Since about 1750, the calculated amount is 1,500,000,000,000metric tonnes (1.5 trillion). And as I understand it, one kilogram of CO2 is the the volume equivalent of a 1mx1mx1m beach ball size
Of course there are absolutely miniscule fluctuations of the amount of CO2 in the atmosphere because, of course, that CO2 is constantly getting taken in by trees and plankton AND getting released from animals and decaying matter. But the due general natural cycle, the system can EASILY remain stable. The cyclical nature allows those miniscule fluctuations to be easily managed.
Now if you look throughout the history of the world, you will find that there were outrageously higher levels of co2 in our atmosphere.... like 15-20x what we see now. And for some, they take that as proof that "we'll be fine" (more on that later). However, it is important to note that the state of the world then was very, very different. Like, incomparably different. How so? Well, vegetation had not yet evolved on terrestrial earth and the only living things were all under water. A planet devoid of a HUGE mechanism for getting rid of CO2 is not an reasonable comparison to today's environment. What's interesting is that plants started to evolve on the surface but it still took millions of years for co2 levels to come CLOSE to what we know today.
But I want to address fluctuations and variations with a cycle. In addition to those high levels, we can find MASSIVE fluctuations in CO2 found in the atmosphere. These fluctuations have different sources but one thing that they tend to have in common (unless it was caused by a catastrophic event like an asteroid or something), is the length of time these changes occurred on. These changes and shifts occurred of tens of millions of years. To demonstrate these very very very LONG term changes, we can see the affect that cycles have in a short term.
Manu Lau is a very famous weather station stuck on top of a mountain in Hawaii far away from development. It has been tracking co2 in the atmosphere for the past few decades...what is interesting is what the co2 increase looks like:
View attachment 347967
Notice how the red line increases and decreases EVEN WHILE the trend line goes up. This is because of a fascinating quirk of our planet. You'd note (if you look at a map) that the VAST majority of our earth's terrestrial landscape is in the northern hemisphere. And of course, tied to that would be that massive amount of vegetation that would be able to take co2 out of the atmosphere and create o2. And so, when the north side of the planet is in summer, the co2 levels are low and, conversely, when the north is in winter there is less vegetable to remove co2. So you see that, even though there is variability, the planet's systems correct themselves: a beautiful balance. At least in a way.
Until you see our trend line. You can see that each year, the top arch of the red line is a TINY bit higher. It's ppm so those changes are quite small. But the important thing to note is that there IS an increase each year.
Still with me? Any questions? Anything you have a problem with?