IPCC 5 AR Now Claims Anthropogenic Warming Is Offset By Anthropogenic Cooling! You’ve Got To Be Kidding!

Ever wonder why IPCC scientists are losing credibility?

Rudolf Kipp in a reader comment here points out an interesting claim being made by the IPCC 5 AR Summary for Policymakers (SPM) on page 10. It states:

The greenhouse gas contribution to the warming from 1951–2010 is in the range between 0.6 and 1.4°C. This is very likely greater than the total observed warming of approximately 0.6°C over the same period. {10.3.1}

What they are saying here is that the warming due to CO2 may have been as much as 1.4°C, but some external factor may have cooled the globe and offset much of that warming. According to the IPCC it is actually 0 to 0.8°C cooler than it should be. Chapter 10 (Page 15) mentions aerosols as the likely cooling factor:

Over the 1951–2010 period, greenhouse-gas-attributable warming at 0.6–1.4 K is significantly larger than the observed warming of approximately 0.6 K, and is compensated by an aerosol-induced cooling of between 0 and –0.8 K (Figure 10.4b) (Jones et al., 2012).”

That means that the man-made global warming is actually more than what the temperature rise shows. This is because man-made aerosol cooling offsets a part of the warming. Kipp surmises:

If it doesn’t get warmer over the next years, then it likely will be blamed on the increased share of anthropogenic cooling.”

Obviously the IPCC is giving itself a back door for an escape should temperatures continue to stay flat or fall. No matter what happens, the IPCC will blame man-made climate change.

Kipp writes:

Is it any wonder that the credibility of climate scientists within the public has fallen to levels we usually associate with used car dealers or politicians?

With this latest wishy-washy claim, the IPCC  is thus admitting their models have huge uncertainty. This is hardly the kind of science that policy should be based upon.


11 responses to “IPCC 5 AR Now Claims Anthropogenic Warming Is Offset By Anthropogenic Cooling! You’ve Got To Be Kidding!”

  1. IPCC 5 AR Now Claims Anthropogenic Warming Is Offset By Anthropogenic Cooling! You’ve Got To Be Kidding! | Cranky Old Crow

    […] IPCC 5 AR Now Claims Anthropogenic Warming Is Offset By Anthropogenic Cooling! You’ve Got To Be Ki…. […]

  2. Edward.

    Man made this, that and the other – the IPCCAR5 is a dead duck by the time it is released everybody will know – what a complete waste of time it all was…btw don’t bother with no 6.


    Earth and balance = equilibrium.

    It’s the natural way; it gets a bit warmer and the air picks up more moisture and then it rises and causes cloud formation and as it rises [see the second law thermodynamics] it cools the air it condenses and falls usually as rain…… a bit more warm and wet and up and down and so it goes – it gets a bit cooler.

    Here endeth the first lesson.

    P.S. Can you send me a noble prize?

  3. ArndB

    From Draft_AR5- p.49; “FAQ 5.1: Is the Sun a Major Driver of Climate Changes?
    ___The Sun is the ultimate source of the energy that powers the climate system.
    ___Over the past 120 years, solar variability is one of three recognised natural sources of climate variability that, together with anthropogenic factors, combine to explain much of the observed changes in global surface temperatures (Chapter 10).
    ___However, that variability has made only a minor contribution to the observed increase in global surface temperatures over the past 120 years.”

    The last statement is gross guessing! The sun energy stored in the ocean, the merely 4°C average temperature of the oceans, and 30 times total exchange of the atmospheric water content, to which the ocean supplies 85% is the key to the status, respectively change, of global air temperatures. Any man-made changes in the marine environment are very likely to contribute significantly in the “climate change” scenario. E.g. the impact of shipping etc is discussed HERE: http://www.ocean-climate-law.com/Draft/home.html

  4. Mindert Eiting

    They are claiming a type II error. Of course they do because a null hypothesis was not rejected. Just by chance (aerosols) the temperatures did not went up as much as hoped. And what is the probability of that error? I want to do the dangerous proposal to compute that probability in stead of losing time with whining and gnasting of teeth.

  5. Rudolf Kipp


    can anyone figure out how the claim of increased cooling due to a bigger effect of aerosols fits in with a decrease in aerosol forcing claimed in Chapter 8 (found on WUWT)?

    Table 8.7 shows that the best estimate for total aerosol RF (RFari+aci) has fallen from −1.2 W/m² to −0.7 W/m² since AR4, largely due to a reduction in RFaci, the uncertainty band for which has also been hugely reduced.

    From This graph one can get the change in aerosol forcing from 1951 to 2010, which is roughly -0,5 W/m². This should result in a cooling of maybe -0,15 °C.

    This is in contradiction to the claim in the SPM and in Chapter 10, that net cooling would be significantly more (0 – -0,8 °C). The reference for the claim of an up to -0,8 °C aerosol cooling since 1951 is given as Jones et al., 2012, which should be
    Jones, G. S., P. A. Stott, and N. Christidis, 2012: Attribution of observed historical near surface temperature variations to anthropogenic and natural causes using CMIP5 simulations.
    Unfortunately I cannot find this paper anywhere, maybe it is still in press.

  6. Ed Caryl

    Oh what a tangled web we weave,
    When first we practise to deceive!
    Sir Walter Scott, Marmion, Canto vi. Stanza 17.
    Scottish author & novelist (1771 – 1832)

  7. mwhite



    “Earth’s stratosphere is as clear as it’s been in more than 50 years. ”

    “”Since 1996, lunar eclipses have been bright, which means the stratosphere is relatively clear of volcanic aerosols. This is the longest period with a clear stratosphere since before 1960.” Consider the following comparison of a lunar eclipse observed in 1992 after the Philippine volcano Pinatubo spewed millions of tons of gas and ash into the atmosphere vs. an “all-clear” eclipse in 2003:”

  8. Bruce of Newcastle

    When they say “aerosols as the likely cooling factor” they actually mean sulfur emissions. They don’t mean black carbon, which is a warming agent.

    And the main anthropogenic source of atmospheric sulfur aerosols is burning of dirty coal in China.

    The problem for the IPCC is it suggests a method for “fixing” global warming which not only doesn’t cost anything but actually saves money.

    All you need to do is turn off all the flue gas desulfurisation (FGD) units the greens forced onto coal fired power station operators in Western countries at great cost.

    It would have the effect of making dirty sulfurous coal for power generation the best and cheapest anti-greenhouse option there is.

    Pity there isn’t actually much AGW for the IPCC to save us from, as I do love the law of unanticipated consequences.

  9. Robert of Ottawa

    Epicycles anyone?

    1. DirkH

      Warmism is a degenerative research program:
      Lakatos claimed that not all changes of the auxiliary hypotheses of a research programme (which he calls ‘problem shifts’) are equally productive or acceptable. He took the view that these ‘problem shifts’ should be evaluated not just by their ability to defend the ‘hard core’ by explaining apparent anomalies, but also by their ability to produce new facts, in the form of predictions or additional explanations.[6] Adjustments that accomplish nothing more than the maintenance of the ‘hard core’ mark the research programme as degenerative.

  10. Doug Cotton

    If anyone wishes to ask questions about my paper, ‘Planetary Surface Temperatures A Discussion of Alternative Mechanisms” or if you believe you have an alternative explanation for the Venus surface temperature, please post your question or response below this post as I wish to keep all discussion on the one thread. There is also discussion there regarding today’s article on PSI which I did not write myself, by the way.

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this. More information at our Data Privacy Policy