GIGObuster’s post is a valuable reminder that newspaper accounts are not science. Even the well-intentioned efforts, of which there are many, necessarily simplify the science so that the technicalities don’t glaze eyes. Yes, increasing CO2 is the problem and yes, the ppm count approaching 400 is itself a danger signal. But nuances like proportions of isotopes and their sources are unlikely to be mentioned, even though it’s those tiny details of real science that convince actual scientists.
Neither of these cites answer my question … if we know the mass of fossil fuels humans burn, then we can calculate the rise in CO[sub]2[/sub] concentrations … Chronos claims all the mass is accounted for …
Why not stop with the “just asking questions” schtick, and explain clearly what your issue is?
As GIGO explained, isotope ratios show that the increase is attributable to human sources.
Do you believe that’s not the case? If so, why?
Do you believe that it is the case, but something else is also significant? If so, what?
You have latched onto Chronos’ use of the word “match”, which can mean a lot of things. You seem to think that something does not match something else, and that this is significant. What, exactly, and why?
What Exapno Mapcase said, it does not matter much where that came from, chances are that it was from popular sources, and not wholly accurate, but the point that it should be made though is that… it could be worse:
The worry here is that I have seen reports that the oceans and other natural sinks are not likely to keep up absorbing that much, chances are that the oceans could become **sources **of CO2 and not sinks the longer we wait to control our emissions.
Hijack withdrawn … sorry to bring it up here in GQ …
Even if that doesn’t happen, marine CO2 absorption is already causing a different problem.
I did my own back-of-the-envelope calculations. I looked up how much CO2 comes from burning oil and coal, found the answers 317 kg/barrel for oil and 2000 kg/ton for coal. I looked up how much oil and coal was extracted and burned in the 20th century, found the answers 1 trillion barrels of oil and 120 billion tons of coal.
1 trillion barrels x 317 kg/barrel = 317 trillion kg CO2
120 billion tons of coal x 2000 kg/ton = 240 trillion kg CO2
That adds up to 557 trillion kg of CO2, or 5.57x10^14 kg
The total mass of Earth’s atmosphere is 5.148x10^18 kg
5.57x10^14 / 5.148x10^18 = 1.082x10^-4 , or 108 part per million (ppm).
So, if you burned 1 trillion barrels of oil and 120 billion tons of coal and none of the CO2 got absorbed, you’d expect the CO2 level in the atmosphere to go up by 108 ppm. In fact, it went up by about 90 ppm during the 20th century. One explanation is that only about 1/8th of the CO2 we’ve released got absorbed and the other 7/8th is still up there. IANA Climate Scientist.
Right about what I come up with … maybe where this goes is a good place to put more … I’m thinking biology is taking up a good chunk of the carbon …
EPA web site says 430 kg CO2 per barrel of oil.
We’ve also burnt about 66 trillion cubic meters of natural gas. At 55 kg CO2 / 1000 cubic feet, that’s about 130 trillion kg of CO2. That’s total to date, so call it 100 trillion kg during 20 century.
If we use these numbers we’re up to 770 trillion kg, or about 150 ppm worth.
“Biology” only provides a temporary storage of carbon. It gets absorbed by plants, then released again when the plant dies and decays. It does not remove the carbon from the cycle.
Most of the extra CO2 (that we have put into the atmosphere but isn’t there anymore) was absorbed by the ocean. That’s what’s causing the ocean to acidify.
Biology can provide net sequestration, if the total biomass increases.
Exactly, and that’s where all the fossil fuels we are using came from in the first place, CO[sub]2[/sub] that was sequestered over millions of years.
That’s where all the oxygen we breathe too comes from. The early earth had no O2 and during the time of the dinosaurs the earth’s atmosphere has 40% oxygen compared to 21% today.
And that was a period of interesting transitions.
Suddenly (if these time scales can ever be considered sudden), the atmosphere was polluted with this noxious gas that killed pretty much everything. It also eliminated the nice cozy blanket of CO[sub]2[/sub] that kept temperatures nice and warm, creating a much worse climate catastrophe than the one we are currently looking at, plunging the whole world into ice.
The Oxygen Catastrophe happened long, long before the age of the dinosaurs.
cite?
All the sources I’ve seen say that the highest the oxygen levels ever got was only 35% (not 40) and it only peaked at 35% for a rather short time, just a few million years, before plummeting down to 15%. That was about several million years before dinosaurs, which runs from 247 to 66 Mya. During that time frame, oxygen levels gradually rose from 14% to 31%, spending most of the time in the high twenties.
But did the total biomass increase in the past 200 years?
I think you mean billions of years. And that’s why sequestration by biological processes is negligibly small. Because we’re taking biomass that has accumulated over billions of years and burning them in only hundreds of years.
That a difficult thing to measure even today … most individual life forms are a single cell …
Hundreds of millions of years … much of the coal was laid down during the Carboniferous period … the sea floor is recycled relatively quickly so these fossil fuel deposits are likely on continental plates … so we have to wait at least until the advent of life on land before the carbon is sequestered this way …
Humans are definitely burning these fossil fuel much much quicker than biology can take it up … so this mechanism will do nothing to prevent global warming over these next hundred years … however by then humans may be not be relying on this burning as much and the CO[sub]2[/sub] levels could start to come down again …
Yes you are right. I was misremembering it. The point I was making was that historically earth’s atmosphere always has seen changes - sometimes drastic and fast.
I was talking about what we have already dug up and burned, and I didn’t want to be accused of exaggeration. I don’t think we’ve quite dug up a billion years worth of fossil fuels yet, but I could be wrong on that. Is there actually a good cite that would tell how much of earth’s sequestration history we have undone at this point?