Tuesday, March 19, 2013

New paper finds CO2 spiked to levels higher than the present during termination of last ice age

A new paper published in Quaternary Science Reviews reconstructs CO2 levels during the termination of the last ice age and finds CO2 spiked to levels near or even exceeding those of the present, obviously without any human influence. According to the authors, "The record clearly demonstrates that [CO2 levels were] significantly higher than usually reported for the Last [Glacial] Termination," with levels of up to ~425 ppm about 12,750 years ago, which exceeds the present CO2 concentration of 395 ppm. 


Left graph shows CO2 concentrations varied dynamically between ~220-425 ppm from 14,000-11,500 years ago. Ice core comparison is shown at right.
Related: From the paper by EG Beck showing chemical measurements of CO2 levels of up to ~480 ppm during the 1800's 
Related: New blockbuster paper finds man-made CO2 is not the driver of global warming


Stomatal proxy record of CO2 concentrations from the last termination suggests an important role for CO2 at climate change transitions

  • a Department of Geological Sciences, Bolin Centre for Climate Research, Stockholm University, SE 109 61 Stockholm, Sweden
  • b School of Geography, Archaeology and Palaeoecology, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom


Abstract

A new stomatal proxy-based record of CO2 concentrations ([CO2]), based on Betula nana (dwarf birch) leaves from the Hässeldala Port sedimentary sequence in south-eastern Sweden, is presented. The record is of high chronological resolution and spans most of Greenland Interstadial 1 (GI-1a to 1c, Allerød pollen zone), Greenland Stadial 1 (GS-1, Younger Dryas pollen zone) and the very beginning of the Holocene (Preboreal pollen zone). The record clearly demonstrates that i) [CO2] were significantly higher than usually reported for the Last Termination and ii) the overall pattern of CO2 evolution through the studied time period is fairly dynamic, with significant abrupt fluctuations in [CO2] when the climate moved from interstadial to stadial state and vice versa. A new loss-on-ignition chemical record (used here as a proxy for temperature) lends independent support to the Hässeldala Port [CO2] record. The large-amplitude fluctuations around the climate change transitions may indicate unstable climates and that “tipping-point” situations were involved in Last Termination climate evolution. The scenario presented here is in contrast to [CO2] records reconstructed from air bubbles trapped in ice, which indicate lower concentrations and a gradual, linear increase of [CO2] through time. The prevalent explanation for the main climate forcer during the Last Termination being ocean circulation patterns needs to re-examined, and a larger role for atmospheric [CO2] considered.

Highlights

► A stomatal proxy-based CO2 record from the Last Termination is presented. ► The stomata based CO2record is much more dynamic than ice core-based CO2 records. ► CO2 first increases abruptly before decreasing at cooling transitions and vice versa.

5 comments:

  1. http://www.theclimatescam.se/2013/06/07/betula-nana/

    ReplyDelete
  2. http://www.eike-klima-energie.eu/climategate-anzeige/klimawandel-in-deutschland-bedeutet-abkuehlung-trotz-deutlicher-zunahme-von-co2-teil-2/

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  3. http://www.amlibpub.blogspot.com/2013/06/exposing-global-warming-fraud.html

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  4. Excerpts from Dr. Murry Salby's 2012 textbook, Physics of the Atmosphere and Climate:
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    “The resemblance between observed changes of CO2 and those anticipated from increased surface temperature also points to a major inconsistency between proxy records of previous climate. Proxy CO2 from the ice core record (Fig 1.13) indicates a sharp increase after the nineteenth century. At earlier times, proxy CO2 becomes amorphous: Nearly homogeneous on time scales shorter than millennial, the ice core record implies virtually no change of atmospheric CO2. According to the above sensitivity, it therefore implies a global-mean climate that is “static,” largely devoid of changes in GMT and CO2. Proxy temperature (Fig. 1.45), on the other hand, exhibits centennial changes of GMT during the last millennium, as large as 0.5–1.0◦ K. In counterpart reconstructions, those changes are even greater (Section 1.6.2). It is noteworthy that, unlike proxy CO2 from the ice core record, proxy temperature in Fig. 1.45 rests on a variety of independent properties. In light of the observed sensitivity, those centennial changes of GMT must be attended by significant changes of CO2 during the last millennium. They reflect a global-mean climate that is “dynamic,” wherein GMT and CO2 change on a wide range of time scales. The two proxies of previous climate are incompatible. They cannot both be correct.” pg. 254
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    “Revealed by natural perturbations to the Earth-atmosphere system, the sensitivity accounts for much of the observed variation of CO2 emission on interannual time scales (Fig. 1.43). It establishes that GMT cannot increase without simultaneously increasing CO2 emission – from natural sources.” pg. 253
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    “Warming of SST (by any mechanism) will increase the outgassing of CO2 while reducing its absorption. Owing to the magnitude of transfers with the ocean, even a minor increase of SST can lead to increased emission of CO2 that rivals other sources.” pg. 546
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    “Surface temperature depends on the atmosphere’s optical depth. The latter, in turn, depends on atmospheric composition through radiatively active species. Water vapor is produced at ocean surfaces through evaporation. Carbon dioxide is produced by decomposition of of organic matter. These and other processes that control radiatively active species are temperature dependent.” pg 249,250
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    “The vast majority of that [greenhouse] warming is contributed by water vapor. Together with cloud, it accounts for 98% of the greenhouse effect.” pg. 249
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    “Together, emission from ocean and land sources (∼150 GtC/yr) is two orders of magnitude greater than CO2 emission from combustion of fossil fuel. These natural sources are offset by natural sinks, of comparable strength. However, because they are so much stronger, even a minor imbalance between natural sources and sinks can overshadow the anthropogenic component of CO2 emission.” pg. 546

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    Replies
    1. Those are all great quotes, thanks.

      Is there a free online version of his textbook somewhere?

      Delete

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