Readers may recall these WUWT stories: Earth’s biosphere booming, California’s giant redwoods inconveniently respond to increased carbon dioxide, and Forget deforestation: The world’s woodland is getting denser and change could help combat climate change. NASA satellite imagery pointed this out long ago.
Now confirmation from another source: From the University of Colorado at Boulder
Earth absorbing more carbon, even as CO2 emissions rise, says CU-Boulder-led study
Planet’s carbon uptake doubles in past 50 years, researchers ponder how long trend can continue
Despite sharp increases in carbon dioxide emissions by humans in recent decades that are warming the planet, Earth’s vegetation and oceans continue to soak up about half of them, according to a surprising new study led by the University of Colorado Boulder.
The study, led by CU-Boulder postdoctoral researcher Ashley Ballantyne, looked at global CO2 emissions reports from the past 50 years and compared them with rising levels of CO2 in Earth’s atmosphere during that time, primarily because of fossil fuel burning. The results showed that while CO2 emissions had quadrupled, natural carbon “sinks” that sequester the greenhouse gas doubled their uptake in the past 50 years, lessening the warming impacts on Earth’s climate.
“What we are seeing is that the Earth continues to do the heavy lifting by taking up huge amounts of carbon dioxide, even while humans have done very little to reduce carbon emissions,” said Ballantyne. “How long this will continue, we don’t know.”
A paper on the subject will be published in the Aug. 2 issue of Nature. Co-authors on the study include CU-Boulder Professor Jim White, CU-Boulder doctoral student Caroline Alden and National Oceanic and Atmospheric Administration scientists John Miller and Pieter Tans. Miller also is a research associate at the CU-headquartered Cooperative Institute for Research in Environmental Sciences.
According to Alden, the trend of sinks gulping atmospheric carbon cannot continue indefinitely. “It’s not a question of whether or not natural sinks will slow their uptake of carbon, but when,” she said.
“We’re already seeing climate change happen despite the fact that only half of fossil fuel emissions stay in the atmosphere while the other half is drawn down by the land biosphere and oceans,” Alden said. “If natural sinks saturate as models predict, the impact of human emissions on atmospheric CO2 will double.”
Ballantyne said recent studies by others have suggested carbon sinks were declining in some areas of the globe, including parts of the Southern Hemisphere and portions of the world’s oceans. But the new Nature study showed global CO2 uptake by Earth’s sinks essentially doubled from 1960 to 2010, although increased variations from year-to-year and decade-to-decade suggests some instability in the global carbon cycle, he said.
White, who directs CU-Boulder’s Institute of Arctic and Alpine Research, likened the increased pumping of CO2 into the atmosphere to a car going full throttle. “The faster we go, the more our car starts to shake and rattle,” he said. “If we drive 100 miles per hour, it is going to shake and rattle a lot more because there is a lot more instability, so it’s probably time to back off the accelerator,” he said. “The same is true with CO2 emissions.”
The atmospheric CO2 levels were measured at 40 remote sites around the world by researchers from NOAA and the Scripps Institution of Oceanography in La Jolla, Calif., including stations at the South Pole and on the Mauna Loa Volcano in Hawaii.
Carbon dioxide is emitted into the atmosphere primarily by fossil fuel combustion and by forest fires and some natural processes, said Ballantyne. “When carbon sinks become carbon sources, it will be a very critical time for Earth,” said Ballantyne. “We don’t see any evidence of that yet, but it’s certainly something we should be looking for.”
“It is important to understand that CO2 sinks are not really sinks in the sense that the extra carbon is still present in Earth’s vegetation, soils and the ocean,” said NOAA’s Tans. “It hasn’t disappeared. What we really are seeing is a global carbon system that has been pushed out of equilibrium by the human burning of fossil fuels.”
Despite the enormous uptake of carbon by the planet, CO2 in the atmosphere has climbed from about 280 parts per million just prior to the Industrial Revolution to about 394 parts per million today, and the rate of increase is speeding up. The global average of atmospheric CO2 is expected to reach 400 ppm by 2016, according to scientists.
The team used several global CO2 emissions reports for the Nature study, including one by the U.S. Department of Energy’s Carbon Dioxide Information Analysis Center. They concluded that about 350 billion tons of carbon — the equivalent of roughly 1 trillion tons of CO2 — had been emitted as a result of fossil fuel burning and land use changes from 1959 to 2010, with just over half moving into sinks on land or in the oceans.
According to the study, the scientists observed decreased CO2 uptake by Earth’s land and oceans in the 1990s, followed by increased CO2 sequestering by the planet from 2000 to 2010. “Seeing such variation from decade to decade tells us that we need to observe Earth’s carbon cycle for significantly longer periods in order to help us understand what is occurring,” said Ballantyne.
Scientists also are concerned about the increasing uptake of CO2 by the world’s oceans, which is making them more acidic. Dissolved CO2 changes seawater chemistry by forming carbonic acid that is known to damage coral, the fundamental structure of coral reef ecosystems that harbor 25 percent of the world’s fish species.
The study was funded by the National Research Council, the National Science Foundation and NOAA.
A total of 33.6 billion tons of CO2 were emitted globally in 2010, climbing to 34.8 billion tons in 2011, according to the International Energy Agency. Federal budget cuts to U.S. carbon cycle research are making it more difficult to measure and understand both natural and human influences on the carbon cycle, according to the research team.
“The good news is that today, nature is helping us out,” said White also a professor in CU’s geological sciences department. “The bad news is that none of us think nature is going to keep helping us out indefinitely. When the time comes that these carbon sinks are no longer taking up carbon, there is going to be a big price to pay.”
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Ferdinand Engelbeen says:
August 3, 2012 at 8:55 am
Such a test is far from reality as doing that, you alter the equilibrium because pure limestone is undersaturated in CO2 and you increase the pH and thus the buffer capacity…
——————————————————
So you admit then, that a body of water (in my case the aquarium example in the above discussion) in contact with an enormous source of limestone would give a much different result that an isolated body of water that has no limestone (think all of the CAGW experiments) since the undissolved limestone greatly increase the buffer capacity.
Well, the ocean is in contact with many millions of gigatons of limestone….. the source of almost all the buffer capacity in the ocean. Yet, you claim that by doing (and referencing to) experiments that totally NEGLECT the limestone are valid and mimic the real world.
HenryP says:
August 3, 2012 at 10:02 am
From the link I provided:
Equation 4:
The constant KH is called the Henry’s Law constant. The Henry’s Law relation shows that carbonic acid concentration is directly proportional to atmospheric CO2 partial pressure.
From CDIAC ( http://cdiac.ornl.gov/ftp/co2sys/CO2SYS_calc_DOS_Original/co2sys.txt ):
K0 [note: KH in the above equation 4], the solubility of CO2 in seawater, is from Weiss (1974), who combined the measurements of Murray and Riley (1971) with some of his own and fit the resulting data. Estimates of the accuracy of K0 vary from 0.2% (Weiss 1974) to 0.5% (Dickson and Riley 1978).
Thus the formula to calculate the solubility of CO2 in seawater was established near 40 years ago and is based on real measurements…
Alcheson says:
August 3, 2012 at 1:21 pm
So you admit then, that a body of water (in my case the aquarium example in the above discussion) in contact with an enormous source of limestone would give a much different result that an isolated body of water that has no limestone (think all of the CAGW experiments) since the undissolved limestone greatly increase the buffer capacity.
If you have an aquarium with fresh water and you add limestone and CO2, you will have a complete different experiment than with seawater, which is already in equilibrium with limestone. Adding limestone tp seawater will have no effect.
Adding CO2 to seawater with and without limestone also are different experiments which will show different results (but many experiments used limestone…).
And worse, adding a strong acid to lower the pH (as was done in several experiments) is not comparable at all with adding CO2…
Dear Ferdinand
I commend you on your persistence. But as I pointed out to Duster, all the chemical reactions involving the oceans’ water and carbondioxide, including the final one, forming calcium carbonate, are dependent on temperature. The natural global warming that occured from ca. 1945-1995-as seen from the energy input by the sun – was due to more SW coming through, mostly absorbed into the waters/
I noticed from my own swimming pool, if I have the pump off during the day, that this heat accumulates in the top layer(s). You cannot use “average* temps. with Henry’s law because the reality is much, much different.
Sorry, but you have not shown me how much of that 70 ppm’s was due to natural warming…
It doesn’t look like ocean pH is measurably changing.
Henry@Smokey
Certain things in life are not measureable due to limitations in equipment. pH is one.
Slabadang says:
August 2, 2012 at 9:29 am
What are they really saying and why do they express themseves as they do?
They admit 1. That there is an unbalance in the earth carbon sinks and that there are
2 “some natural sources and 3 They DONT relate the level of co2 in the atmosfhere to
temperature it self. They are simply trying to create another interpretaion af what
Murry Salby discovered and the pure “hit the bullshit botton” is this::
“It is important to understand that CO2 sinks are not really sinks in the sense that the extra
carbon is still present in Earth’s vegetation, soils and the ocean,” said NOAA’s Tans. “It
hasn’t disappeared. What we really are seeing is a global carbon system that has been
pushed out of equilibrium by the human burning of fossil fuels.”
Well you know temperature itself does that and when theese “scientists” can calculate at
what temperature the global sinks is in “eqilibrium” they are wecome , because they dont
have a clue what they are talkning about or how the “natural processes work” or how much
of the co2 increase comes from humans or natural.
Salby gave another seminar at the Sydney Institute.
http://www.thesydneyinstitute.com.au/speaker/murry-salby/
It pulls the rug out from under climate models and CO2 in them.
Ferdinand Engelbeen says:
August 3, 2012 at 2:01 pm (but many experiments used limestone…)
——————————————————
Please be so kind as to link a couple references. None I have read so far used limestone. I would like to read a couple and evaluate them.
I do agree that adding a strong acid is not comparable at all to adding CO2, and I never claimed it was.
I strongly disagree that solid limestone sources are no longer of any importance to ocean chemistry as you imply above.
As CO2 goes up, pH changes or ocean temperature changes, carbonates can either dissolve or deposit. As I showed earlier, if you hold the pH constant, you can readily change the CO3^2- by adding CO2 so long as you have carbonate solids (limestone or other sources) available. Remember Ka = [H][CO3]/[HCO3] => Ka/[H]= [CO3]/[HCO3]. Since pH is constant, Ka/[H] is a constant and therefore, as [HCO3] increases due to higher CO2 in the air, [CO3–] in the ocean also must increase.
At pH 8.2, if you bubble in sufficient CO2 into a limestone solution, CaHCO3 is soluble to the tune of 160g/liter so to say that limestone deposits are no longer of concern to ocean chemistry and CO2 is unlikely to be an accurate statement.
Therefor, you must have excess limestone in your experiments, as you find in the ocean, if you want to run a valid experiment in my opinion.
Ferdinand Engelbeen says:
August 3, 2012 at 1:05 am
“… a similar plot can be obtained by completely removing the temperature trend and adding a % of the emissions.”
Can’t. Phase doesn’t match. The temperature leads CO2, which means that you are proposing an anti-causal relationship, which is not possible in this particular universe.
“And it doesn’t work for any other period of time than the current one…”
A) These are the most reliable CO2 measurements we have, and we have no way to verify proxy reconstructions before 1958. The relationship has held in the modern era since 1958 and, since that is the time in which the greater part of the rise in CO2 occurred, it follows at the very least that human CO2 production is not responsible for that greater part of the rise in CO2.
B) CO2eq is not necessarily, or even generally, a constant. We do not know its value or values pre-1958, we only know that it was close to a particular range of values proportional to the temperature anomaly since then. And, that information is enough to exonerate human culpability for the lion’s share of the rise in CO2.
“…simply because we had a near parallel increase of temperature and CO2 rate of change, that gives a completely spurious correlation.”
You have no basis for claiming the correlation is spurious, and the odds that it is a spurious correlation, given that all those years matched so closely, are infinitesimal.
“Any temperature change of the oceans has a limited effect of maximum 16 ppmv/°C, no matter if that comes from the ocean surface alone or the deep oceans.”
That violates mass balance. If new CO2 rich waters are constantly entering the surface system, then CO2 will accumulate in the atmosphere until such as time as CO2 downwelling matches CO2 upwelling. Current data show that upwelling content is much greater than downwelling. Before long, the atmosphere, land, and oceans are doing Lucy’s bit with the chocolates.
Everything anyone needs to know to determine that CO2 concentration is being regulated naturally is contained in this plot.
Correction to Bart @ur momisugly August 3, 2012 at 7:03 pm:
“We do not know its value or values pre-1958, we only know that it was close to a particular range of values proportional to the integral of the temperature anomaly since then.”
Henry@Bart
That was an interesting plot. I knew/figured that temperature leads CO2, of course, but I had not seen that plot. Now you might be interested in something else I figured (but I don’t have the plot, yet)
I think the global warming- and subsequent global cooling periods of ca. 50-51 years each are caused by decreasing and increasing ozone levels, respectively. Lower ozone allows more SW of higher energy (<0.3 um) through which get absorbed in the oceans and is transferred to heat. We are now entering a period of cooling as ozone levels are increasing again.
Obviously, it seems that this is all happening because of changes on the sun. Either more ozone is produced or the atmosphere is shrinking a bit, causing said increase.
HenryP says:
August 3, 2012 at 2:10 pm
You cannot use “average* temps. with Henry’s law because the reality is much, much different.
Sorry, but you have not shown me how much of that 70 ppm’s was due to natural warming…
At any place of the sea surface, an increase of 1°C will give an increase of ~16 microatm in pCO2 of the surface waters. The ~16 microatm changes somewhat with the local temperature, salinity and pH, but that doesn’t make the bulk of the change.
For the hot equatorial waters, that would give an increase of ~16 microatm on top of the maximum 750 microatm already measured there. For the cold polar waters, the 16 microatm comes on top of 150 microatm minimum measured there.
The net effect is that the driving force which pushes more CO2 into the atmosphere from the hot Pacific waters is increased from 750 – 400 = 350 microatm to 365 microatm, thus giving an increase of 4% in differential pressure and thus 4% more CO2 input flow (input to the atmosphere).
The reverse happens at the poles: the sink rate in the cold polar waters is reduced with 11%:
400 – 250 = 150 is reduced to 400 – 265 = 135 microatm partial pressure difference.
The increase of inflow at one side and the decrease of outflow at the other side gives an increase of CO2 in the atmosphere, but that increase ends when the partial pressure of CO2 in the atmosphere increases so much that the initial pressure differences are reached again. That is with an increase of 16 microatm in the atmosphere, or ~16 ppmv.
It doesn’t matter much that at some areas the seawater temperature will increase more than at other places, but to compensate for such differences, the area weighted averages are used for temperature, pCO2, average wind speed and fluxes.
@ferdinand meeus Engelbeen August 4, 2012 at 2:17 am
Thank you so much for that calculation. Knowing a little bit about factors affecting CO2 solubility I’ve longed to come up with such figures, but always struggled with the complexity of it.
Alcheson says:
August 3, 2012 at 4:38 pm
Direct from nature:
http://www.co2.ulg.ac.be/recifeng.htm
But this is not my usual point of study…
At pH 8.2, if you bubble in sufficient CO2 into a limestone solution, CaHCO3 is soluble to the tune of 160g/liter so to say that limestone deposits are no longer of concern to ocean chemistry and CO2 is unlikely to be an accurate statement.
If you bubble pure CO2 into a solution, the pCO2 is 1 million microatm, quite a difference for the equilibria, compared to an atmospheric CO2 doubling where you go from 300 microatm to 600 microatm. In your experiment, the pCO2 pressure is 1700 times higher than an atmospheric CO2 doubling…
Just read somewhere that at the temperature and salt/carbonate content of the North Sea, only at 1000 ppmv in the atmosphere CaCO3 will start to dissolve…
Bart said:
“If new CO2 rich waters are constantly entering the surface system, then CO2 will accumulate in the atmosphere until such as time as CO2 downwelling matches CO2 upwelling. Current data show that upwelling content is much greater than downwelling.”
Could Ferdinand address that point please ?
With both sinks and sources for CO2 varying greatly over time I cannot really envisage such a simple scenario as a 1C water temperature rise always giving a maximum 16ppm CO2 rise in the atmosphere.
Simply put, if the absorption capacity of water falls as a result of warming then CO2 in the air will be blocked from entering the water as fast as would otherwise have been the case.
If, in the meantime, the wide variety of other natural sources of CO2 in the air are speeding up due to that warming then we have to add together the extra CO2 left in the air by the warmer water plus the additional excess being produced by the sources.
Furthermore Murry Salby doesn’t limit his findings to the ocean surface. He also introduces the soil moisture content across the globe. Warming over land during the day and in summer or during a general long term warming trend such as that from LIA to date being much greater than warming over oceans the CO2 response from warmer soil moisture would be larger than that from the oceans.
I cannot see how that would all be capped at 16ppm per 1C temperature rise.
Is Ferdinand only considering the response to the initial warming of a static parcel of water and ignoring the the disproportionate effect involving soil moisture and the response of the other CO2 sources to that warming (especially biosphere acceleration) ?
That extra 1C doesn’t just slow down the water uptake of CO2 as Ferdinand seems to think. It also perks up all the natural sources to cause a much bigger backing up within the system than just 16ppm.
Ferdinand Engelbeen says
http://wattsupwiththat.com/2012/08/02/earths-co2-sinks-increasing-their-uptake/#comment-1051232
I appreciate your comment as I am always willing to learn. Unfortunately I believe the reality is different.
First of all, what I learned from my initial tables, is that global warming was driven by increasing maxima, not increasing minima. If CO2 had anything to do with the global warming it would have been minima pushing up the means.
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
Next I learned that there have always been periods of 50 or 51 years where there is this natural global warming and global cooling cycle.
http://www.letterdash.com/henryp/global-cooling-is-here
Hence the significance of 50 year periods in the Jewish faith. (7 x7 +1 Jubilee year) – Moses must have picked this up from the Egyptians who were experts on the sun’s cycles.
Obviously, being in a global warming cycle, earth has its own balancing system to keep things in check (so we might have life – at all- or afterall ): …..the weather….
http://wattsupwiththat.com/2010/07/24/willis-publishes-his-thermostat-hypothesis-paper/
(if you have never read this paper, you should plan for it to read it sometime)
More global warming simply meant more storms, and more and/or bigger weather systems, developing over the oceans to equalize the heat over all the earth. Now, I am not sure if you have ever seen what happens with a storm over the sea,
but at the centre the pressure is so low that the water boils, thereby vaporising the water…… and this is exactly what happens when we boil water in a kettle.
Now, any chemistry student knows that the first smoke from the (warmed) water in a kettle is the CO2 being released. In fact, we were taught even to boil de-ionised water to remove the CO2. Exactly the same thing happens in “the weather”.
So here we come to cause and effect, get it? Smoking causes cancer but cancer does not cause smoking. My conclusion: Natural warming also causes an increase in CO2. How much is that? How much (of the 70 or 80 ppm’s increase since 1960) was that, exactly?
I believe given the number of variables and untested factors, you would be wise to say that it is simply incalculable.
Well as the token lay person.
The way i see it is that Mother Nature her name isnt Giha its Goldylocks.
Basically she dosent like it too hot or too cold.Basically shes always got her hand on the Thermostat keeping things just right..
3 Bears ?
Bart says:
August 3, 2012 at 7:03 pm
Can’t. Phase doesn’t match. The temperature leads CO2, which means that you are proposing an anti-causal relationship, which is not possible in this particular universe.
Temperature indeed leads CO2 with a few months, see in more detail:
http://www.woodfortrees.org/plot/esrl-co2/isolate:60/mean:12/scale:0.2/from:1990/plot/hadcrut3vgl/isolate:60/mean:12/from:1990
Your plot doesn’t show the same lead, as you compare the derivative of the CO2 levels to the temperature plot. For the same detail, even seems to precede the temperature in some cases:
http://www.woodfortrees.org/plot/esrl-co2/derivative/mean:12/from:1990/plot/hadsst2gl/from:1959/scale:0.3/offset:0.1/from:1990
But the derivative of the temperature, again shows the same lag as expected:
http://www.woodfortrees.org/plot/esrl-co2/derivative/mean:12/from:1990/plot/hadsst2gl/from:1959/scale:5/offset:2/from:1990/derivative/mean:12
That shows the same variability of CO2 as result of temperature variability, without any substantial influence on the trend itself. Because the latter is caused by the human emissions, not the temperature trend…
A) These are the most reliable CO2 measurements we have, and we have no way to verify proxy reconstructions before 1958.
Of course, if you ignore data you don’t like… Ice core data are reliable, direct measurements of ancient air, be it averaged over several years to many centuries. For the period 1850-1960 with sufficient resolution (~8 years in two Law Dome ice cores), including an overlap of ~20 years (1960-1980) with direct measurements at the South Pole. The reproducability is within 1.2 ppmv (1 sigma) for different samples at the same gas age of the two cores (+ a third core with less resolution) and the atmosphere for the overlapping period:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_sp_co2.jpg
The relationship has held in the modern era since 1958 and, since that is the time in which the greater part of the rise in CO2 occurred, it follows at the very least that human CO2 production is not responsible for that greater part of the rise in CO2
The relationship is real for the variability in sink rate, but completely spurious for the trend. It violates the mass balance (where does the human CO2 get?) and there is no known natural process that can deliver a continuous stream of CO2 for a small increase in temperature (see further for the deep ocean upwelling).
B) CO2eq is not necessarily, or even generally, a constant. We do not know its value or values pre-1958
Whatever you think about ice cores, there is a strong relationship between the temperature proxy and the direct CO2 measurements over the past 800 kyear. That relationship didn’t change over the full 800 kyr period, neither over more detailed periods like the MWP-LIA. It is constrained around 8 ppmv/°C. Even if the resolution is wide (560 years in the Dome C record, 21 years in the Law Dome DSS record), any higher frequency variability would be problematic for plants at the low side during 100 kyr of glacial periods, thus quite unlikely.
Thus CO2eq is quite stable over periods from a few decades to many millennia, even if the real ratio (temperature in this case is a proxy for the SH oceans) may be somewhat higher or lower.
You have no basis for claiming the correlation is spurious, and the odds that it is a spurious correlation, given that all those years matched so closely, are infinitesimal.
– There is no known natural process that produces 70 ppmv CO2 from a temperature increase of 0.6°C.
– The same close relationship can be obtained by the sum of two variables: temperature changes and emissions. The latter alone gives a much better correlation with the trend than temperature alone over the past 104 years:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_2004.jpg
and
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_co2_1900_2004.jpg
In the latter trend one can see that a fast interannual temperature change of halve the scale has a small effect on the CO2 levels, but the whole trend would give a huge change in CO2 over the past 104 years, while a change over 50 years (MWP-LIA) with a 21 years resolution only shows a 6 ppmv change for a drop of ~0.8°C over a few centuries:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_1000yr.jpg
That violates mass balance. If new CO2 rich waters are constantly entering the surface system, then CO2 will accumulate in the atmosphere until such as time as CO2 downwelling matches CO2 upwelling. Current data show that upwelling content is much greater than downwelling.
The carbon content of the current upwelling waters is certainly higher than of the downwelling waters, because the deep oceans are enriched by sinking organic and inorganic carbonates from biolife at the surface. But there are no data which show that the total upwelling fluxes are greater than the downwelling fluxes, to the contrary: the overall average weighted flux is that the oceans are a net sink for CO2:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/mean.shtml
“This map yields an annual oceanic uptake flux for CO2 of 2.2 ± 0.4 GtC/yr”. Figures are for the reference year 1995. That includes as well as the ocean surface as the deep ocean upwelling/downwelling.
Then your notion that the enriched deep ocean waters are constantly increasing the atmosphere: as already explained to HenryP, that is only as long as the increase in the atmosphere is not reducing the inflows and outflows back to what it was before the temperature rise. 16 ppmv is enough to do that for a global area weighted 1°C temperature rise.
It doesn’t matter what the ancient CO2 level at the downwelling side was 800-1600 years ago. If it was (much) higher or (much) lower, the flux at the upwelling side would increase/decrease accordingly, the CO2 levels in the atmosphere would follow accordingly and at halve the ancient change in CO2 level (for which there is no proof), the in/out fluxes are again in equilibrium… Except if you expect that the ancient air was 200 ppmv higher than today and the upwelling of today changed with that amount in 160 years, without much smoothing during the 800-1600 years of transport… But even so, that has nothing to do with a current temperature effect.
Stephen Wilde says:
August 4, 2012 at 3:49 am
Simply put, if the absorption capacity of water falls as a result of warming then CO2 in the air will be blocked from entering the water as fast as would otherwise have been the case.
First the static case:
For a given temperature and salt content, there is a fixed ratio between pCO2(atm) and pCO2(aq), according to Henry’s Law.
If you increase the seawater temperature with 1°C, the pCO2(aq) increases with ~16 microatm. Thus releasing CO2 to the atmosphere until the atmosphere also increased with 16 microatm (~16 ppmv, a small difference is by water vapour content in air).
The real increase in temperature since the LIA is at maximum 1°C (depending of what reconstruction you prefer) thus may have caused an increase of 16 ppmv at maximum in the atmosphere. But we measure an increase of 100+ ppmv (70 ppmv since Mauna Loa). That not only proves that the oceans are not the cause of the increase, but also shows that the oceans did become a net sink for CO2, as the pCO2 of the atmosphere now is higher than of the oceans for the current temperature.
For the dynamic case:
Besides the seasonal changes, which are not of interest here (largely in equilibrium after a full cycle) and a limited uptake by the ocean surface waters, there is the continuous release of CO2 in the tropics, the continuous uptake of CO2 near the poles and the continuous exchange of these fluxes via the deep oceans and the atmosphere. Any disturbance in flows and/or content and/or temperature will result in a change of fluxes in/out the atmosphere and/or levels of CO2 in the atmosphere. But these are all limited in time for a limited change in one of these components: the moment that the CO2 level in the atmosphere is enough to increase/decrease the in/outfluxes back to equilibrium.
Furthermore Murry Salby doesn’t limit his findings to the ocean surface. He also introduces the soil moisture content across the globe. Warming over land during the day and in summer or during a general long term warming trend such as that from LIA to date being much greater than warming over oceans the CO2 response from warmer soil moisture would be larger than that from the oceans.
We have a quite reliable measurements of the total uptake for the whole biosphere, as well over land as in the oceans: the oxygen use. That shows that the biosphere as a whole is an increasing net sink for CO2. That includes bacterial breakdown of buried carbon in soils (as that also needs O2)… The increased pCO2 pressure in the atmosphere also pushes more CO2 into plant alveoles water, which results in increasing plant growth. The earth is greening…
It also perks up all the natural sources to cause a much bigger backing up within the system than just 16ppm.
The real temperature-CO2 ratio seems more restricted to 8 ppmv/°C, as the biosphere in general increases in uptake with higher temperatures, opposite to the oceans. Moreover, over longer periods of warming, the total bio area over land increases as land based ice sheets retreat and ice is replaced by tundra and tundra is replaced by forests…
“the biosphere in general increases in uptake (of CO2) with higher temperatures, opposite to the oceans”
I don’t think that is correct.So my question is as to how well we know the net global CO2 response of the entire biosphere to a rise in temperature of 1C.
I have in mind a scenario whereby the Earth’s surface is currently rather cold for biosphere activity as compared to the Carboniferous period.
Thus a bit more warmth makes a substantial difference to the entire biosphere (on land and in oceans) such that it ramps up a great deal in response to small temperature changes with a lot more CO2 pumped into the air during warmer spells as compared to cooler spells.
Photosynthesis burns oxygen and produces CO2 but only occurs when there is light.
When there is no light plants consume oxygen and release CO2 (respiration).
The balance between oxygen consumption and CO2 production depends on the amount of light:
http://www.bbc.co.uk/schools/ks3bitesize/science/organisms_behaviour_health/food_chains/revise4.shtml
Now long term the amount of light is pretty stable since TSI from the sun is largely constant but we all know that plants and ocean organisms grow more at a higher temperature because the amount of energy needed (from photosynthesis) per unit of growth is reduced.
So what happens if the temperature rises but the amount of light does not ?
The same amount of photosynthesis takes place but the amount of respiration increases due to the larger surface area of the larger or more numerous plants and ocean organisms.
A warmer temperature without more sunlight therefore increases CO2 production from respiration as compared to oxygen produced from photosynthesis.
So, maybe the warmer oceans do only add 16ppm of CO2 to the air per 1C temperature rise.
But how much extra CO2 is pumped into the atmosphere by plants and ocean organisms as a result of a 1C temperature rise in the absence of any additional light to fuel more photosynthesis ?
I think that figure would produce quite a surprise.
As a separate issue the figure of 16ppm per 1C in relation to the oceans might be inadequate anyway because soil moisture on the land masses would release CO2 upon being warmed which is another factor that you have not taken into account.
My guess is that the carbon cycle (and the amount of CO2 in the air) is much more responsive to small temperature changes than has hitherto been apreciated especially on centennial timescales such as MWP to LIA to date and the scale of that variability has for whatever reason not found its way into the ice core record.
Stomata data does show more variability than the ice cores but I suspect that even they do not reveal the full extent of natural CO2 variability in the atmosphere.
HenryP says:
August 4, 2012 at 4:35 am
Now, I am not sure if you have ever seen what happens with a storm over the sea,
but at the centre the pressure is so low that the water boils, thereby vaporising the water…
Having been a sailor (engine room) for a few years instead of (then obliged) military service, I never saw the waters boiling that way, but indeed heavy foaming at gail force 11…
To boil water at the center of a storm at 900 mbar, one still needs 90°C…
Natural warming also causes an increase in CO2. How much is that?
16 ppmv/°C, certainly not more, probably less because of increased sinks, if the other Henry’s Law still works as proven so many times…
Stephen Wilde says:
August 4, 2012 at 7:16 am
I have in mind a scenario whereby the Earth’s surface is currently rather cold for biosphere activity as compared to the Carboniferous period.
Agreed, but I you may agree that the higher temperatures during the Carboniferous and the higher CO2 levels caused an increase in uptake by the biosphere, which is what we are digging up and using today…
But how much extra CO2 is pumped into the atmosphere by plants and ocean organisms as a result of a 1C temperature rise in the absence of any additional light to fuel more photosynthesis ?
Higher temperatures and more CO2 do increase the CO2 uptake by plants, all other necessities, including sunlight, being equal. That is what is done in greenhouses: more CO2, more heat (and more light in many cases). But here are the real figures:
http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf
The oxygen use shows that the biosphere as a whole is a net sink for CO2. The measurements of the pCO2 differences and calculated fluxes over the oceans show that the oceans as a whole are a net sink for CO2. There is only one clear, continuous increasing source: the human emissions.
Ferdinand.
Thanks for your replies but you have not dealt with the main point.
TSI has remained much the same but the temperature has risen for other reasons.
If that happens, biosphere respiration involving production of CO2 increases relative to consumption of CO2 for the process of photosynthesis.
The paper you linked to said this:
“high atmospheric CO2 growth rates during most El Nino events are due to a
large land source”
Which confirms my proposal that higher temperatures without more sunlight will produce greater CO2 release from the biosphere because El Nino events warm the atmosphere without altering the amount of light available to fuel photosynthesis.
Given that temperatures have been increasing since the LIA without a large increase in raw TSI (the temperature rise having been a result of other aspects of solar variability) would that not explain why atmospheric CO2 has been rising without the need to invoke human emissions ?
The oceans are a net sink. They always are but the strength of that sink varies.
However the biosphere is not always a net sink.
When the globe is cooling then biosphere activity slows down despite TSI remaining approximately constant so that the biosphere becomes a net sink.Photosynthesis exceeds respiration.
When the globe is warming then biosphere activity speeds up despite TSI remaining approximately constant so that the biosphere becomes a net source. Respiration excedds photosynthesis.
So, MWP to LIA the biosphere progressively moves from source to sink. LIA to date the biosphere moves progressively from sink to source.
I think the current rise in CO2 is due to a combination of :
i) Reduced ocean absorption due to higher ocean temperatures.
ii) Increased biosphere release due to rising temperatures without an increase in light.
“The oxygen use shows that the biosphere as a whole is a net sink for CO2.”
Not necessarily.
All that is needed to account for recent observations is for respiration to increase relative to oxygen consumption so at a time of active sun one could have an increase in oxygen consumption but a greater increase in respiration because the effect of the higher temperature on growth rates is larger than the effect of more light on growth rates.
Stephen Wilde says:
August 4, 2012 at 8:41 am
All that is needed to account for recent observations is for respiration to increase relative to oxygen consumption so at a time of active sun one could have an increase in oxygen consumption but a greater increase in respiration
You can’t have it both:
At night, respiration of plants is high and CO2 is released, but that comes from the breakdown of carbohydrates and in general uses oxygen (it may do temporarely without oxygen, but that is like oxygen starved muscles under heavy use, not really good for you or the plants). During daytime, photosynthesis is at work, CO2 is incorporated into carbohydrates (and a lot of other stuff), releasing O2 at the same time. The overall balance since the 1990’s is that more oxygen is released and thus more CO2 is incorporated than reverse…
“The overall balance since the 1990′s is that more oxygen is released and thus more CO2 is incorporated than reverse…”
That doesn’t necessarily follow.
The active sun reduced global cloudiness which would allow more light to the surface hence an increase in oxygen production.
However the air temperature rose which has its own separate effect on plant growth.
All that is necessary to skew the balance in favour of CO2 production is for the effect on growth of the higher temperature to have a larger influence than the effect on growth of the higher light levels.
Can you demonstrate that that did not happen ?