>>13866788i love this question
1. Carbon dioxide has a provable greenhouse effect in the atmosphere
2. Now there are many carbon cycles on the planet some of them produce far more than carbon than humans ever could.
These cycles are briefly:
Decomposing life
Growing life
Chemical weathering
the oceans dissolving carbon and outgassing it
Volcanism
These have been in near balance for much of the holocene (in fact the balance was slightly negative so without the forthcoming human intervention we would have slid back into an ice age)
But as you can guess humans started producing carbon dioxide. Just enough to tip the carbon flux into the positive and beyond. Imagine a scenario where two swimming pools are pumping water between one another in a loop, turning on a tap to this system will eventually lead to overflow.
3. But how can we definitively tell that our carbon is to blame?
The answer is found in the carbon atoms themselves.
While floating around in the atmosphere carbon 13 (the stable isotope) has a small chance of being hit by cosmic rays and becoming carbon 14
However if you bury carbon that has carbon 14 in it it will eventually decay away and after a million years the carbon 14 will be extremely rare.
by analyzing the isotopes of carbon in the carbon dioxide in the atmosphere we find about a 33% increase in carbon 13 compared with the normal ratios that should be expected from random cosmic ray bombardment. 33% is almost the exact amount that carbon dioxide has increased since humans have started the industrial scale use of fossil fuels.
