Climate sensitivity and Climategate 2.0

Climate sensitivity distribution. 3 C is the upper limit (click to enlarge)

Some break this is turning out to be! Climate stories are breaking every day, and they deserve some coverage here. Two articles in The Australian today are of particular interest.

Firstly, the publication of a paper in Science that questions the high-end climate sensitivity probabilities put forward by the IPCC. Remember, climate sensitivity is the KEY question. If the climate isn’t sensitive to CO2, then “man-made global warming” is a non-problem. It’s the fact that the climate models project that there is a real possibility of significant climate sensitivity, leading to substantial and dangerous warming, which is enough, the IPCC would argue, to justify drastic emissions cuts based on the precautionary principle. The problem is that it may not be true:

DRAMATIC forecasts of global warming resulting from a doubling of atmospheric carbon dioxide have been exaggerated, according to a peer-reviewed study by a team of international researchers.

In the study, published today in the leading journal Science, the researchers found that while rising levels of CO2 would cause climate change, the most severe predictions – some of which were adopted by the UN’s peak climate body in its seminal 2007 report – had been significantly overstated.

The authors used a novel approach based on modelling the effects of reduced CO2 levels on climate, which they compared with proxy-records of conditions during the last glaciation, to infer the effects of doubling CO2 levels.

They concluded that current worst-case scenarios for global warming were exaggerated.

“Now these very large changes (predicted for the coming decades) can be ruled out, and we have some room to breathe and time to figure out solutions to the problem,” the study’s lead author, Andreas Schmittner, an associate professor at Oregon State University, said.

Professor Schmittner said taking his results literally, the IPCC’s average or “expected” value of a 3C average temperature increase for a doubling of CO2 ought to be regarded as an upper limit. (source)

Wait for the warmists to start the smear campaign on that poor guy. And at the same time, more explosive Climategate emails show the extent to which uncertainty was minimised within the climate science community in order to avoid any possible damage to “The Cause”.

In one 2009 email exchange between British government advisers and climate scientists, including Professor Phil Jones from the University of East Anglia who was a key figure in the first Climategate saga, one adviser writes: “I can’t overstate the HUGE amount of political interest in the project as a message that the government can give on climate change to help them tell their story. They want the story to be a very strong one and don’t want to be made to look foolish.” The exchange concerns a project called Weather Generator that forecasts heatwaves and extreme rainfall events across Britain.

In a 2003 email to colleagues, the UEA’s Irene Lorenzoni writes: “I agree with the importance of extreme events as foci for public and governmental opinion.” (source)

Details have also emerged at the close relationship between those scientists and the BBC, confirming suspicions that the UK’s national broadcaster is acting as an environmental activist mouthpiece for climate alarmism:

Yes, glad you stopped this — I was sent it too, and decided to spike it without more ado as pure stream-of-consciousness rubbish. I can well understand your unhappiness at our running the other piece. But we  are constantly being savaged by the loonies for not giving them any coverage at all, especially as you say with the COP in the offing, and being the objective impartial (ho ho) BBC that we are, there is an expectation in some quarters that we will every now and then let them say something. I hope though that the weight of our coverage makes it clear that we think they are talking through their hats. (source)

“The objective impartial (ho ho) BBC”. Nudge nudge, wink wink. Ah, pity the poor Brits paying their TV licences for this kind of disgraceful bias. Little reason to doubt that the ABC is in a similar position – you only need to look at their output on climate matters to see that.


  1. Rather than use the last glaciation, they could have used the Medieval Warm Period and shown that CO2 causes cooling !
    As we know, CO2 has bugger all effect on climate.

  2. Surprisingly, even Dr. Andy Dressler, well known for his ‘warmist’ stance, had this to say about Andreas Schmittner’s paper on climate sensitivity, “The conclusion about the climate sensitivity is pretty consistent what most climate scientists think … I was not terribly worried about runaway climate change before this. After all, we know that the Earth’s had much higher CO2 in the past and the Earth did not turn into Venus.”

    Still it’s refreshing to read something from Andreas Schmittner – a scientist not involved with Climategate 1 or 2!

  3. Yup ! ” All the news that’s fit to …. suppress! “

  4. sillyfilly says:

    Hey Simon ,
    you missed some very salient points from the study: courtesy Science Daily:

    High sensitivity climate models — more than 6 degrees — suggest that the low levels of atmospheric CO2 during the Last Glacial Maximum would result in a “runaway effect” that would have left Earth completely ice-covered.

    “Clearly, that didn’t happen,” Schmittner said. “Though the Earth then was covered by much more ice and snow than it is today, the ice sheets didn’t extend beyond latitudes of about 40 degrees, and the tropics and subtropics were largely ice-free — except at high altitudes. These high-sensitivity models overestimate cooling.”

    On the other hand, models with low climate sensitivity — less than 1.3 degrees — underestimate the cooling almost everywhere at the Last Glacial Maximum, the researchers say. The closest match, with a much lower degree of uncertainty than most other studies, suggests climate sensitivity is about 2.4 degrees.

    What does the IPCC WG1 say:
    “likely to be in the range 2 to 4.5°C with a best estimate of about 3°C, and is very unlikely to be less than 1.5°C. Values substantially higher than 4.5°C cannot be excluded, but agreement of models with observations is not as good for those values.” Not a bad estimate from studies done at least 5 years ago.

    Moreover, it severely questions and ,if fact, completely disagrees with the low climate sensitivity arguments of Plimer, McLean, Carter, Monckton, Lindzen and maybe even Roy Spencer, all of whom have spruiked much less than 1.5DC. As a consequence, that probably puts paid to all the climate sensitivity studies done by the Galileo Movement, Global Warming Policy Foundation, Heartland Institute or any of the oxymoronic Climate Science Coalitions (so beloved of Bob Carter)

    Pity about that, eh!

    • Valiant attempt to defend “The (crumbling) Cause”. Well done!

      • sillyfilly says:

        The cause has effect: and the “madness” of the anti AGW/CC brigade crumbles at the feet of science. Pity that your continued polemics have little or no scientific justification. But that’s nothing usual!

        Thanks to Baldrick for his short list of some of those current and future effects.

        • Well, if you think “science” is the discipline of fudging data, suppressing uncertainties, intimidating journals, deleting emails and avoiding FOI requests in order to further a pre-conceived and politicised agenda, (which you obviously must do) then you’re probably right! It’s as if Climategate never happened! Nothing to see here, move along! LOL.

        • Ho hum!

    • sillyfilly you missed the most salient point from the study: courtesy Science Daily:
      “the most Draconian projections of temperature increases from the doubling of CO2 are unlikely.”

      And just what are those Draconian projections … Oceans acidifying – Glaciers Melting – Sea levels rising – More severe weather events – Malaria spreading – etc etc etc.

      All of which means words like these from the famous warmist Dr. James Hansen, NASA are nothing but garbage: “If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 389 ppm to at most 350 ppm.”

  5. A little off topic but perhaps this market news is truely the “Canary in the Coal mine”??

  6. “The cause” hey…. Two words
    confirmation bias.

  7. The report explicitly confirms the role of CO2 in the observed warming of the planet, so I suppose that if you accept the finding on sensitivity, that you also accept the rest of the study’s findings? Or is that too inconvenient for you? Ideology is a hell of a thing to deal with.

  8. [snip] Go away and don’t come back, and take your patronising garbage comments with you. You don’t even have the guts to provide a genuine email address. Troll.

  9. This study admittedly doesn’t model clouds, which are a likely negative feedback. Get ready for an admission of 1°C or less in the next 5-10 years.

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