Sunday, September 21, 2014

New paper shows nature absorbs ~83% of man-made CO2 emissions, much more than previously thought

A paper published today in Earth System Science Data Discussions analyzes the 2014 carbon budget and predicts man-made CO2 emissions from fossil-fuels and cement production have increased by 65% since 1990. However, atmospheric levels of CO2 have only increased by 11% since 1990, indicating that ~83% of man-made emissions have been absorbed by natural sinks, far greater than the IPCC belief that natural sinks absorb 50% of man-made emissions. 

Thus, natural sinks [such as the up to 30% greening of the planet over the past few decades] are expanding faster than the IPCC anticipated, CO2 lifetime in the atmosphere is much less than the IPCC believes, or the source of the increase is primarily natural due to ocean outgassing, or some combination of the three. 

Thus, the IPCC assumptions about greenhouse "pathways" and "warming in the pipeline" are exaggerated, erroneous, and overheated. 

Further, the 65% increase in CO2 emissions was only associated with 0.2C warming since 1990. If we make the false assumption that 100% of the warming since 1990 was due to man-made CO2 emissions, we can calculate the climate sensitivity to man-made emissions as

~0.2C = x*ln(1.65), where x = 0.399 [13 times less than the 5.35 fudge factor (x) the IPCC uses]

Thus a doubling of man-made emissions [as opposed to net atmospheric levels] of CO2, assuming all warming is due to man-made CO2 emissions, would produce a temperature rise of only 0.28C, in line with several other observational estimates of low climate sensitivity to CO2 levels:

0.399*ln(2) = .28C


Earth Syst. Sci. Data Discuss., 7, 521-610, 2014
www.earth-syst-sci-data-discuss.net/7/521/2014/
doi:10.5194/essdd-7-521-2014



C. Le Quéré1, R. Moriarty1, R. M. Andrew2, G. P. Peters2, P. Ciais3, P. Friedlingstein4, S. D. Jones1, S. Sitch5, P. Tans6, A. Arneth7, T. A. Boden8, L. Bopp3, Y. Bozec9,10, J. G. Canadell11, F. Chevallier3, C. E. Cosca12, I. Harris13, M. Hoppema14, R. A. Houghton15, J. I. House16, A. Jain17, T. Johannessen18,19, E. Kato20, R. F. Keeling21, V. Kitidis22, K. Klein Goldewijk23, C. Koven24, C. S. Landa18,19, P. Landschützer25, A. Lenton26, I. D. Lima27, G. Marland28, J. T. Mathis12, N. Metzl29, Y. Nojiri20, A. Olsen18,19, T. Ono30, W. Peters31, B. Pfeil18,19, B. Poulter32, M. R. Raupach33, P. Regnier34, C. Rödenbeck35, S. Saito36, J. E. Salisbury37, U. Schuster5, J. Schwinger18,19, R. Séférian38, J. Segschneider39, T. Steinhoff40, B. D. Stocker41, A. J. Sutton12,42, T. Takahashi43, B. Tilbrook44, G. R. van der Werf45, N. Viovy3, Y.-P. Wang46, R. Wanninkhof47, A. Wiltshire48, and N. Zeng49

Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe datasets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates, consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics and cement production data, respectively, while emissions from Land-Use Change (ELUC), mainly deforestation, are based on combined evidence from land-cover change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean COmeasurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent Dynamic Global Vegetation Models forced by observed climate, CO2 and land cover change (some including nitrogen-carbon interactions). We compare the variability and mean land and ocean fluxes to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2004–2013), EFF was 8.9 ± 0.4 GtC yr−1ELUC 0.9 ± 0.5 GtC yr−1GATM 4.3 ± 0.1 GtC yr−1SOCEAN 2.6 ± 0.5 GtC yr−1, and SLAND 2.9 ± 0.8 GtC yr−1. For year 2013 alone, EFF grew to 9.9 ± 0.5 GtC yr−1, 2.3% above 2012, contining the growth trend in these emissions. ELUC was 0.9 ± 0.5 GtC yr−1GATM was 5.4 ± 0.2 GtC yr−1SOCEAN was 2.9 ± 0.5 GtC yr−1 and SLAND was 2.5 ± 0.9 GtC yr−1GATM was high in 2013 reflecting a steady increase in EFF and smaller and opposite changes between SOCEAN and SLAND compared to the past decade (2004–2013). The global atmospheric CO2 concentration reached 395.31 ± 0.10 ppm averaged over 2013. We estimate that EFF will increase by 2.5% (1.3–3.5%) to 10.1 ± 0.6 GtC in 2014 (37.0 ± 2.2 GtCO2 yr−1), 65% above emissions in 1990, based on projections of World Gross Domestic Product and recent changes in the carbon intensity of the economy. From this projection of EFF and assumed constant ELUC for 2014, cumulative emissions of CO2 will reach about 545 ± 55 GtC (2000 ± 200 GtCO2) for 1870–2014, about 75% from EFFand 25% from ELUC. This paper documents changes in the methods and datasets used in this new carbon budget compared with previous publications of this living dataset (Le Quéré et al., 2013, 2014). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_2014). 

17 comments:

  1. Cannot thank you enough for your hard work and eagle eye in digging up these key paper.

    So just a plain, Thank you.

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  2. I concur with Frederick. Excellent work and many thanks for it.

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    Replies
    1. Thanks much to you both & thanks for your interest in the blog

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  3. Epicycles. They're trying to explain the divergence between emissions and atmospheric concentration by adjusting the sink rate, rather than simply acknowledging that atmospheric concentration does not depend significantly on emissions at all, but on temperatures.

    - Bart

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  4. Yeah, and my contribution to my IRA doubled this year but my portfolio only went up 2 %. So who stole the extra 98%? Huh? Who done it?

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    Replies
    1. It's the expanding natural sinks that done it, I tell ya, they done it.

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  5. Suppose that in year 1 there was a very minute amount of compound X being released into the atmosphere. Then suppose that in year 2 there was 50% more of compound X being released, still a minute amount. Can we assume that therefore there should be 50% more of compound X in the atmosphere? Suppose that in year 1 there was already a huge amount of compound X in the atmosphere. If we add a minute amount in year 2 that is not going to result in 50% more in the atmosphere, will it?

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  6. Using the atmospheric CO2 figures here:

    ftp://aftp.cmdl.noaa.gov/products/trends/co2/co2_annmean_mlo.txt

    We get the following CO2 ppm values since 1970:
    --------------------------------
    1970: 325.7 ppm
    1990: 354.4 ppm
    2013: 396.5 ppm
    2014: estimated to be 399 ppm
    --------------------------------
    The rate of increase in CO2 ppm per year for the two periods are:
    --------------------------------
    1970-1990 = +1.37 ppm/yr
    1990-2014 = +1.77 ppm/yr
    --------------------------------
    So comparing the rate of change in atmospheric CO2 for 1970 – 1990 to 1990 – 2014, we see that the rate of increase per year in atmospheric CO2 ppm rose by 29% (1.37 ppm to 1.77 ppm) from the 1970-’90 period to the 1990-’14 period .
    --------------------------------
    According to the IPCC (TAR, AR4), the gigatons of carbon (GtC) emitted from anthropogenic sources were:
    ---------------------------------
    1970: 4.3 GtC
    1990: 6.1 GtC
    1999: 6.5 GtC
    2005: 7.8 GtC
    2014: 10.1 GtC (per the 2014 Global Carbon Budget estimate)
    ---------------------------------
    So we see here that from 1970 to 1990, there was an increase of .086 GtC/yr in human emissions (4.3 GtC/yr in 1970 to 6.1 GtC/yr in 1990), whereas from 1990 (6.1 GtC) to the projected 2014 GtC number of 10.1 per the GCB 2014, there has been an increase of .16 Gtc/yr. That’s an 86% increase in the rate of GtC emissions emitted per year from anthropogenic sources during 1990-‘14 relative to 1970-’90, versus an increase of only 29% in atmospheric CO2 ppm per year over the same comparative period. That means that there has been nearly 3 times as much of an increase in anthropogenic CO2 emissions per year as there has the rate of increase in atmospheric CO2 ppm per year in the last 4 to 5 decades .
    ---------------------------------
    No wonder Hansen’s 2013 paper showed an incongruous rise in anthropogenic CO2 emissions relative to the rate of change in atmospheric CO2:

    http://ej.iop.org/images/1748-9326/8/1/011006/erl459410f3_online.jpg

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    Replies
    1. Yes exactly - I showed Hansen's airborne fraction of man-made CO2 has decreased ~25% over past ~52 years and his struggles to explain this "paradox" in this post

      http://hockeyschtick.blogspot.com/2013/03/hansens-mea-culpa-says-man-made-global.html

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    2. Why isn't this answered by the IRA example above, where a 100% increase in contribution resulted in only a 2% increase in resulting fund?

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  7. Using the IPCC figure for emissions in 1970, there has been an increase of man-made emissions 1970-2014 of 234%, and temp change per HADCRU of 0.65C

    Plugging these into the formula above gives

    .65C = x*ln(2.34), where x = 1.308

    1.308*ln(2) = 0.91C climate sensitivity to a doubling of man-made CO2 emissions during the 44 year period of 1970-2014.

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    Replies
    1. How long does it take for the climate to respond? Can we say that in 2014 the climate has responded to all the emissions up through 2014?

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    2. Most of the response is instantaneous "Transient climate response" and allegedly 20% later "equilibrium response" per Otto et al, but I believe that is exaggerated as well due to false assumptions about CO2 lifetime and feedbacks.

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  8. I would appreciate some help understanding this point, if anybody is able. Apparently, the IPCC says that studies showing that radiocarbon leaves the atmosphere very quickly cannot be used to show the true residence time of CO2 in the atmosphere because individual molecules of CO2 that enter one of the sinks, such as the ocean, are replaced by molecules of CO2 entering the atmosphere from a sink, resulting in only a net of 2 Gton C per year entering the ocean. So while the radiocarbon has left the atmosphere it has been replaced by CO2 from a sink, resulting in almost the same amount remaining in the atmosphere. But if there is an increased amount going from the atmosphere to the ocean this theory says that an almost equal amount will then leave the ocean and enter the atmosphere. But how is this supposed to work? Like billiards, where one ball is hit into a cluster and one ball exits the other side? Is there an explanation of this somewhere?

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  9. Watch Salby talk over here------------>

    & type "gosta" in search box for more

    ReplyDelete