IPCC Reports: Then and Now

Posted: September 17, 2012 by tallbloke in climate, government, Incompetence

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Third Assessment Report: 2003

 “Most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations”.

Fourth Assessment Report: 2007

“Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.”

Fifth Assessment Report: 2012 (draft)

“Climate change may be due to natural internal processes or external forcings, or to persistent anthropogenic changes in the composition of the atmosphere or in land use.”

It seems that the 95% confidence interval associated with the IPCC definition of “very likely” is now worth no more than a toss of the coin. How much have we been paying these people to produce “Well crafted figures and punchy take home messages“?

Still, look on the bright side, the overpaid and underclued IPCC numpties are starting to wander in the right direction. 🙂

Roger Pielke Sr also notes that the definition of climate change itself has changed:

It is interesting to note that the Inter-Governmental Panel on Climate Change (IPCC) (IPCC, 2012) has recently redefined climate change as

“A change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings, or to persistent anthropogenic changes in the composition of the atmosphere or in land use”.

This is different from the previous definition. IPCC states

“This definition differs from that in the United Nations Framework Convention on Climate Change (UNFCCC), where climate change is defined as: “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability.”

This is a sneaky move. In effect they are making a post hoc rationalisation to make their previous position more tenable, or a least less untenable…

Of course it remains to be seen whether the IPCC will put figures on the relative natural and anthropogenic contributions to climate change in the final version of the summary for policy makers.

Perhaps it’ll look a bit like one of the MET Office’s statements:

“We’re 40% certain at least 30% of the weather forecasts will be at least 30% correct.”

Comments
  1. omnologos says:

    Can’t wait for the day the IPCC loses the second C

  2. Skeptikal says:

    “We’re 40% certain at least 30% of the weather forecasts will be at least 30% correct.”

    Now that’s what I call confidence!

  3. vukcevic says:

    Communicating science to the masses

  4. Ilma says:

    The IPCC have realised that the human element in the changing climate (if indeed if there is one) is of no consequence. If they truthfully admitted that though, they would have to immediately close up shop, go home, and look for real jobs.

    Governments need to stand up, challenge the IPCC to demonstrate that their presence is justifiable, and if (when) not, demand its complete and final closure.

  5. Bob Tisdale says:

    tallbloke says: “Roger Pielke Sr also notes that the definition of climate change itself has changed…”

    I believe that was the guest author you quoted.

    Also the quote “Climate change may be due to natural internal processes or external forcings, or to persistent anthropogenic changes in the composition of the atmosphere or in land use.” also appears in AR4. It’s nothing new.
    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/annex1sglossary-a-d.html

  6. tallbloke says:

    Hi Bob, the quoted statement from IPCC saying:

    “This definition differs from that in the United Nations Framework Convention on Climate Change (UNFCCC), where climate change is defined as: “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability.”

    Seems pretty unequivocal. Maybe Pielke Sr’s guest author was quoting the above from AR4 too.
    Anyhow, don’t worry, this post is a bit of tongue in cheek fun. We like to let off steam every now and then. Let’s hope it doesn’t start a runaway water vapour feedback. 😉

  7. berniel says:

    Be careful Tallbloke, in your haste you might be missing something here that is much more interesting.

    S. Raghavan (at R. Pielke) quotes the IPCC quoting the FCCC definition of climate change. I haven’t looked in the recent Reports, but the wording ‘this definition differs from…’ should have raised your suspicions as to whether this was an IPCC definition. I dont know Raghavan’s precise source but this wording is very similary to the wording in the footnote on the first page of the WG1 Summary for Policymakers in SAR, where we find ‘This differs from the usage in the FCCC…’ Here it follows the definition used by IPCC WG 1, which uses a definition closer to the one quoted from the draft Fifth Assessment. This suggests that AR5 remains consistent with SAR in defining ‘climate change’ as including both natural and anthropogenic forcing.

    What is more interesting is how this distinction between the IPCC definition and the FCCC definition — the scientific definition and the political definition — was inserted on the front page of the SPM. This was a win by Australia in the WG1 Madrid Plenary.

    The distinction is also made on the first page of the Technical Summary (p13) and in the Glossary of the original SPM (now the glossary of the Technical Summary – see SAR p48). In the Glossary there is also the statement ‘It is generally not possible clearly to make attribution between [natural and anthropogenic] causes.’ ‘Not possible’ means ‘impossible’ yes? Is that 95% or 100% certainty? Anyway, this is suggesting that we should be sceptical of any claim to have positively attributed climate change to the human cause. And yet the SAR ended with just such a (however weak) claim. The USA comments tabled at Madrid ask for the removal of this sentence from the Glossary — it does not really belong in a definition! But it never happened. It seems they ran out of time pushing through the ‘human influence’ attribution claim, and history shows that it didnt matter that it stayed their because no one seemed to notice or care about these and other striking inconsistencies in the Report.