Discussion > So where are Salby and Darwall wrong .... precisely?
The True Believers are intensely scared of Salby.
He is an atmospheric physicist with a heavyweight track record of research accomplishment over decades. On climate change, he has looked at the data and his analysis shows a whole collection of things are not as the True Believers believe.
He has found:
- Increased global temperature results in increased atmospheric CO₂.
- Regions where CO₂ is above the global average concentration are regions where there is little or no industry and little human population.
- If the lowpass filtering effect of proxy temperature records is allowed for when they are compared with instrumental records, recent temperature changes are in no way exceptional.
And so on.
Martin A
Well worth viewing if you have not already seen it.
Martin A
Mike,
Okay, let's clarify that we're talking about what is causing the long-term rise in atmospheric CO2 that started around the mid 1800s, which Salby appears to be suggesting is mostly natural. i.e., the article says
Rather than increased levels of CO2 in the atmosphere triggering global temperatures to rise, rising global temperatures come first—and account for the great majority of changes in net emissions of CO2, with changes in soil-moisture conditions explaining most of the rest.
My assertion is that the rise is almost all (maybe even just "all") anthropogenic and that that is trivial to show. Are you suggesting that the rise (about 120ppm since the mid 1800s) could be mostly natural and driven by mostly by the rise in temperature?
And Then There's Physics
I'm not suggesting anything. You (and others) vilify Salby without ever providing anything remotely approaching evidence that he is wrong. We are left with a series of "well of course everybody knows that" as the justification for your arguments.
In this reply you admit that you are "asserting" that the rise is all anthropogenic. Even if it is it doesn't follow that it is causing a rise in temperature since:
1. the 120ppm you claim (and which has also been disputed - some studies are less certain that the level was 280ppm "since forever" and suddenly started to climb) began in the mid-1800s and yet only since 1975 has it been responsible for increased global temperatures, according to the climate science fraternity, and
2. data from the last 15 years show that CO2 has continued to increase while temperatures have failed to oblige.
If I remember correctly it was in 1997 (or thereabouts) that ice-core data upset the IPCC apple cart by proving that CO2 increases lagged temperature increases by ~800 years so that circle needs to be squared as well. The favourite argument appears to be "well, yes, it does to start with, but after that ..." Taken to its logical conclusion that argument suggests that the earth should have burned up several millennia ago.
Mike Jackson
Are you suggesting that the rise (about 120ppm since the mid 1800s) could be mostly natural and driven by mostly by the rise in temperature?Erm… yes? Do you have evidence to the contrary? As it has happened in the past, many, many times, in both directions, why should it be anything other than natural, this time?
I like the play in irony with your moniker, by the way – “There is climate science, And Then There's Physics.” Oh, classic!
Radical Rodent
Mike,
That doesn't really answer my question (which was really just intended to set the basis for what could be an interesting discussion) but I'll assume that we are discussing whether or not the rise in atmospheric CO2 since the mid 1800s is natural or anthropogenic.
Here are some basic points.
1. If Salby is correct that it is mainly a response to an increase in temperature, then about a 1 degree rise in temperature has increased CO2 by 120 ppm. That suggests that there should have been a point in the past when it was negative (or maybe zero). Clearly nonsense. This - as I understand it - is the main reason why most serious scientists don't bother addressing Salby's ideas. They're so obviously wrong as to not really be worth the effort.
2. If we consider the main sources and sinks of CO2, we have ourselves, the oceans, and the biosphere. We emit, but don't absorb, the oceans emit and absorb, and the biosphere emits and absorbs. The oceans and the biosphere absorb more than they emit. We're the only source that emits more than it absorbs (nothing). Hence we are the cause of the rise in atmospheric CO2.
3. The change in C13 to C12 ratio is indicative of a biological source. However, the change in C14 to c12 ratio is indicative of it being a very old biological source (fossils).
There's more, but that's should be good enough.
So, Murry Salby's main claim is that the rise could be natural. It really can't. It's about as certain as something can be. It's also something that is, by and large, accepted by almost everyone. In all seriousness, there are many issues within climate science that are worth discussing and about which there can be lots of disagreement. Whether the rise in atmospheric CO2 is anthropogenic or not, is not one of them.
And Then There's Physics
If Salby is correct that it is mainly a response to an increase in temperature, then about a 1 degree rise in temperature has increased CO2 by 120 ppm.Well, that is the evidence that has been provided by paleoclimate research, though I suspect (as Murry Salby will probably accept) that it is a lot more complex than your own very simplified views, but I think MJ has hit the nail on the head with the “well, of course, everyone knows that…” form of reasoning that you are displaying. “Everyone knew” that the Sun was a chariot driven by a god; “everyone knew” that the Sun and Moon moved around the Earth; “everyone knew” that it was turtles – all the way down! How right has “everyone” been, throughout history?
Science has never been about the consensus, it has almost always challenged it.
Please give some rational explanation as to quite why it cannot be natural. As it has happened in the past, naturally, why is it so different, this time? Supporting evidence would be useful, too.
By the way, as we are actually part of the biosphere, why have you excluded humans from it? Elephants are total emitters of CO2, too, and are also a non-absorber – as are whales, termites and polar bears – in fact, almost ALL animal life is; it is only plants which absorb any CO2. Selecting humans as the culprit in such a way is cherry-picking in its most heinous form.
Radical Rodent
Radical,
Please give some rational explanation as to quite why it cannot be natural.
Hmmm, I rather thought I had (see, at least, points 2 and 3 - even point 1 is an indicator). If, however, those aren't good enough for you, then there's not much more I can do. If you want to believe that it could be natural, that is entirely your right.
Science has never been about the consensus, it has almost always challenged it.
Strange how science is never about the consensus, expect when challenging it.
And Then There's Physics
Radical,
By the way, as we are actually part of the biosphere, why have you excluded humans from it? Elephants are total emitters of CO2, too, and are also a non-absorber – as are whales, termites and polar bears – in fact, almost ALL animal life is; it is only plants which absorb any CO2. Selecting humans as the culprit in such a way is cherry-picking in its most heinous form.
Sorry, missed this. You do realise that I meant our emissions from burning fossil fuels, not our emissions through digestion? Apologies, I thought that was obvious.
And Then There's Physics
No. Point 1 is your reverse linear extrapolation of the complex mathematics Murry Salby uses. While I cannot speak for another person, I am sure that he would be able to answer your argument quite effectively.
Point 2 is covered by the simple fact that ALL animal life emits CO2 and absorbs none.
Point 3: so? Can you definitely say that there can be no natural release of CO2 from fossil sources? I have read from several sources that the human contribution to the rise in CO2 is between 3 – 5% of the total. If this is so, what is causing the remaining 95% of the rise?
Look at one simple fact: CO2 concentrations in the atmosphere are rising inexorably, temperatures are not. While there might be a correlation between the two, this is NOT evidence that they are mutually causative.
What do you find strange about science not being about consensus? Throughout history, science has challenged the consensus – look at Galileo, Newton, Darwin and Einstein as good examples of that.
Radical Rodent
Radical,
Point 1 is your reverse linear extrapolation of the complex mathematics Murry Salby uses. While I cannot speak for another person, I am sure that he would be able to answer your argument quite effectively.
Well, his mathematics isn't complex, but if it rises by 120ppm if temperature rises 1 degree, it should drop by 120ppm if temperatures drop by 1 degree. It doesn't, of course, but that is what Salby is suggesting.
Point 2 is covered by the simple fact that ALL animal life emit CO2 and absorb none.
No, we eat. What we eat has carbon in it. That is the carbon that combines with oxygen to form CO2. That CO2 is then absorbed by plants that we eat or that is eaten by the animals that we eat and by the animals that we don't eat.
Point 3: so? Can you definitely say that there can be no natural release of CO2 from fossil sources?
Okay, this is getting silly now.
And Then There's Physics
What we eat has carbon in it.Can’t argue with that one – but how can that be considered absorbing CO2? ALL animals emit CO2 and absorb none; all absorption of CO2 is undertaken by plants; that an animal then eats that plant does not make the animal an absorber of CO2.
Okay, this is getting silly now.Maybe. But who is the one being silly? I have asked a perfectly reasonable question, to which you could give a reasonable answer, or simply admit that you do not know. There is no shame in ignorance, only in an unwillingness to correct that situation.
Radical Rodent
Radical,
Okay, I'll give a more serious answer. There are 3 sources of CO2, the biosphere (which includes us), our burning of fossil fuels, and the oceans. There are 2 sinks of CO2, the biosphere again (plants absorb CO2, animals eat plants, we eat plants and animals), and the oceans. The biosphere absorbs more than it emits (hence it can't be the source of the increase in atmosphere CO2). The oceans absorb more than it emits (hence it can't be the source of the rise in atmospheric CO2). The only source that emits more than it absorbs is our burning of fossil fuels. Therefore the source of the increase in atmospheric CO2 is our burning of fossil fuels. And, no, fossils aren't emitting CO2 by themselves - or, at least, if they are it is completely negligible.
I really do recommend that you look into this further. The increase in atmospheric CO2 really is a consequence of our burning of fossil fuels. I probably can't say more than I already have, but there are plenty of resources where you can look into this yourself. As I said before, I do think there are interesting aspects of this topic that are worth discussing and worth debating. I don't really think that whether the rise in atmospheric CO2 is anthropogenic or not is one of them.
And Then There's Physics
Salby's Hamburg talk from 33:50
[Note: "native" = "natural" ]
And that brings us to modern changes; those actually observed.
The observed record of CO2 spans the last half-century. (slide 33.58) Extending it back to the proxy record indicates a systematic increase since the nineteenth century. In red (slide 34.21) is delta 13, the relative concentration of the two isotopes, carbon 13 and carbon 12. It has evidences a decline, mirroring the increase of CO2. Together, these proxy records comprise the 'smoking gun' of human emission. Vegetation is slightly leaner in carbon 13 than the atmosphere. So is its ancestor, fossil fuel. Coal and oil each derive from ancient vegetation. Emission from combustion of fossil fuel therefore add CO2 to the atmosphere, enriching its concentration. That's the green curve.
.
The CO2 added however is leaner in carbon 13 than the atmosphere, thereby diluting its concentration. That's the red curve. The glove fits. In truth however, it's but one finger. Combustion of fossil fuel is one of many sources of CO2. Others involve a wide range of native processes. Most are poorly documented. The reasonable interpretation is that opposite changes of CO2 and carbon 13 (the green and the red curve) are the signature of human emission. For this interpretation to be valid, other sources of CO2 - native sources - must have the same concentration of carbon 13 as the atmosphere, which would then be left unchanged. That is, CO2 emitted by native sources must not dilute carbon 13 in the atmosphere. The observed increase of CO2 and decrease in carbon 13 can then follow only from the human sources. In reality, our knowledge of native sources is limited. What we do know is that they are dynamic. Native sources depend intrinsically on environmental conditions: cloud, moisture, temperature. Even on the prevailing ecosystem. Why should we care?This is the estimated contribution from all sources and sinks. (slide 36.39) The human source is of order five gigatons per year. By comparison, the ocean emits of order 90. Land emits another 60. Total emission from native sources is thus of order 150 gigatons per year - 96% of the total is approximately balanced by native sinks which absorb about as much. The key word: approximately because native sources and sinks are two orders of magnitude stronger, even a minor imbalance can overshadow the human sources. Moreover, if those sources involve carbon 13 leaner than the atmosphere, as many do, all bets are off.
(...)
Let there be no ambiguity about what you are looking at. The black curve is just the integral of temperature, scaled by the observed sensitivity of CO2 emission. (slide 50.51) And the sensitivity of emission has been evaluated only from large (word unintelligible) changes that are clearly independent of human emission. The modest discrepancy before 1940, about 10 ppmv, lies well within the sampling uncertainty of the surface network but in light of the agreement during the instrumental era, the last half century it may actually reflect there in proxy CO2. (slide 51.20) It may also reflect limitations of the surface network. At the bottom is coverage of the Earth by surface thermometer. (slide 51.28) It maximises around 1960 at 35%. That's how much of the Earth is land. Before 1960, coverage drops. By 1880, coverage of the Earth by the surface network is less than eight per cent.
The IPCC has proclaimed the following.
"All of the increase in CO2 concentration since pre-industrial times is caused by human activity. The increased CO2 is known to be caused by human activities because the character of the CO2 in the atmosphere, the ratio of its heavy to light carbon atoms has changed in a way that can be attributed to addition of fossil fuel carbon."
The observed sensitivity of native emission of CO2 and carbon 13 make this impossible.
Martin A
I think what is getting a bit silly is the idea that 1C temperature rise equals 120ppm CO2 increase as if there was a simple and direct correlation between the two. Climate is far more complex than that, surely.
How do we account for the fact that (apparently) the highest concentrations of atmospheric CO2 are over places like the Amazon basin rather than, say, the Ruhr Valley, the implication being that the greatest emitters are rotting plants and not coal-fired power stations?
I perhaps should make it clear that I am not necessarily defending Salby "to the death" and nor am I completely convinced that there is no relation between CO2 and temperature which I know is some people's position but I am getting a little tired of the idea that CO2 must be the cause of late 20th century warming because the climate scientists can't be bothered to do the work necessary to find out if there is any other, more plausible explanation.
I say "more plausible" because since CO2 has never been to blame before it seems an incredibly far-fetched coincidence that it should happen now.
In his City Journal article, Darwall makes the point, which would almost certainly be supported by the overwhelming majority of contributors here and by, I believe, the majority of researchers in other disciplines, that good science involves seeking to falsify your own work and assisting those who are of the same mind. The more attempts at falsification fail the stronger the hypothesis becomes. Climate science seeks at every turn to prevent falsification and where alternative views on the science are proposed to rubbish any claim which appears in any way to challenge the consensus.
As you are doing with Salby. He may well be wrong but you are not close to establishing that and won't be for as long as any of us can rebut you by saying "ah yes, but so and so says this ..."
I've just spotted your last reply to RR
Are you sure that the oceans always absorb more than they emit? I seem to have heard the term "outgassing". What does that refer to? And what is the cause of the greening of assorted deserts around the world in recent years?
I'll check on that (or perhaps someone else will) and get back to you tomorrow.
Mike Jackson
The biosphere absorbs more than it emits (hence it can't be the source of the increase in atmosphere CO2). The oceans absorb more than it emits (hence it can't be the source of the rise in atmospheric CO2). The only source that emits more than it absorbs is our burning of fossil fuels.By your logic, it is we humans who are the saviours of the planet – without our releasing vital CO2 into the atmosphere, its concentration would soon drop to zero, and all plant life would cease. It is by the human endeavour of raising CO2 concentrations to levels that plants (the ONLY CO2 “sink” in the biosphere – animals cannot in any way be considered absorbers of CO2) find attractive that life on this planet will thrive. Hooray for us!
Radical Rodent
Martin,
That's not really an argument, as you've just quoted Salby, but - at best - Salby is just confused about the carbon cycle. Let me see if I can explain, but it is getting late. Consider the following (and this is a bit simple, so just illustrative). We have a reservoir of CO2 in the oceans, a reservoir in the biosphere, and we have CO2 in the atmosphere. There is a carbon cycle in which CO2 cycles from the oceans into the atmosphere into the biosphere back into the oceans, etc. Without any additions of CO2 it would reach a steady state where the amount of CO2 in each reservoir (oceans, biosphere) and in the atmosphere would be constant, even though the CO2 would be cycling through the different parts of the system. The individual molecules in each part of the system would change, but the amount in each part would not.
Now, we add some extra CO2 (burn fossil fuels) which has a different C13 to C12 ratio. Initially this would all go into the atmosphere and would change the C13 to C12 ratio. However, over time, this extra CO2 would cycle through the different parts of the system and the C13 to C12 ratio in the atmosphere would change (because it would all get mixed into the oceans and the biosphere). However, the atmospheric concentration would remain higher than before because we've added CO2 to the system.
Now, essentially we're doing this continuously. We burn CO2 that has a different C13 to C12 ratio (and C14, which Salby appears to ignore) than what is already in the system, which adds CO2 to the atmosphere and which then cycles through the oceans, biosphere, atmosphere etc. Therefore, we've increased the total amount of CO2 (therefore the rise is all because of our burning of fossil fuels). So, even though specific CO2 molecules in the atmosphere today aren't because of the burning of fossil fuels doesn't change this.
That's probably as much as I can do here, as it is getting a little late.
And Then There's Physics
Radical,
By your logic, it is we humans who are the saviours of the planet – without our releasing vital CO2 into the atmosphere, its concentration would soon drop to zero, and all plant life would cease.
Okay, I really should just give up, but no. The reason that the oceans and biosphere are absorbing more than they emit is because we keep emitting more. If we weren't, the system would settle into a state where the amount emitted equaled the amount absorded. That's kind of the point.
Mike,
Are you sure that the oceans always absorb more than they emit? I seem to have heard the term "outgassing". What does that refer to? And what is the cause of the greening of assorted deserts around the world in recent years?
I don't know the context of the outgassing, at least in terms of its relevance to today, but the greening is - I think - consistent with the biosphere absorbing some of the excess CO2.
And Then There's Physics
Without any additions of CO2 it would reach a steady state where the amount of CO2 in each reservoir (oceans, biosphere) and in the atmosphere would be constant…
…the system would settle into a state where the amount emitted equaled the amount absorded. [sic]And when in history has this situation ever existed? How did the CO2 concentrations during the last ice age reach levels ten times (or more!) those of the present without humans doing their bit burning “fossil” fuels? Indeed, I have seen valid arguments that CO2 levels are presently recovering from when they were at a perilously low level, seriously damaging the viability of plant life on the planet, so the rise has only to be applauded. Methinks that there could still be flaws in your argument.
Radical Rodent
Martin A
You've partially addressed something I'd hoped that might come up in the discussion. The ratios of the various Carbon isotopes and their sources. Is there any actual data on the mix in 60 G Tons of CO2 from land. I would imagine that a large part is from volcanic sources. The source of that CO2 will be from material sub-ducted which will be depleted in 13C as it will be a very old biological source. There must also be an element of volcanic sourced CO2 in the ocean content due to the large number of sources beneath the sea surface. Most rifts where the tectonic plates are separating fall into that category and I would guess are sources of CO2. So I would assume the isotope mix in land emitted CO2 is different to oceanic CO2 and both are different of from atmospheric CO2. The follow up question is then when were accurate isotopic measurements started?
SandyS
Why doesn't Salby publish his work? I'm sure his supporters will claim that the clisci mafia are supressing it, but there are many outlets possible. Watts or Nova would probably give their back teeth to host his work, maybe the Bishop too. Instead all Salby does is give lectures to people he knows don't understand enough of what he is saying to challenge him - what is that all about? He's had a few years to publish (like Watts and his famous 'paper'), so where is it?
Raff
And the baisc idea of Salby seems nuts. CO2 levels are increasing at twice the rate of our emissions. That means discounting our emissions, they are going down. Yet Radical says they are 'recovering' (upwards)! Go figure.
Raff
That reads wrongly - I'm not suggesting they would really be going down without our emissions, just pointing out Radical's contradiction.
Raff
Radical Rodent.
Without any additions of CO2 it would reach a steady state where the amount of CO2 in each reservoir (oceans, biosphere) and in the atmosphere would be constant…
And when in history has this situation ever existed?
As far as I'm aware the evolution of C4 plant types occured about 25 million years ago, in response to falling CO2 concentrations. C3 plants the majority at about 95% of all biomass need greater than 200ppm to survive. C4 plants are better in low CO2 and more arid conditions and are much better at carbon fixing at about 30% of the total. This suggests that a continuing decline in atmospheric CO2 content and a move to C4 carbon fixing by plants is quite likely without a process which increases CO2 in the atmosphere.
SandyS
You're happy to troll this site; let's see if you have anything constructive to back up your witterings.
Identify Darwall's and Salby's errors.
If you can.