We are not really sure about that, the Scandinavians moaned about the output from British coal fired power stations, but later on it seems that pine needles are innately acidic.
Israeli friends told me about a project that was being considered, huge towers built in the sea designed to evaporate water and provide clouds.
It could work - certainly worth experimenting with.
We don’t know whether the climate is cyclical, whether it has a natural equilibrium or dis-equilibrium.
What we do know is that we have no influence over China and India, so if something is happening, then we had best learn to live with it.
Thanks for the reply, Sentient. I guess I’m not very clear at explaining. Let me try again. No wishful thinking, no miracles, this is simple science.
As human CO2 emissions (from fossil fuels, gas flaring, cement production and landuse) have increased, a curious fact has been noted. This is that not all of the increase has ended up in the atmosphere.
By 1950, for example, we had released some 131 gigatonnes (Gt) of carbon (C) into the atmosphere as CO2. However, measurements of the CO2 in the atmosphere show that only 56 tonnes of it remained in the air. The rest had been sequestered by the planet (following figures in gigatonnes of C).
From 1951 to 1960, we released 34 Gt, of which 22 Gt was sequestered.
From 1961 to 1970, we released 47 Gt, of which 29 Gt was sequestered.
From 1971 to 1980, we released 63 Gt, of which 36 Gt was sequestered.
From 1981 to 1990, we released 76 Gt, of which 43 Gt was sequestered.
From 1991 to 2000, we released 86 Gt, of which 53 Gt was sequestered.
As I mentioned, this is a typical response of a system to disturbance, called an “exponential decay”. Consider the earth, and imagine that there are no disturbances. Then, one year, we add 30 Gtonnes of C to the atmosphere. Will it still be there in 1000 years? No, the amount in the air will gradually be reduced, year after year, until the original proportion is restored.
But the reduction will not be linear. It, like most disturbances of this kind, follows an “exponential decay”. This means that every year, a certain percentage of what remains in the air will be sequestered. For CO2 in the atmosphere, this is about 3%. So the first year the earth will sequester 30 Gt x 3%, or about 0.9 Gt. The next year, it will sequester 3% of the remainder, 29.1 Gt x 3%, about 0.87 Gt. Each year, the amount sequestered will be smaller.
If we continue to add more than is being sequestered, the airborne amount increases. And because about 3% of the airborne amount is sequestered, the total amount being sequestered rises as well. Note that by the 1970s, the airborne amount had become large enough that more was sequestered in the 1970s than was released in the 1950s.
This is why I said that if emissions do not increase, the airborne amount will level off. The amount in the air at that time will be such that 3% of the airborne amount (the amount sequestered) will exactly equal our emissions. This will be on the order of 425 ppmv.
You ask “what is the mechanism”? It is the same mechanisms which have been operating since forever. One of the things about chemical reactions is that when you increase the concentration of one of the reagents, it drives the reaction in the other direction. Google “Le Chatelier’s Principle” for further information.
Sure, I’d be glad to take a bet on the question. Nothing makes me happier than a bet on a sure thing. My bet is that you’ll agree with me now that sequestration is increasing, no need to wait five years. I have put an excel spreadsheet with all of the data here so anyone can check my figures. Take a look at the data and you can tell me if sequestration is increasing as emissions have increased. If it is, I win the bet. If not, let me know what is wrong. I have included references to the data. Get back to me on this one, loser has to apologize to the other guy. :smack:
w.
My “miracle mechanism” is exponential decay, and has been operating all along. See my previous post.
In any case, average increase last ten years, 1.9 ppmv, average last five years, 2.1 ppmv, call it 2 ppmv. 93 years left in this century, current CO2 is 380 ppmv plus 2 * 93 = 566 ppmv …
w.
Dang, glad to hear it, I knew I’d set a record some day …
You cite an article and say that it’s real scientists … thank you for that citation, I hadn’t seen the article. Here’s some quotes from that article.
OK, we have two scientists disagreeing about the tides. You get to choose which one to believe. I’ve had a reasonable amount of discussion with John Hunter about this very subject. In any case, John goes on:
In other words, he doesn’t see enough sea level rise to explain what’s going on. It is certain that the sea water is intruding into the fresh-water lens under the island … but sea level rise is not enough to cause that either. Since this is mainly happening on Fongafale, the main atoll, the most likely reason is the giant paved airstrip that they put in and have recently extended, which caps the atoll and prevents the rain from replenishing the fresh water lens.
The article goes on to say:
Nothing unusual in the sea level changes … the article continues:
I know Carol, her project is interesting. You seem to think that the Tuvaluans are all wrought up about this issue … she disagrees.
The article also says (emphasis mine):
Do we see a pattern here? People destroying the reefs, changing the structure of the island with fill and rubble, and then thinking that sea level rise is flooding their island?
(Webb, by the way, works for SOPAC, the organization whose report you trashed for being 11 years old … as if the conclusion that reef destruction and coral mining were the cause of Tuvalu’s problems had a “use-by” date.)
Finally, you had said:
I found the article most interesting because it goes on to say:
It’s interesting to me because I’m not just an “anonymous internet user” as you claim. I am Willis Eschenbach, I have published on this topic, I know the players, I’ve seen the atolls, and I’m one of the scientists quoted in your citation … so at this point, you are the anonymous internet user. Their description of my position was good, except that they misrepresent my conclusion. They say
In fact, I did not say that sea level rise in Tuvalu is an “illusion”, that’s nonsense, there’s sea level rise everywhere. I concluded that a) there was no increase in sea level rise over the historical levels, as is shown by the other quotes above, and b) that the damage being done in Tuvalu is from erosion due to human-created changes in the reefs and islands, just as Webb says above. I made no argument about whether the Tuvalu situation was evidence for climate change, there’s no “evidence” there for either side.
I also recommended the “no-regrets” types of actions that Webb has proposed, both in my article and to the US Ambassador to Tuvalu, who passed it on to the Tuvaluan Government.
Kinda humorous, though … you go out to find an article to support your side, and you end up with an article quoting (and also mis-quoting) me … go figure.
w.
Ah, perhaps I wasn’t clear enough with my question - of course I believe that if we reduced our emission rate to the annual sequestration rate tomorrow, the CO2 concentration will level off at some point in the future. My question was, more specifically, will the sequestration rate increase such that the annual increase in CO2 concentration will start to fall?
No, let’s stick to the next five years’ data, and I’ll clarify the bet: The current rate of increase for CO2 ppm is over 2 ppm per year.[ul][li]I bet that it will continue to increase at, on average, over 2 ppm per year for each of the next five years. [/li][li]If it starts to fall below 2 ppm per year (or 2.1 ppm per year, or another level to be agreed upon – you can name your threshold since we might disagree on precisely what the current rate of increase is), you win the bet. [/li][li]If we see an increase of 3 or more ppm per year, I win big.[/li][li] Loser to pay for a white T-Shirt printed with a message chosen by the winner in 3 inch bold black letters, to be worn in a busy public place, and a photograph of this to be posted on this message board.[/ul]Deal or no deal?[/li]
And could you address my points about your incredibly optimistic choice of sensitivity and utter absence of time lags and positive feedback in your predictions given how little you say we know about climatology?
Yes, I’m afraid it shows.
Sentient, thanks for the post. This all started with your offer to bet on whether the amount of CO2 sequestered each year was rising, a claim you derided as being “faith-based”
I said, sure, we can settle it right now. I provided the data to do so.
You reply that no, whoa, wait a minute, you don’t really want to bet on whether the amount of CO2 sequestered will rise as you clearly stated. You want to bet on whether the rate of atmospheric CO2 growth will increase above the current levels …
While that is an interesting question, it is not what you offered to bet about. Does this mean that you’ve seen the light, that my claim that sequestration has been increasing is not “faith-based” but is hard scientific fact, that increasing sequestration is not a “miracle” as you claim but is actually happening?
Finally, you say:
Sorry I missed those, and the thread is too long to guess which points you are referring to. Please restate them, I’d be more than happy to discuss them.
w.
PS - you say:
That is not what I said. I said that if we freeze our emissions rates at present day levels, because of increasing sequestration, the CO2 concentration will level off at some point in the future.
On the other hand, if we reduce our emission rates to the annual sequestration rate tomorrow as you say, the CO2 concentration will level off immediately. Since by definition everything we are emitting is being sequestered, how could it do otherwise?
intention: Your simple model invoking exponential decay and Le Chatelier’s Principle is way too simplistic. In the real world, there are many different processes with different decay rates that govern the uptake of CO2. I am not all that knowledgeable on carbon cycle modeling but the impression that I get is that there are many potential positive feedbacks that can come into play and do not bode well for the future. Here is some discussion of future changes in ocean CO2 uptake. And, here is some discussion of constraints on terrestrial CO2 uptake.
I am sure that the scientists who work in the field are familiar with Le Chatelier’s Principle and exponential decay and yet I am also pretty sure that their conclusions don’t generally agree with yours. (Feel free to demonstrate otherwise.) It is thus incumbent on you to explain why you are right and they are wrong.
Along the lines of my last post, here is some information from the summary of the IPCC chapter on the carbon cycle:
That seems to paint a very different picture than your simple model.
Sure, be glad to, but since their conclusions do agree with mine, I don’t have to show they are wrong. As luck would have it, someone on a list I read cited a study just today that is directly to the point, by Mark Jacobson of Stanford, the only climate modeler worth listening to. This paper is not about models, however, it is about the exponential decay of CO2 in the atmosphere. Note in particular Figure 2, which shows exactly what I said.
This was that if we freeze our emissions at the current rate, the atmospheric concentration will not rise indefinitely, but will level out well below 600 ppmv. (I had calculated that it would level out around 420 ppmv, Jacobson says 440 ppmv.)
Note that there is no discussion in the paper about the fact of the exponential decay, that’s accepted science and not questioned, the discussion is about the speed of the decay.
You derided this statement as “faith-based”, called it “miraculous”, and generally ridiculed me for making the claim … now that I have shown that it is accepted science, could you back off a bit on the abuse, and perhaps consider that your own opinions might not be as scientific as you think?
w.
[QUOTE=jshore]
Along the lines of my last post, here is some information from the summary of the IPCC chapter on the carbon cycle:
[quote]
There is sufficient uptake capacity in the ocean to incorporate 70 to 80% of foreseeable anthropogenic CO2 emissions to the atmosphere, this process takes centuries due to the rate of ocean mixing. As a result, even several centuries after emissions occurred, about a quarter of the increase in concentration caused by these emissions is still present in the atmosphere. CO2 stabilisation at 450, 650 or 1,000 ppm would require global anthropogenic CO2 emissions to drop below 1990 levels, within a few decades, about a century, or about two centuries respectively, and continue to steadily decrease thereafter. Stabilisation requires that net anthropogenic CO2 emissions ultimately decline to the level of persistent natural land and ocean sinks, which are expected to be small (<0.2 PgC/yr).
The problem with this is that the IPCC is using a very long residence time, up to 200 years, while the data gives a very different answer. See the Jacobson paper cited just above for a discussion of this issue.
Also, stabilization does not require that emissions decline to 0 as they claim. Think about it and you’ll see why.
Thanks,
w.
The earth will be just fine. It will shrug us off like a leisure suit. Perhaps in the earth’s future, it will have some sort of nostalgia television show. Maybe even a whole series, with funny clips of remembrances from something very much like Mo Rocca.
“Hey, Remember the Humans!”
“I Loved the Dinosaurs!”
Maybe it will have insults for other planets, like “Hey Saturn, the Time of the Humans called. It wants its hairstyle back!”
It’s not arrogance to think that we can destroy ourselves, is it?
It is not entirely clear to me that just because this is the assumption used in this paper, it means that it is accepted science that the decay can be approximated by a simple exponential. In fact, you want me to believe this one paper and then to ignore what the IPCC says, which represents a summary of the entire peer-reviewed literature. (Admittedly, the IPCC report is now a bit dated…So, it will be interesting to read the 4th assessment when it is released next month.)
Anyway, I will try to look into this more when I have the time. I have never given much focus to the carbon cycle stuff.
Actually, you are attributing statements to me that were made by another poster. What I said is that you model is too simplistic as there are many different processes with different decay rates that govern the uptake of CO2. This is why the actual decay of CO2 levels back to their pre-industrial values (once we essentially cease our emissions) is not expected to be a simple exponential, but will have a long tail, as noted in IPCC report.
intention, I apologise if my original offer of a bet wasn’t clear, which is why I clarified it. Just to be clear, are you refusing to bet on whether or not the annual CO2 concentration increase will fall or not? Here, I’ll point out a crucial phrase you seem to be blind to:
I wasn’t disputing your figures about more CO2 being sequestered every year, but about whether that would ever start to make a difference to the number which actually matters: the annual CO2 concentration increase. That’s why I clearly referred to what you miracle proposes:
I hope we’re now both as clear as we can be about what the bet is.
Again, just for clarification: Deal or no deal?
You must admit, your prediction of sensitivity is way, way up in the most optimistic clouds of cuckoo land. How do you square this with your repetition of just how clueless we are at predicting what will happen, since said uncertainty must surely admit the possibility of worse case scenarios?
But Le Chatelier’s principle is for a reaction in equilibrium and, yet again, we just don’t know whether the climate can be modelled so. You chided me for applying simple physics to a complex system and compared aluminium and a human body. Here you are doing the every same! Yes, add ethanol to a simple chemical reaction and you’ll see an “opposition” to its increase in concentration. But keep giving uniform shots of whiskey to a human being and the consequences are altogether different. (And if we know so little about climatology, we simply can’t say where the saturation point is, if anywhere. That’s why I wanted to explore the actual mechanisms of CO2 sequestration, analogous to the statistically simple collisions in a beaker of solution).
No, if we stopped emitting literally any more CO2 tomorrow, there would still be all those excess Gigatonnes from last year, and they would then begin to be sequestered at such and such a percentage per year. This is why I asked you why you seem to assume zero time lags in terms of release and effect. Those excess 86-53=33 Gt won’t disappear overnight, whatever we do tomorrow.
intention, FRDE, Leaffan and others, I have to thank you.
It takes a big man to admit this, but … you ready?
I have changed my mind.
By the way, a good general discussion regarding the fate of the CO2 that we release into the atmosphere is this guest commentary by David Archer on the RealClimate website. [If you are allergic to RealClimate, then you can start with the reference section and go directly to the peer-reviewed literature it cites. 
] It explains the mechanistic issues involved and the timescales associated with different processes.
So far we’ve covered three cases: Netherlands, Maldives, Tuvalu. In all three cases we’ve seen cites that waters are rising and some land has already been abandoned. Further in all three cases we’ve seen that this is a combination of global warming and local factors such as coral reef destruction. Now, intention, you keep wanting to emphasize that the local factors exist. Yes, I’ve never denied that they exist, but the point is that climate change is also a factor. Further, given the accelerating melting in Greenland and Antarctica, the rate of flooding resulting from climate change is guaranteed to accelerate in the near future.
This discussion began when Leaffan asserted that global warming was a myth cooked up by a secret conspiracy of Marxists. I responded that the human race is currently abandoning some land because of rising sea levels. Pointing out that some of the flooding comes from other factors doesn’t change my argument. As long as some of the flooding comes from rising sea levels due to melting ice sheets, it’s useless to pretend that global warming isn’t happening.
Of course, since Leaffan has run with his tail between his legs, the point is unnecessary.
Hogwash. Your original bet offer was perfectly clear. You said “If the amount of CO2 sequestered shows an average increase over the next five years, in line with your predicted miracle, I will lose the bet.”
Let me spell it out for you. If the amount of CO2 sequestered goes up, you lose the bet. Is it clear now?
In fact, you are not willing to put your money where your mouth was. I said sure, I’ll take that bet, and now, you want to pretend it was not clear. CO2 sequestered goes up, you lose, it’s perfectly clear … but now that I’ve sent you the data and the references, ooops, you realized that CO2 sequestration has been increasing for the last 150 years … so now you want to whine about how you weren’t clear.
Man up. Admit you were wrong, admit that the increasing sequestration has always made a difference in how much remains in the air. How could it not?
w.
PS - you say “You admit that 3 gigatonnes of CO2 per year are not being absorbed, but pull from your hat the assumption that this number will start to decrease (presumably soon, ie. in the next decade or so?).” Please provide me with a citation, I don’t recall ever saying anything of that nature.
PPS - It seems that now you want to bet on something else, but unlike your previous bet offer, whatever you want to bet on isn’t clear at all. There’s no timeframe, there’s no specification of what’s being measured, there’s no baseline. Unlike your last bet offer, which was perfectly clear (if on average CO2 sequestration increases over the next five years, you lose), this one contains no specifics at all.
jshore: that commentary seems to ignore what would happen if deforestation stopped tomorrow and reforestation of large areas were to take place. Wouldn’t that suck a bunch of carbon out of the atmosphere, or am I mistaken in thinking this?
Even taking this as a given, that’s one hell of a condition that you set. Even with radical policies in place, I doubt that emissions will cease to increase any time soon. Though I’m provisionally convinced by your arguments, they seem rather irrelevant, since (from the data you provide) carbon emissions are increasing. It’s kind of pointless to talk about some equilibrium climate state with constant emissions, when they continue to increase at an accelerating rate.