Arguments
Matt Ridley Risk Management Failure Deja Vu
Posted on 22 December 2012 by dana1981
Matt Ridley has published another article in a mainstream media source, this time the Wall Street Journal (WSJ), which has a long history of publishing climate contrarian nonsense. This article is not very different from his previous piece in WIRED magazine, and has already been debunked quite effectively by Climate Progress and Media Matters. However, there is a very simple explanation as to where Ridley has gone fundamentally wrong; it's the same mistake he made in WIRED and in his professional banking career — Ridley still fails to understand basic risk management and wants to wager the future of the Earth's climate on a flimsy argument.
Ridley Makes a Weak Case
The crux of Ridley's article is that he believes climate sensitivity (the total amount the Earth's surface will warm in response to the increased greenhouse effect, including amplifying and dampening feedbacks) is low. To support this argument, Ridley references a few studies which find that climate sensitivity is on the lower end of the range of likely values published in the most recent Intergovernmental Panel on Climate Change (IPCC) report, as well as a blog post written by financier Nic Lewis. We may examine Lewis' argument in a separate blog post, but since it has not been subjected to the peer-review process or published, it is not a very credible or convincing reference.
That's really all there is to it. Ridley believes that climate sensitivity is low based on a couple of cherrypicked studies (and what his financier friend wrote on some blog), and therefore the planet will not warm too terribly rapidly over the next century, and therefore we have nothing to worry about.
Ridley's Rose-Colored Glasses
Unfortunately if the worst case (or even most likely case) climate scenario comes to fruition, there will be nobody to bail out the planet.
It is certainly possible that climate sensitivity is on the low end of the possible range of values (discussed in more detail below), although we would still have to take serious steps to prevent human greenhouse gas emissions from rising so much that even a low sensitivity scenario would result in extremely dangerous levels of global warming. However, only considering the best case scenario — which is precisely what Ridley is advocating for in WSJ and WIRED — neglects the scenarios in which climate sensitivity is not low. If we proceed under the assumption that the best case scenario is true, but it turns out that climate sensitivity is actually not near the lowest possible values, then we will be on a path for catastrophic climate change.
This approach is very similar to the one Ridley took as the non-executive Chairman of Northern Rock, a British bank that, in 2007, was the first in over 150 years to experience a run on its deposits. The bank had allowed itself to become extremely over-leveraged, with debts more than 50 times its shareholder common equity. Ultimately Northern Rock was bailed out, borrowing £3 billion from the Bank of England over the span of a few days in 2007. Ridley was unprepared for the worst case scenario when it came to fruition. Unfortunately if the worst case (or even most likely case) climate scenario comes to fruition, there will be nobody to bail out the planet.
Ridley Cherrypicking
Knutti and Hegerl (2008) presents a comprehensive overview of our scientific understanding of climate sensitivity. In their paper, they present a figure which neatly encapsulates how various methods of estimating climate sensitivity examining different time periods have yielded consistent results. As you can see, the various methodologies are generally consistent with climate sensitivity in the range of 2 to 4.5°C global surface warming resulting in response to a doubling of atmospheric CO2, with a most likely value of 3°C.
Figure 1: Distributions and ranges for climate sensitivity from different lines of evidence. The circle indicates the most likely value. The thin colored bars indicate very likely value (more than 90% probability). The thicker colored bars indicate likely values (more than 66% probability). Dashed lines indicate no robust constraint on an upper bound. The IPCC likely range (2 to 4.5°C) is indicated by the vertical light blue bar.
These results include a variety of different approaches, including studies looking at past historical climate changes, recent changes, and climate model simulations. A project called PALEOSENS recently published a paper in the journal Nature which estimated climate sensitivity based on climate changes over the past 65 million years. Their results are similar to the range in the Knutti and Hegerl study, as well as the IPCC, with a likely range of 2.2 to 4.8°C global surface warming in response to a doubling of atmospheric CO2.
Ridley's case is based on a climate sensitivity of even less than 2.2°C, which means that it is a very optimistic and very unlikely scenario. He has essentially cherrypicked a few studies with the lowest climate sensitivity estimates, and brought in some unvetted blog 'science' by a financeer, while ignoring the vast majority of the body of peer-reviewed climate sensitivity literature.
Ridley Deja Vu All Over Again
Ridley's WSJ piece repeats many of the same mistakes in his WIRED piece — cherrypicking the best case scenario, ignoring the enormous risks if his climate optimism is misplaced, and defending his position with wrong arguments (e.g. claiming that the water vapor feedback is weak, when we know from empirical observational data that water vapor provides a strong amplifying feedback). The failure to take a prudent risk management approach is also a repeat of Ridley's mistakes in the banking industry. Reading Ridley's WSJ piece is like deja vu all over again.
Ridley has simply cherrypicked the most convenient scientific papers to support his optimistic view, ignored the vast majority of the scientific literature, and essentially argued that if we are very lucky, we may avoid catastrophic climate change.
It's true that if climate sensitivity is toward the low end of possible values, and if we manage to successfully reduce human greenhouse gas emissions, we may avoid very dangerous climate change. But what if climate sensitivity isn't on the low end? It is at least as probable that it could be on the high end of possible values, as a recent study by Fasullo and Trenberth (2012) suggests may be the case. If we bank (pardon the pun) on Ridley's optimism and it turns out to be unfounded, we will be on a path headed towards catastrophe. This is a scenario which Ridley consistently refuses to consider, despite the fact that this approach has previously come back to bite him.
A prudent risk management approach involves considering all possible scenarios and preparing for the worst. The worst case scenario here results in climate catastrophe, and we must try to prevent this scenario from occurring by reducing human greenhouse gas emissions. Ridley's approach is an ill-advised gamble, and boils down to one simple question — do you feel lucky? And even if you do, are you willing to gamble with the well-being and security of future generations?
Attacks on the messenger but the message escapes unscathed. Rightly so becuse he stuck to facts. Although Ridley is not a botanist his botanical arument was totally correct.
Hi Roger @30,
Care to put some detail into that claim? Given all of the nonsense Ridley has spouted in the past, I would be surprised if he got something right, but it's always interesting to hear the argument.
Leto.
Ridley's initial claim is that the earth is getting greener and he presented good evidence for that. Do you wish to dispute that point?
He also claimed that the increase in atmospheric carbon dioxide contributed to that greening arguing, on correct botanical grounds, that carbon dioxide is plant food.
Do you wish to dispute that point? Are there any point in his talk that you would like to dispute? If so what are they?
Ferns, cycads, horsetails and the like evolved in palaeozoic times with far higher levels of carbon dioxide in the atmosphere. Most of the evolution of the angiosperms, at least to generic and family level, had taken place before the end of Jurassic times, also in an atmosphere much richer in carbon dioxide. The level of carbon dioxide in the atmosphere today is sub-optimal for most plants. This is of course a fact well known to the operators of commercial greenhouses. It is no surprise really, and to be expected, that the increase in atmospheric carbon dioxide in recent decades has stimulated plant growth.
Should the inane pleas for reduction in atmospheric carbon dioxide actually succeed plant growth will slow and starvation will become the norm in much of the third world. Should we be entering a mini ice age, which is a distinct possibility given the lacl of warming for over a decade and the low level of sunspot activity, we might just need all the carbon dioxide we can get into the atmosphere!Roger Dewhurst @ 33, your claims seem to be extraordinary and require extraordinary proofs. For a quick review, I recommend having a look at the following articles here:
Hi Roger,
When I asked for details, I was wondering whether Ridley had mounted any sort of sophisticated botanical argument of relevance to the science of climatology. If you can't answer without mentioning fears of a mini-ice age and mass starvation on the back of "lacl of warming for over a decade", or without dismissing concerns about AGW as "inane", it does give me some idea of the audience he is pitching to, at least.
Comment policy on this site prevents me from saying much more of what I think, so I'll leave it at that. Some of the more patient folk here at SkS might be ready to discuss your ideas with you.
I'm not sure you've done Ridley any favours here.
Leto.
Roger Dewhurst - your comments are on the wrong thread. See: Ridley, Murdoch and Lomborg Attempt to Greenwash Global Warming.
Given the prior analyses of satellite greening show opposing trends what is so special about the latest as-yet-unpublished study? See you over at the other thread.