Guest post by David Middleton
Graphic: The relentless rise of carbon dioxide
Ancient air bubbles trapped in ice enable us to step back in time and see what Earth’s atmosphere, and climate, were like in the distant past. They tell us that levels of carbon dioxide (CO2) in the atmosphere are higher than they have been at any time in the past 400,000 years. During ice ages, CO2 levels were around 200 parts per million (ppm), and during the warmer interglacial periods, they hovered around 280 ppm (see fluctuations in the graph). In 2013, CO2 levels surpassed 400 ppm for the first time in recorded history. This recent relentless rise in CO2 shows a remarkably constant relationship with fossil-fuel burning, and can be well accounted for based on the simple premise that about 60 percent of fossil-fuel emissions stay in the air.
Today, we stand on the threshold of a new geologic era, which some term the “Anthropocene”, one where the climate is very different to the one our ancestors knew.
[…Blah, blah, blah…]
We’ve all heard variations of this meme… ad nauseum… They tell us that levels of carbon dioxide (CO2) in the atmosphere are higher than they have been at any time in the past 400,000 800,000 2.5 million 20 million years.
This claim is generally based on the fact that Antarctic ice cores don’t indicate interglacial CO2 levels above 280-300 ppm at any point in the past 800,000 years or so. While this is true, does it actually inform us that atmospheric CO2 levels could not have been well over 300 ppm during pre-industrial times?
WAIS Divide and the Effects of Resolution on Amplitude
West Antarctic Ice Sheet Divide Ice Core
On December 1, 2011, the West Antarctic Ice Sheet (WAIS) Divide ice core project, funded by the National Science Foundation, reached its final depth of 3405 meters (11,171 feet; over 2 miles), recovering the longest U.S. ice core to date from the polar regions. The 12.2-centimeter (4.8-inch) diameter cylinders of ice that make up the ice core contain uniquely detailed information on past environmental conditions during the last 68,000 years, such as the atmospheric concentration of greenhouse gases, surface air temperature, wind patterns, the extent of sea ice around Antarctica, and the average temperature of the ocean. Successfully retrieving the ice core is the culmination of an eight-year project to obtain a paleoclimate record from one of the remotest parts of the Antarctic continent.
[…]
In the WAIS Divide ice core, each of the past 30,000 years of snowfall can be identified in individual layers of ice, with lower temporal resolution records extending to 68,000 years before present. By allowing an examination of past climate at an annual resolution, the ice core record is helping scientists understand why climate can change abruptly and how climate may unfold in the coming century.
Other ice-coring projects have produced cores of lower temporal resolution, showing that the current level of atmospheric greenhouse gases, which is due to the burning of fossil fuels, is the highest in at least 800,000 years. The ice from the WAIS Divide ice core that is between 30,000 and 68,000 years old — while not containing records with annual resolution — contains a higher time resolution record than previous projects.
[…]
This comment caught my attention:
Other ice-coring projects have produced cores of lower temporal resolution, showing that the current level of atmospheric greenhouse gases, which is due to the burning of fossil fuels, is the highest in at least 800,000 years.
This raises the question: Are the ice cores “of lower temporal resolution” capable of resolving century-scale shifts in atmospheric CO2? If not, then the conclusion “that the current level of atmospheric greenhouse gases, which is due to the burning of fossil fuels, is the highest in at least 800,000 years” is not supported.
The ice cores cannot resolve CO2 shifts that occur over periods of time shorter than twice the bubble enclosure period.
According to Neftel et al. (1988), CO2 fluctuation with a duration of less than twice the bubble enclosure time (equivalent to approximately 134 calendar yr in the case of Byrd ice and up to 550 calendar yr in Dome Concordia) cannot be detected in the ice or reconstructed by deconvolution.
McElwain et al., 2001
Here is a schematic diagram of bubble trapping process for the DE08 ice core:
The DE08 core has a resolution at least as fine as 30 years, possibly as fine as 10 years.
Ahn et al., 2012 compared the resolutions of the WAIS Divide, Law Dome DE08 and Dronning Maud Land ice cores over the past 1,000 years and, unsurprisingly, found that the highest resolution core (DE08) had the highest amplitude range and resolved a sharp, short-duration drop in atmospheric CO2 during the nadir of the Little Ice Age (ca. 1610 AD).
The stabilization of atmospheric CO2 concentration during the 1940s and 1950s is a notable feature in the ice core record. The new high density measurements confirm this result and show that CO2 concentrations stabilized at 310–312 ppm from ~1940–1955. The CH4 and N2O growth rates also decreased during this period, although the N2O variation is comparable to the measurement uncertainty. Smoothing due to enclosure of air in the ice (about 10 years at DE08) removes high frequency variations from the record, so the true atmospheric variation may have been larger than represented in the ice core air record. Even a decrease in the atmospheric CO2 concentration during the mid-1940s is consistent with the Law Dome record and the air enclosure smoothing, suggesting a large additional sink of ~3.0 PgC yr-1 [Trudinger et al., 2002a]. The d13CO2 record during this time suggests that this additional sink was mostly oceanic and not caused by lower fossil emissions or the terrestrial biosphere [Etheridge et al., 1996; Trudinger et al., 2002a]. The processes that could cause this response are still unknown.
[11] The CO2 stabilization occurred during a shift from persistent El Niño to La Niña conditions [Allan and D’Arrigo, 1999]. This coincided with a warm-cool phase change of the Pacific Decadal Oscillation [Mantua et al., 1997], cooling temperatures [Moberg et al., 2005] and progressively weakening North Atlantic thermohaline circulation [Latif et al., 2004]. The combined effect of these factors on the trace gas budgets is not presently well understood. They may be significant for the atmospheric CO2 concentration if fluxes in areas of carbon uptake, such as the North Pacific Ocean, are enhanced, or if efflux from the tropics is suppressed.
MacFarling Meure et al., 2006
From about 1940 through 1955, approximately 24 billion tons of carbon went straight from the exhaust pipes into the oceans and/or biosphere:
Ahn et al., 2012 constructed a series of synthetic ice cores of varying resolution to mostly explain the difference between the DE08 and WAIS Divide cores in resolving the LIA CO2 plunge ca. 1610 AD:
There is a fundamental relationship between frequency and amplitude. If you apply a low pass filter or smoothing average to a time series, you attenuate the amplitude response:
Breaking a Perfectly Good Hockey Stick
I downloaded a composite ice core CO2 record (0-800 kyr BP) from Bereiter et al. (2014) and generated the standard CO2 Hockey Stick:
This is a composite of the following ice cores:
| -51-1800 yr BP:’ | Law Dome (Rubino et al., 2013) |
| 1.8-2 kyr BP: | Law Dome (MacFarling Meure et al., 2006) |
| 2-11 kyr BP: | Dome C (Monnin et al., 2001 + 2004) |
| 11-22 kyr BP: | WAIS (Marcott et al., 2014) minus 4 ppmv (see text) |
| 22-40 kyr BP: | Siple Dome (Ahn et al., 2014) |
| 40-60 kyr BP: | TALDICE (Bereiter et al., 2012) |
| 60-115 kyr BP: | EDML (Bereiter et al., 2012) |
| 105-155 kyr BP: | Dome C Sublimation (Schneider et al., 2013) |
| 155-393 kyr BP: | Vostok (Petit et al., 1999) |
| 393-611 kyr BP: | Dome C (Siegenthaler et al., 2005) |
| 612-800 kyr BP: | Dome C (Bereiter et al., 2014) |
These ice cores are of vastly different resolutions. Petit et al., 1999 indicate that the CO2 resolution for Vostok is 1,500 years. Lüthi et al., 2008 suggest a CO2 resolution of about 500 years for Dome C. It appears that the high resolution Law Dome DE08 core was just spliced on to the lower frequency older ice cores.
If I apply smoothing filters to the DE08 ice core in order to match the resolution of the lower resolution ice cores, I get a considerably different picture.
Using the information in Table 1 from Ahn et al., 2012:
| Ice Core Name | Mean Temp. (°C) | Acc. Rate (cm we/yr) | Ice-Gas Age Diff. (yr) | Gas Age Distribution (yr) | Reference for Gas Age Distribution |
|---|---|---|---|---|---|
| Dronning Maud Land | –44.6 | 6.4 | 835 | 59 ± 5 | Siegenthaler et al. [2005] |
| DE-08 (Law Dome) | –19 | 110 | 31 | 10 | Trudinger [2000] |
| DSS (Law Dome) | –22 | 60 | 58 | 14 | Trudinger [2000] |
| WDC05A (WAIS Divide) | –31 | 22 | 205 | ≥30? | this study |
I plotted the relationship between Ice-Gas Age Difference and Gas Age Distribution and used this to calculate a gas age distribution for the Holocene portion Vostok core:
The application of a 130-yr smoothing filter to the DE08 core yields a Hockey Stick with a seriously shortened blade:
If I use a 500-yr smoothing filter, the Hockey Stick loses its blade completely:
I didn’t even try to use the instrumental record, because it would be a single data point at the same resolution as the Vostok and EPICA Dome C ice cores.
Conclusion
The lower frequency ice cores are not capable of resolving century scale CO2 shifts. As such, they cannot be used to rule out the possibility of short duration fluctuations comparable to the industrial era rise in atmospheric CO2 during the early Holocene and Pleistocene. And thus do not contradict the conclusions of Wagner et al., 1999:
In contrast to conventional ice core estimates of 270 to 280 parts per million by volume (ppmv), the stomatal frequency signal suggests that early Holocene carbon dioxide concentrations were well above 300 ppmv.
[…]
Most of the Holocene ice core records from Antarctica do not have adequate temporal resolution.
[…]
Our results falsify the concept of relatively stabilized Holocene CO2 concentrations of 270 to 280 ppmv until the industrial revolution. SI-based CO2 reconstructions may even suggest that, during the early Holocene, atmospheric CO2 concentrations that were 300 ppmv could have been the rule rather than the exception.
Or Wagner et al., 2004:
The majority of the stomatal frequency-based estimates of CO 2 for the Holocene do not support the widely accepted concept of comparably stable CO2 concentrations throughout the past 11,500 years. To address the critique that these stomatal frequency variations result from local environmental change or methodological insufficiencies, multiple stomatal frequency records were compared for three climatic key periods during the Holocene, namely the Preboreal oscillation, the 8.2 kyr cooling event and the Little Ice Age. The highly comparable fluctuations in the paleo-atmospheric CO2 records, which were obtained from different continents and plant species (deciduous angiosperms as well as conifers) using varying calibration approaches, provide strong evidence for the integrity of leaf-based CO2 quantification.
References
Ahn, J., E. J. Brook, L. Mitchell, J. Rosen, J. R. McConnell, K. Taylor, D. Etheridge, and M. Rubino (2012), Atmospheric CO2 over the last 1000 years: A high-resolution record from the West Antarctic Ice Sheet (WAIS) Divide ice core, Global Biogeochem. Cycles, 26, GB2027, doi:10.1029/2011GB004247. LINK
Bereiter, Bernhard. Sarah Eggleston, Jochen Schmitt, Christoph Nehrbass-Ahles, Thomas F. Stocker, Hubertus Fischer, Sepp Kipfstuhl and Jerome Chappellaz. 2015. Revision of the EPICA Dome C CO2 record from 800 to 600 kyr before present. Geophysical Research Letters. . doi: 10.1002/2014GL061957. LINK
Bereiter et al. (2014), Revision of the EPICA Dome C CO2 record from 800 to 600 kyr before present, Geophysical Research Letters, doi: 10.1002/2014GL061957. Data
Lüthi, D., M. Le Floch, B. Bereiter, T. Blunier, J.-M. Barnola, U. Siegenthaler, D. Raynaud, J. Jouzel, H. Fischer, K. Kawamura, and T. F. Stocker. 2008. High-resolution carbon dioxide concentration record 650,000-800,000 years before present. Nature 453(7193):379-382, doi: 10.1038/nature06949. LINK
MacFarling Meure, C., D. Etheridge, C. Trudinger, P. Steele, R. Langenfelds, T. van Ommen, A. Smith, and J. Elkins. 2006. The Law Dome CO2, CH4 and N2O Ice Core Records Extended to 2000 years BP. Geophysical Research Letters, Vol. 33, No. 14, L14810 10.1029/2006GL026152. LINK Data
McElwain et al., 2001. Stomatal evidence for a decline in atmospheric CO2 concentration during the Younger Dryas stadial: a comparison with Antarctic ice core records. J. Quaternary Sci., Vol. 17 pp. 21–29. ISSN 0267-8179. LINK
Petit J.R., Jouzel J., Raynaud D., Barkov N.I., Barnola J.M., Basile I., Bender M., Chappellaz J., Davis J., Delaygue G., Delmotte M., Kotlyakov V.M., Legrand M., Lipenkov V., Lorius C.,
Pépin L., Ritz C., Saltzman E., Stievenard M., 1999, Climate and Atmospheric History of the Past 420,000 years from the Vostok Ice Core, Antarctica, Nature, 399, pp.429-436. LINK
Petit, J.R., et al., 2001, Vostok Ice Core Data for 420,000 Years, IGBP PAGES/World Data Center
for Paleoclimatology Data Contribution Series #2001-076. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. LINK
Wagner F, et al., 1999. Century-scale shifts in Early Holocene CO2 concentration. Science 284:1971–1973.
Wagner F, Kouwenberg LLR, van Hoof TB, Visscher H, 2004. Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency. Quat Sci Rev 23:1947–1954. LINK
Further Reading
Fischer, H. A Short Primer on Ice Core Science. Climate and Environmental Physics, Physics Institute, University of Bern. LINK
As far as the hockey stick thing is concerned I find it suspicious but then again, I looked at the calendar and it is the run to the Stanley Cup :). ( And of course it is also “March Madness”). And hey NBA is ready for a slam dunk and the MLB is in “Spring Training”. Have fun everyone.
I would bet that baseball was the “gateway drug” for most of us climate data fanatics… 😉
I don’t think you are far of , must have started with bubble gum cards :).
Thank you David,
It has been said many times over the years that one cannot draw short term inferences from poor resolution ice core data. This is intuitively, common sensical, qualiatively so.
Your work here is a valuable, even strikingly visual, quantitative support for this. Researchers who blithely press ahead with invalid comparisons should have this data burned into their brains.
It is shameful that poor quality science has been produced by the activists responsible. They should at least have expressed formal confidence limits on their data. Misuse, or no use, of formal error estimation is rampant in climate work. If it was routinely used correctly, many of these hockey stick type wrong statements would have been headed off at the pass.
Geoff
I had not realized that Antarctica is the most amazing Continent there is!
A continent that never experiences severe or multi-year droughts,
• Never experiences heavy rain or flooding,
• Always has summer melt,
• Never suffers from excessive summer melt,
• Where ice melt does not drain down, filling voids then freezing,
• Where frozen melt or rain does not form excluded gas bubbles,
• Where the ice always settles and sits in one spot,
• Where laminar ice flow does not occur,
• Where compression does not cause ice to thin via sideways flow,
• Where the ice is never stripped of snow by wind,
• Where drifts never form,
• Where avalanches and snow slumps never occur,
• Where subsurface terrain never causes ice flows to merge.
Apparently, Antarctica is a land where norm thrives under perpetual daily, seasonal, annual, decade conditions.
Imagine that?
http://lgge.osug.fr/IMG/fparrenin/courses/2013-2014/2013-10-10-M2RTUE-IceSheetAge.pdf
Pages 18 & 25
• Always has summer melt,
• Never suffers from excessive summer melt,
Please post max “summer temps” for Antarctica !
• Where avalanches and snow slumps never occur,
Law Dome , Gomez Dome, Dome C …. see any kind of picture forming? Ice cores are usually taken from the local highpoint in the terrain where snow and ice can accumulate but don’t be covered by slumps and avalanches and are not disturbed by sideways creep.
Ease up on the heavy sarcasm and do a little reading.
The high point is what people think/believe is the highpoint.
While it is possible, it is not viable to believe the high point, an ice high point no less, has been the highest point forever.
Nor can “max” high temps be posted for all Antarctic history. Claims for ionized atoms/molecules measurements under the Southern ozone hole also concern me.
A high point is where sideways creep is greatest.
Yes, the presentation is well done, and very interesting.
What was that about reading?
In any real world industrial/commercial/architecture/flight/oceanic/etc design, the design tem utilizes test engineers to identify and list every possible concern/effect/external and internal influence/physics/weather/storm/geological impacts.
For major financial programs there is a similar effort to identify every possible datum/input/mistype/calculation/bit size/data transfer/data storage/data retrieval/etc.
Both systems require honest attempts predetermine every possible fault, before development. As design/development proceeds, more concerns will be added to the test process.
Running a classic input test deck is just one flavor of one concerns.
Without constructing a proper test design and process, assumptions, single focus desires, simple process and output expectations, whatever, going into a study skews every output according to researcher perception and expectation.
Thanks for the link, very interesting presentation.
David Middleton March 28, 2017 at 4:20 pm
I’m actually a fan of dendroclimatology. I’ll take an Esper treemometer over a Mannian thermometer any day of the week.
https://wattsupwiththat.com/2008/06/13/surprise-leaves-maintain-temperature-new-findings-may-put-dendroclimatology-as-metric-of-past-temperature-into-question/
Point #1: Don’t you have to prove CO2 can even cause climate change? Historical records seem to prove CO2 hasn’t been a cause of any of the pre-industrial climate changes. Why the focus on CO2 anyway? We haven’t had extreme climate variations during the industrial age.
Climate Changed Caused the Pre-Industrial Bronze Age Collapse
https://co2islife.wordpress.com/2017/03/29/climate-changed-caused-the-pre-industrial-bronze-age-collapse/
Point #2: Why the lack of focus on stomatal frequency? That seem a more reasonable method than CO2.
Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency analysis
https://dspace.library.uu.nl/handle/1874/20766
http://i90.photobucket.com/albums/k247/dhm1353/Climate%20Change/LawDomeMLOKouwenbergBeck1800.png
That looks like my handiwork.
It’s from my first WUWT post… https://wattsupwiththat.com/2010/12/26/co2-ice-cores-vs-plant-stomata/
Thanks, be sure to share or repost. You must do good work…LOL.
Using the information in Table 1 from Ahn et al., 2012:
Acc. Rate (cm we/yr)
Dronning Maud Land 6.4
DE-08 (Law Dome) 110
DSS (Law Dome) 60
WDC05A (WAIS Divide) 22
Given that most of the speculations I’ve seen suggest that over the last million years there has been virtually no opportunity for any significant melting of the Antarctic ice sheets at all, even these feeble rates of annual accumulation would have resulted in an ice sheet from 35 miles to 500+ miles thick if the ice wasn’t disappearing by some other means. My preferred alternate would be that as the ice reaches a critical height a compressive limit is passed and the ice is extruded out to the ocean. The trouble with this speculation is that it makes it a hard case to support the notion that the ice is able to maintain a precise vertical record while hundreds of miles of ice is moving in, down, and out of the ice sheet.
It “disappears” from the bottom.
This is why domes are the preferred locations for core drilling…
https://lima.nasa.gov/antarctica/
ad nauseum?
Technical comment:
The NASA webpage quoted above is here https://climate.nasa.gov/climate_resources/24/
It clearly states 60 % of emissions stay in the atmosphere. However, I believe this figure should be between 40 and 50 %, and most likely it’s closer to 40 %, say 43-44%. Would somebody comment on this specific point. I have this figure coded in the spreadsheet I use to estimate CO2 concentration as a function of different burn rates for oil, heavy oil, gas, natural gas liquids, and coal. This is what I use to estimate a peak co2 concentration around 630 ppm, and I need to make sure the fraction that stays over time isn’t 60 % as stated by the NASA webpage. Thanks.
Fernando, the airborne fraction (% of emissions that stay in the atmosphere) is variable, and has been going down with time. It is now about 44%. Not only emissions, but also land uses influence this fraction, and apparently changes in land uses are behind the latest changes.
http://csas.ei.columbia.edu/files/2016/04/Fig.-1.-Fossil-fuel-CO2-emissions-left-scale-and-airborne-fraction-620×338.png
Hansen, J., Kharecha, P., & Sato, M. (2013). Climate forcing growth rates: doubling down on our Faustian bargain. Environmental Research Letters, 8(1), 011006.
http://iopscience.iop.org/article/10.1088/1748-9326/8/1/011006
Wetlands are not a carbon sink.
A good way of looking at this is rice paddies. The IPCC’s carbon balance lists
rice paddies as a man caused CH4 source.
Before the paddies are flooded, the upwelling natural gas and the locally
generated CH4 are in balance with the microbes which oxidize it, and CO2
could be measured. When the farmer floods the paddies, the water forces
the hydrocarbons to rise faster than the microbes can consume them, so the
carbon is measured as a CH4.
There is no change, ultimately, in the carbon in the atmosphere.
In the wetlands, when wet, the gas rises as a hydrocarbon. When the water
is drained, the aerobic microbes bloom to the amount of food available,
oxidize the hydrocarbons, and CO2 rises.
CO2 readings at the ground level are a highly local event. This is the reason
for widely varying stomata readings from different locations the same year. The
total ambient atmospheric carbon, CO2 plus hydrocarbons, before human
contribution excluding volcanoes, oceans, etc, depend upon the amount
of the earth not frozen.
The richness of the soil is a visual guide. The richer the soil, the more
hydrocarbons upwelling through it, the more the local culture can eat,
oxidize, and the CO2 reading at the surface will be higher.
A simple way to test this requires a CO2 meter and a 12″ stainless
steel salad bowl and a 10 lb weight.
I recently did this test on my property. On a day with less than 3 mph
wind, I measured the CO2 reading at 6′. 404 ppm. I placed the meter on
the ground, covered it with the inverted ss bowl, placed the 10 lb weight
on it, and left it there for 12 hours. The reading at the end of the 12 hr
period was 1394 ppm.
The carbon from this area will be about the same as long as it is not
covered in ice, short of a tectonic shift.
The plants were never in danger of dying for lack of food.
Peat bogs are famous for trapping carbon for 10’s of thousands of years.
That’s fascinating. You stop photosynthesis, and then you notice that no CO2 has been taken up.
Jerry it also depends on when you take the readings. On a field of corn the bacteria and other organic sources build up the [CO2] later in the day and through the night but when morning there is a feeding frenzy as the plants gobble it up reducing concentration by half.
This is why on the course I look after the importance of morning sun for good growth can’t be overstated….ed
http://joannenova.com.au/2013/09/plants-suck-half-the-co2-out-of-the-air-around-them-before-lunchtime-each-day/
Polski,
The reason for the stainless steel bowl is to isolate the location from ambient
influences. Take the reading for 24hrs. Just do other soil tests the same way
so that the comparison is valid.
Measure the ground temperature with a probe and check the same spot when
it is warmer and colder and even when the ground is frozen. Test when the
ground is very wet and when the ground is very dry.
The Greening Earth (Source: NASA):
Interesting card. It also shows that the greatest profit of the greening are average widths, not the arctic regions. Apart from eastern Siberia, there are also marked declines in leaf areas. Profiteers are southern and eastern Europe (quite contrary to the horror of the IPCC) and India. In this case, the sharp drop in the leaf surface in the inner Himalayas is noticeable, whereas the surface of the leaf clearly increases on the slope of the Hialaya and the lower continent.
This change of variability as a function of change of scale of measurement has a name in geostatistics – the support of the measurement. Variance is always preserved under smoothing, so if you have measures of variance at different scales and know the resolution of the sample (ie its effective volume on which the measure was made) then you can estimate the variance at other scales.
This observation was part of the empirical MSc thesis submitted by none other than Danie Krige (of Kriging fame), back in 1951.
There is an excellent discussion of the topic and its solution/calculation in the book “An Introduction to Applied Geostatistics” by Isaaks and Srivastava (Oxford, 1989). See Chapter 19 Change of Support.
This explains very clearly why you cannot splice together data at different measurement resolution. Like the Hockey Stick and Marcott’s uptick. Its bollocks. It also explains how the statistics, and particularly the variability and presence of extremes I changed as the measurement is made at lower resolution. the same thing happens when infilling or extrapolating grids too.