Updated climate sensitivity estimates using aerosol-adjusted forcings and various ocean heat uptake estimates

The Otto et al. paper has received a great deal of attention in recent days. While the paper’s estimate of transient climate response was low, the equilibrium/effective climate sensitivity figure was actually slightly higher than that in some other recent studies based on instrumental observations. Here, Nic Lewis notes that this is largely due to the paper’s use of the Domingues et al. upper ocean (0–700 m) dataset, which assesses recent ocean warming to be faster than other studies in the field. He examines the effects of updating the Otto et al. results, extending from 2009 to 2012 and using different upper ocean (0–700 m) datasets, with surprising results.

Last December I published an article here entitled ‘Why doesn’t the AR5 SOD’s climate sensitivity range reflect its new aerosol estimates?‘ (Lewis, 2012). In it I used a heat-balance (energy-budget) approach based on changes in mean global temperature, forcing and Earth system heat uptake (ΔT, ΔF and ΔQ) between 1871–80 and 2002–11. I used the RCP 4.5 radiative forcings dataset (Meinshausen et al, 2011), which is available in .xls format here, conformed it with solar forcing and volcanic observations post 2006 and adjusted its aerosol forcing to reflect purely satellite-observation-based estimates of recent aerosol forcing.

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A whiff of the Sunday Sport

Having failed to reply to Matt Ridley's request to respond to Myles Allen's critique, Damian Carrington and his band of merry men have responded with another, but rather grubbier, attack in the same direction, this time from Nuccitelli.

Given that even Nuccitelli's co-authors at Skeptical Science have pointed to his misrepresenting those who disagree with him, and given the car crash of his article about Nic Lewis the other day, a reputable newspaper would steer clear. But when you haemorrhaging money, I guess the priorities are different.

Here's a paragraph from Nuccitelli's article:

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Electricity prices

No comment required.

The amazing meeting

The Global Warming Policy Foundation has taken Paul Nurse up on his suggestion that they get together with some top climatologists to discuss climate science, and has issued formal invititations (press release and further details here). The proposed agenda looks interesting too:

1. The science of global warming, with special reference to (a) the climate sensitivity to carbon dioxide and (b) the extent of natural variability;

2. The conduct and professional standards of those involved in the relevant scientific inquiry and official advisory process.

Pass the popcorn.

Oxford professors and the poor

Yesterday Myles Allen posted a highly personal attack on Matt Ridley. The Guardian has apparently failed to respond to Matt's requests to allow him to respond (I am reminded of their publication of Bob Ward's hit piece on me back in 2009, when it took days to get them to reply to me and weeks before the response was published). This being the case Matt has asked me to post the following:

Dear Professor Allen,

In your polemical Guardian article on Tuesday you produce no counter-arguments to my Times article. For example, you ask: "Is Ridley right that there is no actual evidence of harm as long as droughts, floods and storms are within historic variability?" You then do not answer that question. Well, am I right or not?

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Donoughue fights on

Lord Donoughue continues his lonely struggle to get peers of the realm to give the time of day to people struggling under the burden of UK energy policy. His speech in Lords last week is well worth a read.

Last week, a global warming campaigner from this House denounced those who question green orthodoxy as, revealingly, the “forces of darkness”. I say revealingly because the language is religious or religiose. Much of this debate is conducted in those terms. The greens claim the high moral ground, pursuing the virtue of—ambitiously, I must say—saving the planet. “The end of the world is nigh”, they say. Those of us who question them are evil sinners.

Lateral thinking

The Institute of Directors has issued a report on shale gas, saying that it could create tens of thousands of jobs in areas that desperately need them.

Shale gas development could create tens of thousands of jobs, reduce imports, generate significant tax revenue and support British manufacturing. The Institute of Directors’ comprehensive new report, Getting shale gas working, studies the lessons of previous energy developments, investigates the economic impacts of potential shale gas production at scale, and sets out the practical steps for both government and industry to overcome the key barriers.

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Hansen at the LSE

Reader Danny Weston sends this report of James Hansen's lecture at the LSE last week.

On Friday the 17th James Hansen came to speak at the London School of Economics (LSE), on “Itinerant farming to White House arrests: A scientist’s view of the climate crisis”.

The venue was completely packed and I wasn’t sure initially if I would even get in. There were hundreds of people, already buzzing with excitement before Hansen began his talk.

As expected, Hansen put the frighteners on, emphasising that immediate action was required to stymie anthropogenic CO2’s allegedly noxious effect on our environment. His presentation was littered with continual emotive references to, and pictures of, his numerous grandchildren, showing them gradually growing up. This was important because Hansen is now pushing the line that whilst climate catastrophe is not imminent, it is “in the pipeline” and the victims will, apparently, be our grandchildren. The reason we’re not seeing imminent catastrophe now is because of “climate inertia” and we should be worried because there are further “tipping points” to come after which “we could lose control”. I’m sure all of this sounds familiar.

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IoP and the great unwashed

The Institute of Physics Environmental Physics group seems to be very pressed for time at the moment. While meetings are usually announced well in advance, the organisers of the next event, the members day meeting on 22 May, seem to have left things until the last minute. The notice, which, from the document properties, was prepared by Simon Buckle of the Grantham Institute at Imperial, was only sent out yesterday evening. How unfortunate!

This is not the only oddity either. The group's events have previously been open to all comers - the IoP is a registered charity after all, so allowing the public to attend is part of their mission of public education. I hear, however, that for the latest event,  those who are thinking to go along have been advised to bring their membership cards. It appears that the great unwashed are no longer wanted. Will the IoP be turning the public away at the door? What would the Charities Commission say?

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ECS with Otto

Further to the last posting, and in particular the claim in the BBC article that the 2-4.5 range is largely unaffected by the Otto et al paper, here's my graph of ECS curves with the incorporation of the Otto et al results - both the full-range and the last-decade curves. These are shown in black.  As previously, the other studies are coloured purple for satellite period estimates, green for instrumental, and blue for paleoestimates. The grey band is simultaneously the IPCC's preferred range and the range of the climate models.

As you will see, it is fairly clear that the Otto et al results slot in quite nicely alongside the other recent low-sensitivity findings, with most of the density outside the range of the models. The IPCC's preferred range looks increasingly untenable.

Reactions to Otto et al

Updated on May 20, 2013 by Bishop Hill

Updated on May 20, 2013 by Bishop Hill

Updated on May 20, 2013 by Bishop Hill

Press reactions to the Otto et al paper vary from the sublime to the ridiculous.

Matt Ridley in the Times (£) points to the policy implications and notes that mitigation now looks like a pretty daft approach to take:

It is true that the “transient climate response” is not the end of the story and that the gradual warming of the oceans means that there would be more warming in the pipeline even if we stopped increasing carbon dioxide levels after doubling them. But given the advance of nuclear and solar technology, there is now a good chance we will have decarbonised the economy before any net harm has been done.

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New energy-budget-derived estimates of climate sensitivity and transient response in Nature Geoscience

This is a guest post by Nic Lewis. Please note that although the embargo on the paper was lifted at 6pm, at time of writing the paper itself had yet to appear on the Nature website. It should be at the link given below in the near future.

Readers may recall that last December I published an informal climate sensitivity study at Bishop Hill, here. The study adopted a heat-balance (energy budget) approach and used recent data, including satellite-observation-derived aerosol forcing estimates. I would like now to draw attention to a new peer-reviewed climate sensitivity study published as a Letter in Nature Geoscience, "Energy budget constraints on climate response", here. This study uses the same approach as mine, based on changes in global mean temperature, forcing and heat uptake over 100+ year periods, with aerosol forcing adjusted to reflect satellite observations. Headline best estimates of 2.0°C for equilibrium climate sensitivity (ECS) and 1.3°C for the – arguably more policy-relevant – transient climate response (TCR) are obtained, based on changes to the decade 2000–09, which provide the best constrained, and probably most reliable, estimates. The 5–95% uncertainty ranges are 1.2–3.9°C for ECS and 0.9–2.0°C for TCR. I should declare an interest in this study: you will find my name included in the extensive list of authors: Alexander Otto, Friederike E. L. Otto, Olivier Boucher, John Church, Gabi Hegerl, Piers M. Forster, Nathan P. Gillett, Jonathan Gregory, Gregory C. Johnson, Reto Knutti, Nicholas Lewis, Ulrike Lohmann, Jochem Marotzke, Gunnar Myhre, Drew Shindell, Bjorn Stevens, and Myles R. Allen. I am writing this article in my personal capacity, not as a representative of the author team.

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This house would stop the annual UN climate summits

The Oxford Energy Society is to hold a rather interesting debate on 28 May. The motion, 'This house would stop the annual UN climate summits' is interesting enough, but take a look at the two teams:

Proposition

Dr Benny Peiser
Director, Global Warming Policy Foundation

David Rose
Writer, The Mail on Sunday

Prof Myles Allen
Leader, ECI Climate Research Programme

Opposition

David Symons
Director, WSP Environment and Energy

Fiona Harvey
Environmental Journalist, The Guardian

Dr Chukwumerije Okereke
Reader in Environment & Development, University of Reading

That should set the cat among the pigeons.

More critical science journalism required

Jalees Rehman, a medical professor from the US, reckons we need more critical science journalism.

Critical science journalism takes a different approach and focuses on providing a balanced assessment of the work, one that highlights specific strengths but also emphasises specific limitations or flaws. It is no big secret that the majority of research findings published in peer-reviewed scientific journals will probably not hold up when other groups attempt to replicate them. This lack of replicability can be due to research misconduct, systematic errors or other cognitive biases, which commonly occur even in the most conscientious and meticulous scientists.

Therefore, critical science journalism requires a careful analysis of all the data presented in a paper and is likely to uncover key limitations and flaws that scientific researchers themselves do not readily divulge. This form of science journalism can also encompass some degree of investigative journalism. Journalists lack the resources to check the validity of scientific data by performing experiments themselves, but they can track scientific research in a certain area over the course of months and years as multiple research groups attempt to replicate published scientific findings.

In the climate debate, critical commentary is of course par for the course, at least among the blogs. It's the newspapers that feel they have to act as cheerleaders, usually because the journalists have no scientific background and therefore struggle with any kind of critique.

Happer on CNBC

William Happer recently appeared on CNBC's Squawkbox show, discussing the 400ppm story.