UPDATED – see below
Monckton provides these slides for discussion along with commentary related to his recent post on CO2 residence time – Anthony
There is about one molecule of 13C in every 100 molecules of CO2, the great majority being 12C. As CO2 concentration increases, the fraction of 13C in the atmosphere decreases – the alleged smoking gun, fingerprint or signature of anthropogenic emission: for the CO2 added by anthropogenic emissions is leaner in 13C than the atmosphere.
However, anthropogenic CO2 emissions of order 5 Gte yr–1 are two orders of magnitude smaller than natural sources and sinks of order 150 5 Gte yr–1. If some of the natural sources are also leaner in CO2 than the atmosphere, as many are, all bets are off. The decline in atmospheric CO2 may not be of anthropogenic origin after all. In truth, only one component in the CO2 budget is known with any certainty: human emission.
If the natural sources and sinks that represent 96% of the annual CO2 budget change, we do not have the observational capacity to know. However, we do not care, because what is relevant is net emission from all sources and sinks, natural as well as anthropogenic. Net emission is the sum of all sources of CO2 over a given period minus the sum of all CO2 sinks over that period, and is proportional to the growth rate in atmospheric CO2 over the period. The net emission rate controls how quickly global CO2 concentration increases.
CO2 is emitted and absorbed at the surface. In the atmosphere it is inert. It is thus well mixed, but recent observations have shown small variations in concentration, greatest in the unindustrial tropics. Since the variations in CO2 concentration are small, a record from any station will be a good guide to global CO2 concentration. The longest record is from Mauna Loa, dating back to March 1958.
The annual net emission or CO2 increment, a small residual between emissions and absorptions from all sources which averages 1.5 µatm, varies with emission and absorption, sometimes rising >100% against the mean trend, sometimes falling close to zero. Variation in human emission, at only 1 or 2% a year, is thus uncorrelated with changes in net emission, which are independent of it.
Though anthropogenic emissions increase monotonically, natural variations caused by Pinatubo (cooling) and the great el Niño (warming) are visibly stochastic. Annual changes in net CO2 emission (green, above) track surface conditions (blue: temperature and soil moisture together) with a correlation of 0.93 (0.8 for temperature alone), but surface conditions are anti-correlated with δ13C (red: below).
The circulation-dependent naturally-caused component in atmospheric CO2 concentration (blue above), derived solely from temperature and soil moisture changes, coincides with the total CO2 concentration (green). Also, the naturally-caused component in δ13C coincides with observed δ13C (below).
==============================================================
ADDED (the original MS-Word document sent by Monckton was truncated)
==============================================================
The naturally-caused component in CO2 (above: satellite temperature record in blue, CRU surface record in gray), here dependent solely on temperature, tracks not only measured but also ice-proxy concentration, though there is a ~10 µatm discrepancy in the ice-proxy era. In the models, projected temperature change (below: blue) responds near-linearly to CO2 concentration change (green).
In the real world, however, there is a poor correlation between stochastically-varying temperature change (above: blue) and monotonically-increasing CO2 concentration change (green). However, the CO2 concentration response to the time-integral of temperature (below: blue dotted line) very closely tracks the measured changes in CO2 concentration, suggesting the possibility that the former may cause the latter.
Summary
Man’s CO2 emissions are two orders of magnitude less than the natural sources and sinks of CO2. Our emissions are not the main driver of temperature change. It is the other way about.
Professor Salby’s opponents say net annual CO2 growth now at ~2 μatm yr–1 is about half of manmade emissions that should have added 4 μatm yr–1 to the air, so that natural sinks must be outweighing natural sources at present, albeit only by 2 μatm yr–1, or little more than 1% of the 150 μatm yr–1 natural CO2 exchanges in the system.
However, Fourier analysis over all sufficiently data-resolved timescales ≥2 years shows that the large variability in the annual net CO2 emission from all sources is heavily dependent upon the time-integral of absolute global mean surface temperature. CO2 concentration change is largely a consequence, not a cause, of natural temperature change.
The sharp Pinatubo-driven cooling of 1991-2 and the sharp Great-el-Nino-driven warming of 1997-8, just six years later, demonstrate the large temperature-dependence of the highly-variable annual increments in CO2 concentration. This stochastic variability is uncorrelated with the near-monotonic increase in anthropogenic CO2 emissions. Absence of correlation necessarily implies absence of causation.
Though correlation between anthropogenic emissions and annual variability in net emissions from all sources is poor, there is a close and inferentially causative correlation between variable surface conditions (chiefly temperature, with a small contribution from soil moisture) and variability in net annual CO2 emission.
Given the substantial variability of net emission and of surface temperature, the small fraction of total annual CO2 exchanges represented by that net emission, and the demonstration that on all relevant timescales the time-integral of temperature change determines CO2 concentration change to a high correlation, a continuing stasis or even a naturally-occurring fall in global mean surface temperature may yet cause net emission to be replaced by net uptake, so that CO2 concentration could cease to increase and might even decline notwithstanding our continuing emissions.
Natural temperature change and variability in soil moisture, not anthropogenic emission, is the chief driver of changes in CO2 concentration. These changes may act as a feedback contributing some warming but are not its principal cause.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
If a temp dip does cause a flattening or reversal of CO2 concentration, the game will be once and truly over. By that time (whenever it comes) China alone will likely be exceeding all current Anthro-emissions.
Hoser: “We know the half-life for CO2 in the atmosphere is about 5 years based on bomb 14C (rate constant k= -0.1354 /yr)”
As you observed, that rate constant k= -0.1354 /yr would be consistent with popularly quoted values for the ratio of carbon-dioxide uptake rate to total atmospheric content.
But Gösta Pettersson says at the top of page 5 here: http://www.false-alarm.net/wp-content/uploads/2013/06/paper1.pdf that a regression fit to the bomb data instead indicates a “relaxation time” of 14 +/- 1 years. Although there’s been some nomenclature debate recently, Pettersson says on his page 2 that in this case “the relaxation time will differ less than 5% from the turnover time,” which his page 1 tells us is the reciprocal of the rate constant, so he’s saying the bomb data suggest a half life of around 10 years instead of the 5 years you mention above.
Do you have an alternate source for that 5-year estimate?
Janice Moore: “Is the reason so few of you watch this because the introduction is made in Deutsch? Dr. Salby speaks in English. The lecture is in English.
Is it the fact that I, someone you detest and or whose opinions you do not respect, is the one posting Salby’s lecture?
PLEASE DO NOT LET THE MESSENGER (me) DISTRACT FROM THE MESSAGE (Salby’s lecture).”
Firstly Janice, I’ve seen you name a few times here but have no idea what you stand for and have no reason not to have the neutral ‘respect’ for your opinions that anyone gets until they denote themselves one way or the other. I was unaware you were associate with the presentation. I generally skip the obligatory intro guff on such speeches and fast forward to the meat. Don’t over-rate your own importance.
Germans are generally a rigorous and serious lot (with characters like Ramnsdorf showing that are capable of being rigorously and seriously foolish too. ). German is generally a positive prejudice for me.
My first introduction the Salby’s was his Hamburg lecture, which I found very interesting but annoyingly superficial. I assumed there would be more in publications somewhere. But no.
I listened to it twice in a row to make sure I had not missed the crucial bit where he proved it or referred us to other work. But no.
After seeing the lecture I searched out his email and sent him some suggestions and questions. I got no reply but was later see the U. Macquerie fiasco and realised they would have binned any emails they received to his account.
So yes I did listen to it all (twice). I’m not put off by who introduced it nor by the german language or the fact it happened in Germany. My opinion is based on what he has and HAS NOT presented.
Since you presumably have some means to contact Murry Sably, perhaps you can pass on the message that his credibility is being damaged by his lack of putting something concrete up for inspection. If he is being blocked by gate-keeping he needs to go public via other means. He was claiming to be “weeks away” for publication about 2 years ago. It’s wearing thin.
If he has something that stands up to scrutiny, it could knock AGW hypothesis for six. With the IPCC pushing hard to endebt us for hundreds of $BILLIONS each year for generations to come we need to see it NOW.
TIME TO SEE WHAT HE’S GOT.
Crispin apparently quoting Ferdinand:
“I calculated it some time ago: if the rain absorbs CO2 to saturation at the (cold) place of formation, drops to the ground and evaporates again, 1 mm of rain (1 l/m2) will give an increase of 1 ppmv in the first meter (1 m3) of air. That is all. Simply negligible…”
Since 1 mm of rain is not much that sounds like one helluva transport mechanism and is probably more important than direct absorption at the ocean surface.
This may account at least in part for the asymmetry in the annual cycle
http://climategrog.wordpress.com/?attachment_id=651
It is interesting to note the near linear rise and fall.
Crispin in Waterloo but really in Ulaanbaatar says: November 23, 2013 at 8:33 pm
“Thank goodness this is getting some attention. It is amazing to see such a large CO2 stripping mechanism missing from the conversation.”
Whenever you think of some exciting new mechanism, it’s worth thinking – why would this be making a difference now? It’s been raining for millions of years and the air is not stripped.
I think it may well be a significant flux. Here is just one recent paper considering it. But all it does is shift the steady state a bit.
In the long run fluxes balance, and concentrations adjust to make it happen. We tend to think of the exchange fluxes of CO2 across the sea surface balancing, with CO2 tension the same on each side. But with the rain input, the balance will shift a little. A bit more CO2 in the ocean than otherwise, and a net exchange flux up to balance the rain. That’s how it was.
James Strom says:
Seems kind of harsh to expect Salby to publish in his current circumstances; however, he has said enough to allow others to reconstruct his work. There’s a brief report at The Hokey Schtick with links to a fuller article. This may provide the documentation that some have been looking for.
http://hockeyschtick.blogspot.com/2013/07/swedish-scientist-replicates-dr-murry.html
===
What circumstances is that? He has the times and the means to travel and do public lectures but still does not produce anything hard to back it up.
The link you provided is useful (between the translation and the original for the bits google messes up we get a good idea).
However, this model does not fit that well really and does not include Salby’s ‘ground conditions’, so it is hardly reproducing Sably’s work. Where Sably gets interesting is when he adds that in and gets a much better match. And that’s what we need to see.
UPDATE says: “Absence of correlation necessarily implies absence of causation.”
There is a strong correlation of dCO2 and SST, that has been established several times by different authors. But that does not preclude a different component being present in long term change.
It’s a bit like not removing the seasonal variation and then saying there’s no correlation between other factors which only becomes apparent once you improve the signal to noise ratio by filtering out the annual cycle.
This is a complex interaction and will not be understood by make trivial statements like the above.
Correlation coefficient is simple a measure of the linear relationship between two variables.
Since this relationship contains both a direct (in-phase) component and the orthogonal ( d/dt(CO2) ) component plus a gentle transition from one to the other , probably superimposing several different time constants as deeper ocean layer come into play , we can not draw definitive conclusions from looking at correlation of two simple variables.
Attempts to over simplify will lead to erroneous conclusions.
thanks for the paper link Nick.
” Including these processes, the western equatorial Pacific CO2 flux is modified from an ocean source of +0.019 mol CO2 m−2 yr−1 to an ocean sink of −0.078 mol CO2 m−2 yr−1. ”
Enough to reverse the role of ocean from source to sink in that region.
Unfortunately pay-walled as usual at JRL
Crispin in Waterloo but really in Ulaanbaatar says:
November 23, 2013 at 8:33 pm
Well, here again the calculations:
From:
http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html
the solubility of CO2 in fresh water at 0°C is 3.3 g/kg (or 3.3 g/l which is practically the same) at 1 bar CO2.
The atmospheric pressure of CO2 is 0.0004 bar. Thus at some height where clouds are formed at (very) cold temperatures, the maximum absorbance in cloud drops is 1.32 mg/l.
At the cloud side, 1 l of rain is a lot, it takes many m3 of air to reach that. If water evaporated from a surface of around 30°C, there will be a drop of about 2% water in air into droplets at near 0°C (at sealevel pressure). One m3 of air weights 1.27 kg, thus a drop out of 2.5 g water per m3, or 1 l of water drops out from 400 m3 of air.
The 1.32 mg/l CO2 thus comes out 400 m3 of air. Taking into account the difference in mol weight between CO2 (44) and air (28.6), the drop in CO2 at cloud formation is
1.32 / 1,270,000 / 400 * 44 / 28.6 = near zero ppmv.
Even if I have made a mistake of 6 orders of magnitude, the absorbed amount of CO2 still is undetectable in the 400 ppmv at the height of cloud formation.
The same for the eventually evaporation at ground level: undetectable.
Which doesn’t say that there is no effect of rainwater on carbonate rocks, but even that needs millions of years to carve the undergound holes…
http://climategrog.wordpress.com/?attachment_id=651
The rates of change we see in the annual cycle 14 ppmv/year OUT for about 0.6 of the year and 19 ppmv/year IN for 0.4 of the year and the magnitude of the annual cycle in volume (150Gt) both suggest that annual emissions equivalent to 4ppmv could be absorbed totally, unless things have evolved to just fit the required natural swing.
There will be factor of out-gassing due to steady increase since LIA.
Put the two together and you see a net sink of CO2 due to the presence of emissions as well as a residual long term rise determined by SST. This is the Salby description.
Now whether the natural sinks can absorb that magnitude each year every year without saturating and reducing their capacity to absorb is less clear.
This leads to a less than total absorption of emissions and a long term rise that is a mix of residual and out-gassing. This will still carry a strong correlation with changes in SST.
It has been noted that the percentage of residual emissions has been falling since around 1990. That could indicate that atm CO2 is getting further from equilibrium leading to faster correction (this argues against total absorption) or it could be the result of a more active biosphere (which could be consistent with total absorption).
Sadly not black and white answers, probably a mix of all of those in unknown proportions.
eric1skeptic says:
November 23, 2013 at 5:17 pm
From Bart’s “hard evidence” graph looking at 1997-1998, I see about 0.26 ppm CO2 rise for about 0.18K temperature rise which is a little under 1.5 ppm/K.
Yes, but Bart’s and Salby’s assumption says that the 1.5 ppmv/K is sustained for every year that the increase in temperature above an arbitrary baseline is sustained. According to Bart the 1.5 ppmv/K thus is 1.5 ppmv/K/yr, while Henry’s law is reducing the ppmv/K when the CO2 levels approach the new equilibrium at 16 ppmv/K:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/upwelling_temp.jpg
If Bart and Salby are right, then we have different CO2 rates for every period in time: 0.002 ppmv/K/yr for a glacial-interglacial transition (100 ppmv over 5000 years and 10°C), zero ppmv/K/yr for a glacial period over 90,000 years and zero ppmv/K/year over an interglacial period of 10,000 years, 0.15 ppmv/K/yr for the MWP-LIA transition (6 ppmv, 0.8 K, 50 years) and again zero ppmv/K/yr for most of the Holocene. But nowadays we have a sudden increase of 1.5 ppmv/K/yr over the past 50 years…
If you look at the past 800 kyr in ice cores, it is a lot simpler if one starts from an equilibrium reaction of around 8 ppmv/K, that fits all changes over all time periods, except the current one. The difference: human emissions.
http://www.esrl.noaa.gov/gmd/webdata/ccgg/trends/co2_data_mlo_anngr.pdf
It is interesting that the warmists have ignored the fact that the rate of increase in atmospheric CO2 does not correlate with in the rate of increase of anthropogenic CO2. To explain the observations assuming there is very little mixing of the deep ocean with the surface ocean water which is the warmist’s assumption, the CO2 sink must increase in percentage absorbed (i.e. not just absorb more to maintain the same percentage of absorption but rather increase the amount of CO2 that is absorbed, which does not make sense based on the warmist theory.)
Comment: Note anthropogenic CO2 emissions have increased 58% from 1990 yet there is only a 25% increase in the rate of atmospheric CO2 rise from 1990. Also note that the yearly change in CO2 correlates directly with ocean temperature and does not correlate with anthropogenic CO2 emissions. Look at the above graph and below data and try to explain the change in the yearly rate of change (increase in atmospheric CO2).
Key to understanding what is happening is the amount of mixing of the deep ocean water with the surface ocean waters. If there is more mixing of the deep ocean with the surface ocean waters, the anthropogenic CO2 is mixed with a much larger reservoir of carbon which dampens the impact due to size of the deep ocean carbon reservoir.
The analysis of the C14 data indicates that there is significant mixing the deep ocean and surface ocean waters based on the very low C14 value that is reached. If the C14 was mixing only with the surface ocean water it would reach a higher plateau value (the surface ocean carbon reservoir is 700 Pct as compared to the atmosphere carbon of 750 Pct and the deep ocean is carbon reservoir 38,000 Pct.
In order for there to be heat hiding in the deep ocean there must be significant mixing of the surface ocean waters with the deep ocean waters. The implication of mixing surface ocean water with deep ocean water is that the anthropogenic CO2 increase is mixed with a much larger reservoir which significantly reduces the impact of the anthropogenic CO2 emissions. If the planetary temperature drops there will be a significant reduction in atmospheric CO2.
Now if there is significant mixing of surface ocean water with deep ocean water, a significant portion of the observed CO2 rise in the atmosphere is the result of the increase in temperature of the ocean – as Salby asserts – rather than due to anthropogenic CO2 increases. I can explain the C13 changes if someone is interested.
1980 1.73 1990 1.19 2000 1.62 2010 2.45
1981 1.43 1991 0.99 2001 1.58 2011 1.84
1982 0.96 1992 0.48 2002 2.53 2012 2.66
1983 2.13 1993 1.4 2003 2.29
1984 1.36 1994 1.91 2004 1.56
1985 1.25 1995 1.99 2005 2.52
1986 1.48 1996 1.25 2006 1.76
1987 2.29 1997 1.91 2007 2.22
1988 2.13 1998 2.93 2008 1.6
William Astley says:
November 23, 2013 at 6:01 pm
You are stating nonsense. The percentage of CO2 absorbed by the ocean must increase to explain the observations. The IPCC models predicted that the percentage of CO2 absorbed by the ocean will decrease due to increasing ocean temperature and increased ph of the ocean.
Did I say that the IPCC is right? To the contrary. The observations show that the deep oceans are far from saturated and indeed increase their uptake over time in ratio with the increased pressure of CO2 in the atmosphere. Temperature and pH play a role for most of the ocean surface, which is saturated at 10% of the change in the atmosphere. But the sink rate into the deep oceans near the poles are hardly affected by temperature or pH, neither is the uptake by plants.
I see from your comment that you have are completely ignorant concerning the deep methane hypothesis for the formation and evolution of the earth’s atmosphere and oceans.
No matter if the deep earth methane theory is right or wrong, the current methane injection into the atmosphere is near constant over the last decade, thus not the cause of in increasing decline rate of δ13C
http://en.wikipedia.org/wiki/File:Mlo_ch4_ts_obs_03437.png
BTW, the CH4 levels in the previous interglacial were around 700 ppbv at higher temperatures than today. We are currently at 1800 ppbv, the difference certainly is man-made too…
Ferdi, two problems with you back of envelop figures:
“If water evaporated from a surface of around 30°C, there will be a drop of about 2% water in air into droplets at near 0°C (at sealevel pressure).”
a) Clouds do not usually form at SLP but at the tropopause.
b) what are you calculating anyway?
This not a once in a lifetime event , it is a continual process. What you need to show is the integral of how much per year is removed or how this will affect the equilibrium.
Your result has the right units but what does it represent physically?
Ferdinand Engelbeen says: November 24, 2013 at 2:20 am
“Well, here again the calculations:…”
I think it is not nothing. On average every m2 gets about a m^3 of rain in a year. 1.32 mg/l is 1.32 gm/m2/yr. On 5e14 m2 earth, that’s 0.66Pg, or 0.66 Gton CO2/yr. That’s about 1.5% of human emissions. Actually, similar to volcano. Not much, but…
“BTW, the CH4 levels in the previous interglacial were around 700 ppbv at higher temperatures than today. We are currently at 1800 ppbv, the difference certainly is man-made too…”
Oh certainly! So by the same logic the fact that the length of day is now longer than during that period is our fault too? OMG we’re going stop the Earth turning unless we act NOW !
“I think it is not nothing. On average every m2 gets about a m^3 of rain in a year. 1.32 mg/l is 1.32 gm/m2/yr. On 5e14 m2 earth, that’s 0.66Pg, or 0.66 Gton CO2/yr. That’s about 1.5% of human emissions. Actually, similar to volcano. Not much, but…”
Thanks, Nick, that is starting to sound more meaningful. Now we need to look at point a)
I think the 2% he based this on will be substantially different at tropopause pressures.
” I can explain the C13 changes if someone is interested.”
I’m interested.
Hoser says:
November 23, 2013 at 6:06 pm
It is much more likely biology is quite capable of handling a slight imbalance of CO2 such as the human contribution. The increase in CO2 is probably due to a shift in the equilibrium.
The whole biosphere evoluated from a slight source before the 1990’s to a slowly increasing sink since 1990. That is calculated from the oxygen balance:
http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf
There are no signs that the turnover time (amount in the atmosphere divided by throughput) did change over time: recent estimates even give a slightly longer residence time than older estimates, which is when atmospheric levels increase for a constant throughput.
The current human part is around 9% of total CO2, even if 100% of the increase is man-made, because the residence time of individual molecules is only ~5 years, but the e-fold decay rate from an injection of extra CO2 is ~50 years:
For a 100 GtC pulse 160 years ago:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/fract_level_pulse.jpg
where FA is the remaining fraction of anthro CO2 in the atmosphere, FL in the ocean surface, tCA total carbon and nCA “natural” carbon in the atmosphere. After ~60 years all “human” CO2 disappeared and is replaced by natural CO2, but still the total increase of CO2 above equilibrium is from the human input.
Here for the human input over the past 160 years:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/fract_level_emiss.jpg
“If Bart and Salby are right, then we have different CO2 rates for every period in time: 0.002 ppmv/K/yr for a glacial-interglacial transition (100 ppmv over 5000 years and 10°C), zero ppmv/K/yr for a glacial period over 90,000 years and zero ppmv/K/year over an interglacial period of 10,000 years, 0.15 ppmv/K/yr for the MWP-LIA transition (6 ppmv, 0.8 K, 50 years) and again zero ppmv/K/yr for most of the Holocene. But nowadays we have a sudden increase of 1.5 ppmv/K/yr over the past 50 years…”
Ferdi, you are trying to make it sound ridiculously complicated and thus illogical and improbable.
Here’s a more sensible way to look at the same figures:
zero ppmv/K/yr for a glacial period over 90,000 years and zero ppmv/K/year over an interglacial period of 10,000 years
0.002 ppmv/K/yr for a glacial-interglacial transition (100 ppmv over 5000 years and 10°C)
> 5000 years system has equilibrated. Circa 800 y lag in ice record suggests a circa 800y time constant. Five time constants (4000y) >99% final value.
The last interglacial transition was not a one way 5000 year event , it included an almost total reversal in Y-D event so that time period may be shorter for 0.002 ppmv/K/yr but of the order of 1000 years.
“and again zero ppmv/K/yr for most of the Holocene.”
Within the resolution of the data a fairly stable period in moderate equilibrium. We don’t have decadal scale resolution to compare with recent years, so we can’t do it.
” 0.15 ppmv/K/yr for the MWP-LIA transition (6 ppmv, 0.8 K, 50 years) ”
Unlike 5000 years, 50 years will not equilibrate with the deep oceans. What we are seeing here is the smaller volume of moderate depths. This will result in strong , faster response. We are not looking at a 800 time constant here !
My plots of dCO2 vs SST derived 8ppm/K/year as an even shorter inter-annual response an 4ppmv/K/year inter-decadal.
All that seems totally consistent and simply implies different time-scales for different depths as would be expected.
Your suggestion that a one-size-fits-all model can be applied to 10 and 50 year change as well a 5000 years is, on the other hand, clearly unrealistic physically.
“but the e-fold decay rate from an injection of extra CO2 is ~50 years:”
Where do you get that figure from?
why do I care about a graph unless I know where it comes from and the assumption upon which it is based?
Greg Goodman says:
November 24, 2013 at 3:14 am
a) Clouds do not usually form at SLP but at the tropopause.
Agreed, but it is maximum 3% water in air at evaporation in hot equatorial waters, if that all drops out, it is 50% more than calculated, still negligible for local measurements.
b) what are you calculating anyway?
This not a once in a lifetime event , it is a continual process. What you need to show is the integral of how much per year is removed or how this will affect the equilibrium.
I have calculated it on the base that in the past several insisted that e.g. the Mauna Loa readings may be affected by (local) rain and local levels near-ground. But locally the change in levels is completely unimportant.
Because the total mass on the move is gigantic, the CO2 mass movement indeed (as Nick says) is not negligible. But the residence time of water is only a few days in the atmosphere. Thus any change in water circulation (and transported CO2) will rain out in a few days. If there are no changes in difference between inputs and putputs, which is hardly possible for the water cycle, there is no change in CO2 levels of oceans, atmosphere, rivers, etc.
Even if global warming increased the water cycle with 10%, it doesn’t make a difference in CO2 levels and the 10% increase in CO2 mass circulation may increase rock weathering, but that still is negligible for the carbon balance…
Greg Goodman says:
November 24, 2013 at 3:20 am
Oh certainly! So by the same logic the fact that the length of day is now longer than during that period is our fault too? OMG we’re going stop the Earth turning unless we act NOW
As usual, I do know more than I wrote… But you are right to ask for the background of where that is based on.
From 420 kyr (Vostok) ice cores, there is a quite nice ratio of methane with temperature over glacial-interglacial transitions. That changed around 1860, completely parallel with the onset of fossil fuel use, as is the case for CO2 too:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_ch4.jpg
The Law Dome DSS core has a resolution of ~20 years, thus spanning the MWP-LIA transition. The other cores less than a decade.
Maybe just coincidence that after 420,000 years (800,000 years for CO2) CH4 and CO2 levels start to increase at the moment that humans start to use fossil fuels, but I don’t believe in such coincidences…
Thanks Ferdi. You have some useful stuff. It would be great if I did not have to prod you for sources all the time.
Doesn’t CH4 match the ‘plateau’ in temps quite well too?