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Poker Betts - Josh 288

Richard Betts quotes Dr Wallace Broecker, "The climate system is an angry beast and we are poking it with sticks." Read here.

As has been observed, it looks like it is not a very big stick and/or the climate is in good humour.

Cartoons by Josh


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Reader Comments (59)

This is a very interesting discussion.

However, all the nuancing of expressions of uncertainty is only part of the story - it's how different people respond to the uncertainty which is the really key point.

Some think we need more certainty before we decide what to do. Others think we should hedge our bets. It's a judgement call.

Sep 2, 2014 at 12:21 AM | Registered CommenterRichard Betts

Don Keiller

I put some discussion and a request for more detail on Humluma wt all on the Arctix Ice is Up thread.

Sep 2, 2014 at 12:27 AM | Unregistered CommenterEntropic man


Judgement on action under certainty is indeed the core issue, and one where climate scientists have no special authority or insight, which makes it extraordinary that some climate scientists are quite so publicly disappointed about the "failure" of governments to act on their concerns.

It also means that it is vital that bodies like the Met Office are crystal clear about the level of uncertainty and describe it in simple and straightforward terms. That means being open and upfront about terms like "best guess", rather than tucking the uncertainty behind the sofa in the hope that nobody will notice.

I am well aware that like all scientists you are under huge pressure to overstate the certainty of what are in reality highly provisional findings, but academics have a duty to resist such pressures and to tell people what's really going on.

Sep 2, 2014 at 8:01 AM | Registered CommenterJonathan Jones

Jonathan Jones

Climate scientists are professionally very reluctant to discuss the policy imp!ications of their work. That is the politician's job.

However a scientist is also a citizen, with a right to an opinion and a voice. Would you argue that any professional should be banned from discussing anything of which they have professional knowledge. Should accountants be banned from discussing the Budget?

Sep 2, 2014 at 8:43 AM | Unregistered CommenterEntropic man

You can replace all JJ's text with just the simple statement that 'we don't know enough to say anything at all but we can keep pretending that we do because we are never held accountable for being wrong all the time.'

As for models having 'best guesses'; far from it, they were actually very pessimistic guesses that maintained a politically-motivated high CO2 sensitivity only by dint of grossly unscientific assumptions about manmade aerosols and natural variation.

Betts keeps repeating the false equivalence fallacy of uncertainty going both ways yet increasing sensitivity is decreasingly likely by the known physics & basic common sense and carbon dioxide is conclusively not a driver of climate by the experimental findings of adding a large slug of CO2 to the atmosphere and seeing nothing happening. Even if that was not enough to slay the notion of high potential CO2 sensitivity, previous science-based scares reveal a repeating pattern of scientists extrapolating wildly from very little real data and then being proven wrong by mother nature. Plus ca change, plus la meme chose!

Sep 2, 2014 at 9:07 AM | Unregistered CommenterJamesG

Richard Betts

would you accept that the MO has been overconfident in many of its statements going back in time and it is only in the very recent past that the 'uncertainty monster' has been allowed to be heard?

and following on, do you think policy makers have been made sufficiently aware of this shift?


Sep 2, 2014 at 9:26 AM | Unregistered CommenterH2O: the miracle molecule

Hi Jonathan

It's a bit odd that you claim that I am 'tucking the uncertainty behind the sofa in the hope that nobody will notice'

This whole series of posts came about because I said:

Everyone** agrees that we can’t predict the long-term response of the climate to ongoing CO2 rise with great accuracy. It could be large, it could be small. We don’t know.

Which part of 'We don't know" is not clear enough for you? ;-)

OK I guess you could argue that nobody of any influence reads this blog, so what I say here is of little consequence, so maybe we could look at what I say in more high-profile publications such as Nature. I was a co-author on Ed Hawkins' Comment 'Uncertainties in the timing of unprecedented climates' which took apart the Mora et al Nature paper which made over-confident claims. We said:

their methodology produces artificially early dates at which specific regions will permanently experience unprecedented climates and artificially low uncertainty in those dates everywhere. This overconfidence could impair the effectiveness of climate risk management decisions

Or maybe you can argue that the peer-reviewed literature isn't read by governments, so lets look at what I say in reports directly to the government. How about my report with Doug McNeall for the 'Migration and Global Environmental Change' study, in which we called out the Oxfam and Global Humanitarian Forum claims of increases in disasters due to climate change - we said:

These statements appear to unsubstantiated by rigorous science.

and also pointed out shortcomings in the IPCC 4th Assessment Report:

Reconstructions of historical soil moisture using data and models suggest an overall small wetting trend globally, in contrast to the assessment of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report that the total area affected by drought is ‘likely’ to be increasing.

I could give other examples, but I think you get the point that I reject the accusation that I overstate certainty, whether in public blogs, peer-reviewed literature or direct advice to government.

Sep 2, 2014 at 11:50 PM | Registered CommenterRichard Betts

Richard Betts

"their methodology produces artificially early dates at which specific regions will permanently experience unprecedented climates and artificially low uncertainty in those dates everywhere"

Your statement accepts that permanently unprecedented climate will occur, you are simply arguing when. What is your validated evidence for this acceptance?

If I have misinterpreted your position, I would be grateful for your comment/correction

Sep 3, 2014 at 9:54 AM | Unregistered CommenterRonaldo

Ronaldo +1

Sep 3, 2014 at 3:46 PM | Unregistered Commenternot banned yet

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