The IPCC and the Carbon Cycle – Fact or Fantasy?
PERPETUAL DRAFT, 160901
We are told by the IPCC that CO2 emissions from burning fossil fuels are causing atmospheric
CO2 levels to rise and that these are causing global warming. Of the two links in this chain of
reasoning this article addresses the first. The IPCC position is stated in AR5 Chapter 6 (1) as:
The removal of human-emitted CO2 from the atmosphere by natural processes will take a few hundred thousand years (high confidence). Depending on the RCP scenario considered, about 15 to 40% of emitted CO2 will remain in the atmosphere longer than 1,000 years. This very long time required by sinks to remove anthropogenic CO2 makes climate change caused by elevated CO2 irreversible on human time scale. [original bold]
In this review I show that the IPCC view of the carbon cycle is fundamentally flawed in many
ways, and is not supportable at any meaningful level of confidence. This is not esoteric science to
be left to specialists or ‘great minds’. Any numerate person who cares to look and think can
understand the insignificance of our total industrial era CO2 emissions at less than 1% of the carbon
cycle and our annual emissions at just 5% of the air-sea fluxes.
The basis of the assumed causal link between our emissions and rising atmospheric CO2 has been that they have both risen over the last century or more. Plotted together, appropriately scaled and smoothed, it once looked plausible to me, but the price of fish and many other things have risen over that time, too. We need to look at the whole carbon cycle to put that relationship into perspective.
Figure 1 shows a summary of the IPCC version of the cycle. The unit PgC is petagrams of
carbon or billions of tons or gigatons. I use GtC. Arrows represent transfers, or fluxes, expressed in
PgC per year.
Figure 1: The Carbon Cycle - IPCC AR5 Fig. 6.1
Problems in the IPCC analysis of the cycle
Missing data: Marine biomass
The figure of 3 GtC for marine biota is wrong and seriously misleading. Moreover, it is not just an isolated error in a diagram. It is repeated in the adjacent text without attribution and implied elsewhere in the literature cited by the IPCC.
From note (b), the value of 3 GtC for marine biota seems to be a mislabelling in the IPCC reports and some of the surrounding literature, and based on satellite chlorophyl measurements which represent a highly dynamic photosynthetic sub-population of plankton (phytoplankton) at the base of the marine food chain – a small mass but with a high turnover as it is quickly consumed by other marine organisms.
I've collected together some references I found on marine biomass to give an idea of the state of the art. Total terrestrial bioactive carbon is taken from the diagram as 1,950+550 or 2,500 GtC.
1. IPCC (1), unattributed: 3 GtC [see (b) for discussion] – an instantaneous value
2. From various IPCC related sources (b): ‘marine biomass is 0.2% of total biomass’ implying about 5 GtC
3. Hansell et.al. (3), 2009: 662 GtC in DOM (Dissolved Organic Matter) is 200 times marine biomass, so implies 3.3 GtC
4. Hansell et.al. (3): Phytoplankton lifetimes are about 4-6 days. For 3 GtC and 5 day mean lifetime, total annual production = 5*365/5 = 365 GtC/y as a sink.
5. Whitman et.al. (4), Total ocean bacterial mass is 300 GtC – a partial component of the biota.
6. Census of Marine Life (5), 2010, ‘more than 90% of the biosphere’ = 2500*9 = 22,500 GtC
7. Arı´stegui et.al. (6): a ‘conservative’ estimate of deep ocean respiration of 20 GtC/y [old] to 33 GtC/y [theirs] – up to 3 times IPCC's 11 GtC/y for marine biota as a deep sink.
8. Massey (7): ‘Phytoplankton are believed to produce 80 percent of the organic material in the world.’ So scaling the terrestrial photosynthesis, 123*80/20 = 490 GtC/y as a sink.
9. EARTHSKY (8), 2015, ‘Estimates of the marine biota contribution to oxygen production vary from 50% [NASA, old] to 85%.’ This is linked to CO2 uptake in photosynthesis, so implies 123 to 700 GtC/y
10. My high school biology: marine life is the vast majority of biosphere, so at least 75% or 7,500 GtC.
From this we have 365,490 or up to 700 GtC/y for primary production. Pre-satellite estimates – e.g. 6 and 10 – were far higher than recent ones and little more than guesstimates, but phytoplankton blooms are most concentrated in nutrient rich coastal waters that are turbid, which make the satellite estimates unreliable, too. Bacteria alone may be 100 times the IPCC's 3 GtC figure, but it has been ignored. It is largely dormant but highly labile. Assuming a 1 day lifespan it has a potential productivity of 100,000 GtC/y.
Our emissions are in the order of 2% of marine primary production, which means that the IPCC is assuming that the marine ecosystem has been stable to within a fraction of a percent for a century or two. How stable has it been recently? A report (9) that plankton mass might have dropped by more than 10 to 40% in recent decades was criticised on the grounds of inadequate sampling – a criticism that can be made of all the measurements involved in the CO2 cycle. The authors reevaluated their results (10) and stuck to the qualitative result of an overall drop. Other research suggests large regional variations. In just six years, Gregg et.al. (11) measured an increase of 10% for chlorophyll in coastal waters, little change in open ocean, and reductions in mid-ocean gyres. Another report gave a sixfold increase in the Arabian sea.
Satellite imagery has shown a growth in the surface terrestrial biosphere of more than 10%, or 50 GtC, in recent decades. This has been attributed to increased atmospheric CO2 and temperatures. Over the industrial era it is likely to have increased by double this, absorbing around 100 GtC and far more if, as can be expected, soil life has also increased.
The growth and decay of plants and plankton follow complex dynamics that can vary on timescales of months to decades and millennia. Increased coastal runoff of nutrients, changing ocean currents and temperatures, overfishing, and other factors have had an impact on ocean life. We clearly have a poor grip on the assessment of marine biota, but it is a major labile reservoir.
Missing data: CO2 dissolved in oceans
The rate of exchange of CO2 between air and sea is determined by the solubility of CO2 in water
as described in note (d) – Henry's law – solubility decreases with increasing water temperature.
There is no evidence that solubility has decreased over the industrial era any more than Henry's law
would produce, and nothing but speculation to suggest it will decrease in the near future. Rather, if
we are at a climate millennial optimum (note g) future cooling will increase solubility.
A major role that the atmosphere plays in the cycle is carrying CO2 outgassed in warm equatorial waters poleward in the atmospheric circulation cells where it then dissolves in the cold polar seas. This part is a rapid process that runs on timescales of months to years rather than centuries to millennia.
The air-sea transfer of CO2 varies spatially and temporally and depends on surface temperatures and wind speeds in a highly nonlinear manner – i.e. a doubling of wind speed can increase solubility by a factor of 8 to 16 (12) as high winds create waves, spray, bubbles, and surface water turnover, but the details are poorly understood.
Across many areas of science and economics a mathematical error is commonly made in averaging values that are part of nonlinear systems. You can't. Wind speed is a good example of this as it varies greatly over short time periods and small distances. Averaging over time and space will tend to underestimate affects.
Figure 2: Winter mixing layer depth (13)
Figure 3 shows data accumulated by the Global Carbon Project. To put the human emissions into
perspective, if all fluxes were shown the full vertical scale would be 150 GtC/y. The IPCC classifies
the residual ‘other sinks’ as land sinks. The ‘land-use change emissions’ are only guesstimates of
the more politically prominent human induced changes, and their ‘ocean sink’ ignores biota.
I don't have confidence in this data, but it doesn't support the IPCC narrative. As our emissions
climb over the last 60 years, atmospheric growth starts to plateau around 1960 after a deep dip of
over 50% in the 1940s that doesn't match any comparable dip in the emissions. These are examples
of the lack of detailed correlation mentioned earlier.
Figure 3: Global Carbon Project historical CO2 fluxes from (15)
Other sinks (my addition) = emissions - atmospheric growth - ocean sink.
Missing data: Soils
The uncertainty range in soil carbon (1500 to 2400 GtC) is more than twice the total industrial era
human emissions. Zero change is assumed, but the real Green Revolution represented a shift in
agricultural practices from traditional ones that were geared to soil maintenance, to regimes based
on inorganic fertilisers. This has resulted in neglect of soil biomass and increased nutrient runoff to
the oceans, which is thought to have increased over the last century then stabilised in recent
decades. Human populations have increased as has the area of land used.
In AR5 6.1 the IPCC is frank:
… export of carbon from soils to rivers, burial of carbon in freshwater lakes and reservoirs and transport of carbon by rivers to the ocean are all assumed to be pre-industrial fluxes, that is, unchanged during 1750–2011. Some recent studies (Section 6.3) indicate that this assumption is likely not verified, but global estimates of the Industrial Era perturbation of all these fluxes was not available from peer-reviewed literature. ... Finally, processes that transport carbon at the surface (e.g., water and tillage erosion; Quinton et al., 2010) and human managements including fertilisation and irrigation (Gervois et al., 2008) are poorly or not represented at all [in models]. Broadly, models are still at their early stages in dealing with land use, land use change and forestry.
In the summary section below I discuss the observed recent increase in land biota, which will have had a positive impact on soil biomass.
Missing data: Volcanic emissions of CO2
The IPCC gives CO2 emissions from volcanos as 0.1 GtC/y. It has apparently based this on the assumption that volcanos are evenly distributed across the Earth's crust. Geologists disagree. The Earth's crust is much thinner under the oceans. Recent thinking is that the numbers of sea floor volcanos may be several orders of magnitude greater than assumed, and CO2 diffuses from a large surrounding area even when a volcano is otherwise inactive.
Casey (16) summarised the state of our understanding of volcanic emissions. He takes an estimate of 3,500,000 submarine volcanos (17) and, assuming 4% of these as active, calculates possible emissions of 120 GtC/y. He gives a conservative minimum of 24 GtC/y. My reading of his analysis is that his high figure is already conservative because he is knowingly leaving out diffusion from around the inactive volcanos. Either way, these figures dwarf our 9 GtC/y making it quite irrelevant. They also imply the existence of unaccounted rapid sink capacity 3 to 10 times larger than our annual emissions.
Meaningless data: Isotopic analysis
One line of reasoning meant to show that much of the increased atmospheric CO2 must be anthropogenic is based on carbon isotope ratios. Most photosynthesis preferentially selects 12C over 13C and the isotope ratios in the atmosphere suggest a partial contribution from organic origins or fossil fuels (old plant material).
Segalstad (18) says,
The isotopic mass balance calculations show that at least 96% of the current atmospheric CO2 is isotopically indistinguishable from non-fossil-fuel sources, i.e. natural marine and juvenile sources from the Earth's interior.
and from Coe (19),
Far from being a fingerprint for anthropogenic sources of CO2, the isotopic ratio variation suggests conversely that the main source of CO2 is NOT in fact retained anthropogenic emissions.
Additionally, the isotopic analysis ignores the impact of photosynthesis in phytoplankton and assumes a constant pre-industrial past. It also ignores volcanos as a source. Casey provides many journal references confirming that volcanic CO2 emissions can also be 13C depleted, so can't be isotopically distinguished from fossil fuels. There is no isotope ‘signature’ pointing to anthropogenic fossil fuel use.
Corrupted data: The artificial balancing act
One obvious artefact in the IPCC carbon fluxes is that they balance to 0.1 GtC/y – i.e. to within 0.05% for air – from data that is at best 10% accurate. The figures have been adjusted to balance. The most obvious, and openly admitted, example of this is assuming the whole air to land flux is the remainder of the others – the ‘other sinks’ data added to Figure 3.
The rest is more subtle. The net atmospheric sink has been estimated using a combination of carbon isotope analysis and the slight reduction measured in atmospheric oxygen, both of which suffer from the problems of ignoring marine biota and assuming a fixed past. The fluxes have been made up to fit this net value.
In financial accounting, every cent is countable and a strict balance is a desirable goal. Here we are dealing with science and engineering where even countable values are rarely precisely known. Things never add up exactly. Mining geologists would end up in prison for such deception.
Meaningless analysis: Models
The IPCC bases its analysis on model outputs. This issue is touched on in note (e). With models as complex as needed for the carbon cycle, all we can expect are hints not solutions. With sparse current data, historical data missing, and our poor understanding of real world mechanisms, all we can expect is a reflection of the modellers' expectations.
As admitted in the literature and elsewhere, confidence in the models has been built up through a cyclic process of consensus building over decades of annual conferences, and publications with mutually reenforcing peer review. In science, confidence comes from the alignment of theories and models with real world data. If we don't have the data we suspend belief until we do.
Ignored Data: Ice cores
I have doubts about the relibility of measurements of past temperature and CO2 levels based on air trapped in ice cores, but since the IPCC and retinue use them when it suits them it's reasonable to point out that long term data shown, for example, in Figure 4 starkly contradict their whole CO2 scare narative. We see CO2 levels 2 to 5 times recent levels between 70 to 250 My ago and 7 to 17 times higher between 390 and 550 My ago. Over this whole time period, temperatures are clearly regulated by the water thermostat I discuss in Energy and Atmosphere (25), which limits surface temperatures to below 30 Cº.
Figure 4: Ice core measurements for past CO2 and atmospheric temperatures.
The two scenarios for phytoplankton primary production (50% and 80% of biosphere total)
provide a plausible range that illustrates the high sensitivity of the cycle to this parameter. The
alignment of the 50% respiration figure with measurements (r46, r45) provides some support for
this lower value.
Table 1: Human emissions of CO2 as % of cycle reservoirs and fluxes.
We don't need CO2 removed from the sea, or for us to stop adding it. Our whole industrial era
contribution is insignificant. We don't need to get CO2 out of the atmosphere, either, and shouldn't
want to, but that's another issue.
Table 2: A summary of natural constraints
Fact or Fantasy – A Review:
Most facts are fragile mercurial creatures – often spotted in the distance flitting about in thickets of data, but rarely captured for close examination when they usually collapse into a small pile of pixy dust. As a writer of Near Future Fiction who tries to keep to the Hard SciFi genre rather than veer too far into Fantasy I often find myself confronted with the distinction. I'm generous with myself in these judgements, so I'm obliged to apply the same standards to others when I believe they are acting in good faith.
The simplest approach is to forget about fact and concentrate on plausibility – how well does an idea conform to what we believe we know about the universe – the probable to the possible. How much tends to support an idea and how much tends to undermine it. When all we know, however little, undermines the idea, we have crossed a boundary into Fantasy.
All nontrivial attempts to portray the future are Future Fiction. With the IPCC's attempts, the fact
that our emissions are lost in the noise still leaves their narrative plausible, though wildly
overstated, but their assumption that the planet's physical systems and ecologies have been minutely
stable for millennia contradicts all the extensive historical evidence we have.
I can excuse small excursions into fantasy if they're not essential to the plot, but this is not a fringe assumption it's the foundation stone of their plot, so I'm bound to see their work as Fantasy. But, as they and Al Gore have demonstrated, it's a very popular genre, particularly when it has a strong apocalyptic theme.
The reliability of data is particularly important if we are to take trillion dollar carbon markets or carbon taxes seriously. The gold standard was used for currency because the reserves were controlled and assay was accurate. The reverse is true for the carbon cycle. Little of the data we have is reliably known. For carbon accounting, an overall estimate of ±20% has been mentioned in the literature. The output of the models used by the Global Carbon Project disagree by this amount. I delved into a few references for the marine data, and the most detailed used the instrument error of the readings. This ignores the fact that the reservoirs and fluxes are aggregates of heterogeneous data that is geographically sparse and scattered over time, so the actual uncertainty was unknown.
The IPCC fallback for error estimates is to ask a few of their mutually self anointed experts to guess. All that can be guessed here is that most of the values in the above diagram are more accurately known than their value for marine biomass.
b. Marine biota
The value of 3 GtC for marine biota is unattributed in AR5 and referred to as ‘phytoplankton and other microorganisms’. I tried to find an original source in nearby citations. The value seems to have been for phytoplankton only and generated from models estimating ocean chlorophyll from satellite data then calculating Net Primary Production. In this branch of the literature I found repeated references to the figure for marine biomass of 0.2% of total biomass, with circular attribution and no original source. This implies a marine biomass of 5 GtC.
It's a current or instantaneous value for a biomass. Hansell et.al. (3) give a turnover cycle of 4 to 6 days with a possible extreme of two weeks mentioned. Taking 5 GtC and a lifetime of 5 days, over a full year the total production would be 365 GtC/y.
Munshi (20) found that the correlations between our emissions and atmospheric CO2 change were R2 = 0.45 and R2 = 0.0068 for raw and detrended data respectively. This means the correlation is only in the trends, as can be seen in Figure 3. The correlations between atmospheric CO2 change and surface temperatures were R2 = 0.56 and R2 = 0.45 for raw and detrended, so atmospheric CO2 varies with temperature as we expect from solubility laws.
d. The solubility of CO2
For pure water, this is well understood and its temperature dependence is given by Henry's law – relatively uncontroversial physics. Increased atmospheric concentration pushes CO2 into the water surface. Higher water temperatures push it out – as we see when a can of carbonated drink is opened after sitting in the sun. But the oceans aren't pure water. It is claimed (21) that IPCC have reinvented the laws of physics to reduce the ocean sink. If carbonated drinks behaved as the IPCC thinks they should, they'd be flat.
The IPCC retinue focus on the inorganic chemistry that takes place after CO2 is dissolved – the Reville Factor. I looked for the scientific basis for this approach and found only theory and no reference to experiment. The soft drink companies must have researched this extensively over the years and gone beyond inorganic chemistry with the inclusion of fruit juices. The oceans go further with complex ecological dynamics.
Egleston et. al. (22) admit that the Revelle factor of the oceans hasn't changed much over the industrial era, but add to the speculation that it might in the future, causing the oceans to take up CO2 less readily. Some simple laboratory work might clarify this, but New Age Climate Science seems to have an aversion to experimentation, preferring supercomputer models and globetrotting fieldwork. The Argo buoys are now automating ocean survey, so we may eventually have a detailed and coherent physical view of the oceans. As can be seen from my discussion of marine biota, a full picture is a long way off.
Models underly almost everything the IPCC says – layers of model upon model. I've built a few mathematical models over the years – simple models that have complex through to chaotic behaviour, and complicated models with many parameters or dimensions. The amount of data needed goes up with power of the number of dimensions. This is easy to understand. If you take 10 samples along a line you need 100 samples over a square and 1000 through a cube to sustain the sampling density. IPCC models have hundreds of parameters, so with scarce and unreliable data the modellers are lost.
Scattered through the IPCC literature base are many pleas for more and better data. They have my sympathy there, but they lose it by not insisting that the data limitations and uncertainties in model structures that reflect our poor understanding of real world mechanisms are not reflected in the IPCC rhetoric.
I've had a lifelong interest in soils, starting with my first few years living in a house built on a sand dune by a beach. One of my earliest memories was discovering clay – amazed that it didn't run through my fingers. Then came maintaining the garden of a newly built family home from an early age. Below a shallow surface layer it was sterile clay that had a faint musty smell when dug deep, as though it hadn't breathed fresh air for a million years. The ornamental Australian natives out the front coped well enough, but the lawns, fruit trees, and vegetable gardens struggled. Someone commented on the problem of soils being poor in the newly developing suburb. An understanding of what good soil was like came when the government dumped a truckload of rich dark loam outside every home in the suburb. It had realised that creating a lake over the flats of the river that ran through the centre of the city was going to drown the best expanse of fertile soil in the district.
I later helped a friend build a farm-scale composting process in his effort to revive some badly worked-out land to start a small market garden. I remember seeing one of the huge chainsaw hewn bins, early in the morning in a beautiful creek-side glade, jetting mist from the crowbar holes that ventilated it.
A neighbour, an old man who had grown up in the district, described how in his youth it had been highly productive dairy country with deep rich soils, but by then much of the land had turned to poor scrub with patches of sand in places or, at best, supporting a few beef cattle. He inspired me to plough through F.E. Allison's massive tome on soil organic matter (23) – starting with geology, through a multitude of microbes and fungi, and, as I recall, finishing with larger creatures like worms and insects.
Eventually, with a backyard of my own and starting with the same clay as my parents' home, I've spent the last few decades building it up. When I'm gone it will probably be excavated to provide a basement car park for a block of apartments, but it's been an interesting and educational experience for myself and others. Humans are already using most of the viable agricultural land on the planet and generally degrading it. In the past, vast areas of rich agricultural land supporting whole civilisations have been turned to desert, or near desert, when climate optima have ended. Where the soils have been destroyed – most of the Middle East, North Africa and across the north of the Mediterranean, parts of India and China – there sometimes remained what Carter and Dale (24) refer to as ‘rained-on deserts’ – regions that have water but not the soils that can capture and hold it. The challenge for this century is to replace quantity with quality, and to do it voluntarily and productively rather than let it happen by destructive default.
g. Natural cycles
Ocean currents have quasi-millennial timing of around 800 to 1000 years. Along with climate optima, they are probably best seen as geographical events that are influenced by weak external drivers that have a more regular cyclic pattern. My small excursion into climate modelling consisted of looking at published models of sunspot cycles and adjusting them to fit surface temperature data for the southern oceans – initially, a few hours work with a spreadsheet. The accuracy and simplicity of the result spurred me on to explore further. The model already fitted the data far better than the supercomputer models used by the IPCC.
The model has been extrapolated to show the last millennial peak, the Little Ice Age, and future trends. Atmospheric CO2 levels can be expected to follow a similar cycle as it outgasses in warmer climes and is more readily absorbed as the water cools. (25)
1. IPCC, WG1AR5_Chapter06_FINAL
2. Munshi, Jamal, 2015, Uncertain flow accounting and the IPCC carbon budget: A Note, http:// papers.ssrn.com/sol3/papers.cfm?abstract_id=2654191
3. Hansell et.al., 2009, Dissolved Organic Matter in the Ocean, http://dx.doi.org/10.5670/oceanog. 2009.109
4. Whitman et.al., 1998, Prokaryotes: The unseen majority, PNAS, Vol. 95, pp. 6578–6583
5. Census of Marine Life, 2010, The Census and Ocean Observing Systems
6. Arı´stegui, Javier et.al., 2003, Respiration in the dark ocean, Geophysical Research Letters, Vol. 30, No. 2, 1041
7. Massie, Frederick, editor, 1998, The Uncommon Guide to Common Life of Narragansett Bay
8. EARTHSKY, JUN 08, 2015, How much do oceans add to world’s oxygen?
9. Boyce et.al., 2010, Nature 466, 591–596: Global phytoplankton decline over the past century
10. Boyce D.G. et.al., 2014, Estimating global chlorophyll changes over the past century, Progress In Oceanography 122, 163-173
11. Gregg et.al., 2005, Recent trends in global ocean chlorophyll, Geophysical Research Letters, Volume 32, Issue 3, February 2005
12. Wanninkhof and McGillis, A cubic relationship between air-sea CO2 exchange and wind speed, Geographical Research Letters, V26 #13, 1999
13. Wikipedia: mixed layer depth
14. Beck, Ernst-Georg, 2007, 180 Years Of Atmospheric Co2 Gas Analysis By Chemical Methods, Energy & Environment, 18 #2
15. Global Carbon Project, ‘The Global Carbon Budget 2014 is a collaborative effort of the global carbon cycle science community coordinated by the Global Carbon Project.’
16. Casey, Timothy; 2009: http://carbon-budget.geologist-1011.net, Volcanic Carbon Dioxide
17. Hillier, J. K., & Watts, A. B., 2007, Global distribution of seamounts from ship-track bathymetry
data, Geophysical. Research. Letters, Vol. 34
18. Segalstad, Tom V., 1998, The distribution of CO2 between atmosphere, hydrosphere, and lithosphere, The Report of the European Science and Environment Forum, 288 pp
19. Coe, David, 2013, Atmospheric Carbon Dioxide Control Mechanisms - Part 1
20. Munshi, Jamal; 2015, Responsiveness of atmospheric CO2 to anthropogenic emissions: a note, http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2642639
21. Segalstad, Tom V., 1998, Carbon cycle modelling and the residence time of natural and anthropogenic atmospheric CO2, The Report of the European Science and Environment Forum
22. Egleston, Eric S. et.al., 2010, Revelle revisited: Buffer factors that quantify the response of ocean chemistry to changes in DIC and alkalinity, Global Biogeochemical Cycles, V24 #1
23. Allison, F.E., 1973, Soil organic matter and its role in crop production, Elsevier Science.
24. Carter, V.G. and Dale, T., Topsoil and Civilization, University of Oklahoma Press, 1955, 1974.
25. Davies, Dai, brindabella.id.au/ClimArc