Sunday, June 26, 2011

CO2 levels have risen at the same rate for past 18,000 years

While climate alarmists claim CO2 levels have risen at an unprecedented rate since the industrial revolution, extrapolation from ice core data shows the rate of rise has been steady since the peak of the last ice age about 18,000 years ago. This shows that man-made CO2 (~3% of total emissions) has had little effect on atmospheric levels of CO2, which instead are driven by outgassing from the oceans during interglacial periods; interglacial periods are driven by solar insolation, not CO2.
Atmospheric CO2 from 3 ice-core studies shown on vertical axis, thousands of years ago shown on horizontal axis. Linear extrapolation from the peak of the last ice age ~18,000 years ago shows that the rate of rise in CO2 has not changed over the past 18,000 years. Notations in red added. Graph source.

8 comments:

  1. CO2 also rose 100ppm during the Eemian. And then the Eemian was over.

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  2. Between 10000 years ago and 250 years ago it stayed practically constant. @first commentator: look up the Milankovitch cycles.

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  3. Hold up a second.

    Figure 3 in Bump et. al. does not include the read analysis you've added here. On what basis have you chosen to extend the analysis with a linear regression? What other analysis have you performed to show that this analysis is valid in any way - statistical tests, comparisons with epochs of known temperature/CO2, comparison with other CO2 reconstructions?

    The point of this paper isn't to reconstruct CO2 variations of the past 1000 years. It's sole purpose is to highlight what the authors think is a better metric for a very short historical epoch - the post-glacial maximum proceeding the Last Glacial Maximum, which is a history of rapid, naturally-forced climate change. Of course, the word "rapid" is relative, because while this study shows a CO2 increase of about 100 ppm over 6,000 years, we've observed - directly - that CO2 has increased about that much over roughly a **one hundred year** period.

    We have many independent analyses of atmospheric CO2 which refute the 'analysis' you proffer here. The same page references many studies (isotopic d13C/d12C ratios) that refute your assertion that man-made CO2 is only 3% of total emissions.

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  4. Oh this is rich. Even a glance at the MEASUREMENTS (not extrapolation) for the last 50 years shows this is complete bollocks.

    https://secure.wikimedia.org/wikipedia/en/wiki/File:Mauna_Loa_Carbon_Dioxide-en.svg

    The last 400 years? http://snowhare.com/climate/charts/atmospheric_co2_1600_to_2009.png

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  5. Counters: The CDIAC ice core analysis you link to in fact supports my post. See the rapid essentially linear rise in CO2 over the past ~18000 years here

    http://cdiac.ornl.gov/trends/co2/graphics/vostok.co2.gif

    if I had extended this graph instead the result would have essentially been the same, ending up with the present day CO2 level at 0 y BP. [ice cores cannot provide data up to the present and are artificially linked to the Mauna Loa data using controversial methods]

    Unknown:

    The rise in CO2 over the last 30 years has been essentially linear:

    http://hockeyschtick.blogspot.com/2010/01/time-to-double-co2-levels-467-years.html

    40-50 years ago was a period of global cooling during which rate of rise slowed a bit. Prior to that we have Georg Beck's data

    http://www.biomind.de/realCO2/

    and ice core data. The last 400 years was mostly during the Little Ice Age up until ~1850 when CO2 levels would be expected to take a break from the mostly steady rise over the past ~18000 years.

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  6. > The CDIAC ice core analysis you link to in fact supports my post. See the rapid essentially linear rise in CO2 over the past ~18000 years here

    You're arguing apples to oranges and selectively misrepresenting the data. Look at the temporal resolution of the data in the Vostok chart. The analysis in Bump et al is literally a millimeter-wide smidgen of the Vostok ice core, and it's a necessary analysis because the ice core doesn't provide the necessary resolution to really see what is going on on short timescales.

    Furthermore, it's a cherry pick of the evidence available at the CDIAC site. The curious reader can see shorter plots from Law Dome and see that your analysis here and inference from Vostok is unsupported by appropriate data.

    > if I had extended this graph instead the result would have essentially been the same, ending up with the present day CO2 level at 0 y BP.

    And again - on what basis can you extend the graph? What other evidence do you offer that atmospheric CO2 concentrations follow a multi-thousand year trend of roughly 10 ppm/1000 years, especially in light of the fact that higher-resolution data from Law Dome and elsewhere directly refute this relationship and show no statistically significant increase until after ~1870?

    > [ice cores cannot provide data up to the present and are artificially linked to the Mauna Loa data using controversial methods]

    Yes, but *do you know why* they can't provide data up to the present? It's because of the processes through which air gets trapped in bubbles in the ice sheet and is mixed with air from the surrounding decades on either side. Nevertheless, there *are* sophisticated techniques employed by researchers at Scripps Institution of Oceanography and many other world-class research facilities which are designed to help analyze these data sources.

    I will note that you wave your hand and call these methods "controversial" without any analysis and technical criticism of them. The reader can infer what they wish from this omission.

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  7. Counters: Using the Vostok data you linked to:

    From 17695 YBP to 11013 YBP CO2 increased from 182.2 to 263.7 ppm, which roughly appears to agree with the graph in this post, a rate of .0122 ppm/year. The past 11013 years * .0122 ppm/yr = 134 ppm. 263.7 + 134 = 397.7, slightly more than the present CO2 level. This is what the extension of the graph in this post illustrates. Have there been bumps along the way due to the little ice age, etc.? Yes, but the point is a linear extrapolation shows the overall rate over the past 18K years is essentially unchanged.

    Yes, I know why the ice core linkage is controversial and many other controversies regarding ice core data and have covered it a number of times on this site, with a few posts here:

    http://hockeyschtick.blogspot.com/search?q=jaworowski

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  8. The Ice Age is not a very old concept. It was not thought of in the 1700s, just like the theory of evolution was not widely known then either. This theory only gained ground in the 1840s when two researchers, Charpentier and Agassiz, tried to explain the forms of the Alps by the theory and later expanded it to apply to the whole of Northern Europe. It is surprising that this theory came to light almost at the same time as Darwin's idea of the origin of species. Both of these theories gained simultaneous attention in the society of that time.

    It has been thought that there have been several Ice Ages on the Earth. It has even been said that tropical and hot areas like the Sahara, Africa, Saudi Arabia, Yemen, Australia, India, Madagascar, and South America (as presented in the books Jääkausi (Ice Age) / Björn Kurten and Muuttuva maa / Pentti Eskola, for example) were covered with a large continental glacier tens of millions of years ago. The latest Ice Age is assumed to have started "just" about 500,000 years ago and ended 10,000 years ago. The ice sheets are believed to have covered at their widest 55 million square meters, and the thickness of the ice was at most over 3 kilometers (about 1.8 miles).
    What should we think about the Ice Age? Have we any reason to believe in it? Maybe the signs that have been interpreted as signs of an Ice Age were caused by something else? We will now study the mystery of the Ice Age.

    http://www.jariiivanainen.net/Has_there_ever_been_the_ice_age.html

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