Confused about carbon

bonzodog2

Although an avid recycler and low-energy type of person, there's something that's confused me for a while.
Maybe someone can point out a flaw in my thinking ?
The earth is a closed system as regards matter (e.g. including carbon).
All the fossil fuel carbon was at one time gaseous carbon dioxide, and was converted to cellulose etc by photosynthesis, then the plants died, rotted,got compressed, etc, and eventually got turned into coal, oil, peat, etc.
Other sources of carbon:
calcium carbonate made from the shells of aquatic creatures that died and settled out onto the seabeds of seas that aren't there anymore, eventually forming chalk deposits.
Other mineral ores of a carbonate nature.

Is it therefore true that at some distant point in the past, there was a lot more CO2 in the atmosphere than there is now, and by burning fossil fuels we are just releasing back to the atmosphere CO2 that was there before ?
And consequently, was there a greenhouse gas effect making it a lot hotter at that ancient time ?
I imagine that a lot of greenhouse gases would also have had the effect of reducing the solar energy input (like the 'nuclear winter' effect)

I hope someone can either show me why I'm wrong, or agree with me

bonkey

bonzodog2 wrote: »

Is it therefore true that at some distant point in the past, there was a lot more CO2 in the atmosphere than there is now, and by burning fossil fuels we are just releasing back to the atmosphere CO2 that was there before ?

Yup.

In the early days of the planet, you'd have had a lot of CO2, methane, sulphur dioxide, and other nasty stuff. And it would have been a lot warmer.

Then life came about and it all changed. Slowly. Very slowly.

Since then, CO2 and temp have gone down, and come back up. Its been warmer and colder - globally - than now. Locally....same story, for pretty-much any given locale.

So your reasoning has been bang-on.

Mellor

bonzodog2 wrote: »

Is it therefore true that at some distant point in the past, there was a lot more CO2 in the atmosphere than there is now, and by burning fossil fuels we are just releasing back to the atmosphere CO2 that was there before ?
And consequently, was there a greenhouse gas effect making it a lot hotter at that ancient time ?

There was cetainly more GH gases before life on earth. And it was certainly hotter and colder than todays climate in the past. BUT the problem is not with the temp or the amount of carbon in the atmosphere, its the rate of change. In the past plants and animals either used and gave out carbon dioxide, there would of been some sort of equilibrium or balance depending on the time period and the environment at that time. It would of often changed, but slowly over thousands of years.


We have been burning fossils fuels at our current rate for a very small period of time in a reletive sense. This sudden increase is what is causing the problem as it is unnatural (if the historical changing of carbon levels and temp is to be considered natural)

wazzoraybelle

Back in the carboniferous period there was lots of plant life ( mostly algae) that sucked carbon out of the atmosphere. Bacteria hadn't yet evolved to break down cellulose to release this carbon back into the atmosphere and so it got locked away as oil and coal. This in turn made the planet suitable for the evolution of more sophisticated organisms such as humans.

lucyburn

That is an excellent point OP I've never really thought about that.So by burning the fossil fuels these gases are being released back into the atmosphere.
I know millions of years ago the earth would not have been able to sustain life, and by burning these fossil fuels the world could end up like that again.
That's a really scary thought, I'm so glad i recycle now, and i encourage everybody i know to do the same.