, and the mechanism all plants use to capture it is surprisingly inefficient (according to New Scientist a few months ago)