Climate Science Rapid Response Team can't tell the truth on sea level paper

Climate Science Watch posted on 17th. Dec. 2012; Sea level rise study misrepresented; humans still raising sea level

There is a new paper out in the Journal of Climate which some have hailed as proof that the global mean sea level is not influenced by human activity. However, this is exactly the opposite of what the study authors explain are the real results.

The following guest post is a briefing note by the Climate Science Rapid Response Team:

The study finds sea level rise is still continuing at a steady rate. Study author Dr. John Church has stated via email correspondence, “I would argue that there is an unhealthy focus on one single statistic -- an acceleration number -- and insufficient focus on the temporal history of sea level change.” 

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With a complete reading of the paper, it becomes apparent that acceleration is only one part of the larger picture. The planet is rapidly warming and the seas are rising. These researchers are refining our understanding of which factors are driving that rise, and in what proportions.

The study Twentieth-century global-mean sea-level rise: is the whole greater than the sum of the parts? indeed finds that "sea level rise is still continuing at a steady rate".

Abstract

Confidence in projections of global-mean sea-level rise (GMSLR) depends on an ability to account for GMSLR during the 20th century. There are contributions from ocean thermal expansion, mass loss from glaciers and ice sheets, groundwater extraction and reservoir impoundment. We have made progress towards solving the “enigma” of 20th-century GMSLR—that is, the observed GMSLR has been found to exceed the sum of estimated contributions, especially for the earlier decades. We propose that: thermal expansion simulated by climate models may previously have been underestimated owing to their not including volcanic forcing in their control state; the rate of glacier mass loss was larger than previously estimated, and was not smaller in the first than in the second half of the century; the Greenland ice-sheet could have made a positive contribution throughout the century; groundwater depletion and reservoir impoundment, which are of opposite sign, may have been approximately equal in magnitude. We show that it is possible to reconstruct the timeseries of GMSLR from the quantified contributions, apart from a constant residual term which is small enough to be explained as a long-term contribution from the Antarctic ice-sheet. The reconstructions account for the approximate constancy of the rate of GMSLR during the 20th century, which shows small or no acceleration, despite the increasing anthropogenic forcing. Semi-empirical methods for projecting GMSLR depend on the existence of a relationship between global climate change and the rate of GMSLR, but the implication of our closure of the budget is that such a relationship is weak or absent during the 20th century.

Note that last sentence and read the distorted logic and back-pedalling in the comments. One of the "Rapid response Team (RRT)" (equipped with hockey-stick maybe?), Dr. John Abraham ends his comment

In short, saying that the relationship between global climate change and sea level rise is weak is not the same as saying “climate change has nothing to do with sea level rise."

Well, no - the abstract says "weak or absent". Apparently "absent" is absent from Dr. Abraham's vocabulary. John Church, co-author of many sea-level papers cited in many reports including IPCC assessment reports and a co-author on this particular paper says

I basically agree with what John Abraham has written.

Sea level is more complex then just a simple linear relationship to surface temperatures. The physics is more complex than this and there are multiple time scales for each of the components contributing to sea level change. Glaciers are a good example. As temperatures continue to rise their contribution cannot continue to rise indefinitely because over time there will be a smaller glacier volume to contribute to sea level rise

I see a "straw man" surfacing from the rising waters - who on the CSW page or elsewhere mentioned "a simple linear relationship to surface temperatures"? No -one, though perhaps Abraham would say "it's not the same as saying there aren't any such statements".

Fundamentally, the "rapid-response team" is saying that "Semi-empirical methods for projecting GMSLR depend on the existence of a relationship between global climate change and the rate of GMSLR, but the implication of our closure of the budget is that such a relationship is weak or absent during the 20th century" doesn't mean what it so clearly does say. Even one of the co-authors "basically agree[s] with what John Abraham has written". Is he telling us that the abstract is in error? If so why hasn't it been corrected?

I, as a sceptical observer, would observe that if the correlation between climate change and sea-level rise in the 20th. century is "weak or absent", and that if climate change over that period is hypothesised to be driven by human activities, then the claimed correlation between those activities and sea-level rise is also "weak or absent". But then, I'm not a scientist, and not qualified to comment on a statement in a research paper which one of the authors agrees doesn't say what it clearly does say.

The RRT also says "this is exactly the opposite of what the study authors explain are the real results". How many authors explained "the real results"? Just the one, apparently. Big numbers are clearly not the RRT's strongest suit.

But what about the RRT statement "The planet is rapidly warming" and the comment from co-author John Church "As temperatures continue to rise"? - IPCC AR5 and any temperature dataset refute both of those claims (I'm being tactful using the word). Perhaps they'd both say that a chart which shows stasis or a slight fall in temperature during the 21st century "is not the same as saying there's no global warming" over the same period. "Post-normal science" is all around us, and rising rapidly.

IPCC AR5 - is the truth finally slipping out?

WG1 chapter 1 contains the following graphic (click to enlarge)

Figure 1.11: Estimated changes in the observed global annual sea level since 1990. Estimated changes in global annual sea level anomalies from tide gauge data (Church and White, 2011; available at http://www.cmar.csiro.au/sealevel/sl_data_cmar.html) (black error bars showing 1s uncertainty) and based on annual averages from TOPEX and Jason satellites (Nerem et al., 2010; available at http://sealevel.colorado.edu/results.php) (blue dots) starting in 1992 (the values have been aligned to fit the 1993 value of the tide gauge data). The shading shows the largest model projected range of global annual sea level rise from 1990 to 2015 for FAR (Scenario D and business-as-usual), SAR (IS92c and IS92e), TAR (A2 and A1FI) and for Church et al. (2011) based on the CMIP3 model results available at the time of AR4 using the SRES A1B scenario.

A couple of things immediately struck me; first that the blue dots (annual average from TOPEX and JASON) show a tailing-off on the right (2011) to almost exactly 5cm above the 1993 value of a smidgen (that's a technical term used by us statistical experts [ha! - ed.] for a very small quantity) above zero. That gives 5/19 = 0.263 or 2.63 mm/year, rather less than the 3.2 mm/year over the satellite era (since the beginning of 1993) we've been fed to date. In order to get that 3.2 rate, the 2011 value would have to be 6cm above that for 1993 which clearly it's not. I think they've got a cheek assigning a zero value to 1992; observations didn't start until well into the latter half of that year.

Small potatoes maybe but is the truth (or something approaching the truth) finally slipping out?

'Extreme climate may wipe out mammals from Earth' - or maybe not

The Business Standard intones dramatically

Mammals could be at greater risk of extinction due to a higher frequency of extreme conditions such as cyclones and droughts spurred by climate change, scientists have warned.

Researchers from the Zoological Society of London (ZSL) have mapped out land mammal populations, and overlapped this with information of where droughts and cyclones are most likely to occur. This allowed them to identify species at high risk of exposure to extreme weather.

The study describes the results of assessing almost six thousand species of land mammals in this way.

Bear in mind that land mammals have been exposed over millions of years, to more than one ice age with "extreme weather" (of the cold-induced variety) and at least one interglacial period during which temperatures were several degrees above those of today with "extreme weather" (of the heat-induced variety).

"Approximately a third of the species assessed have at least a quarter of their range exposed to cyclones, droughts or a combination of both," lead author of research, Eric Ameca y Juarez said.

"If these species are found to be highly susceptible to these conditions, it will lead to a substantial increase in the number of mammals classified as threatened by the IUCN under the category 'climate change and severe weather'," said Juarez in a statement.

In particular, primates - already among the most endangered mammals in the world - are highlighted as being especially at risk.

Just a minute though - "If these species are found to be highly susceptible to these conditions" implies, nay states, that the zoologists haven't actually assessed the vulnerability of land mammals to "extreme weather". Neither it seems, have they assessed the actual probability of the extremes they "predict", nor the extent or intensity of the extremes, nor specified the timescales over which those extremes might occur.

"This is the first study of its kind to look at which species are at risk from extreme climatic events. There are a number of factors which influence how an animal copes with exposure to natural disasters.

"It is essential we identify species at greatest risk so that we can better inform conservation management in the face of global environmental change," ZSL's research fellow Dr Nathalie Pettorelli said.

What does AR5 draft have to say about cyclones? Ch2 FAQ 2.2 says

Considering other extremes, such as tropical cyclones, the latest assessments show low confidence that any reported long-term increases in tropical cyclone activity are robust, after accounting for past changes in observing capabilities. There is some evidence, however, of an intensification of the most extreme storms, but records are currently very short.  

Over periods of a century or more, evidence suggests slight decreases in the frequency of tropical cyclones making landfall in the North Atlantic and the South Pacific, once uncertainties in observing methods have been considered. Little evidence exists of any longer-term trend in other ocean basins.

So much for the "increase in hurricanes/cyclones" meme touted as fact lately. What about droughts? Section 2.6.2.2 Floods, Droughts and Severe Local Weather Events:

On the whole the annual maximum number of consecutive dry days appears to be declining in most regions since the 1950s (Figure 2.33b). Using a measure which combines both dry spell length and precipitation intensity Giorgi et al. (2011) indicate that ‘hydroclimatic intensity’ (Chapter 7) has increased over the latter part of the 20th Century in response to a warming climate. They show that positive trends are most marked in Europe, India, parts of South America and East Asia although trends appear to have decreased in Australia and northern South America (Figure 2.33c). Data availability, quality and length of record remain issues in drawing conclusions on a global scale, however.

So where there are trends in tropical cyclones (includes hurricanes) they show decreased frequency - something many sceptics have been saying for years - based on the data. With regards to drought, "On the whole the annual maximum number of consecutive dry days appears to be declining in most regions since the 1950s".

Every so often, more often year on year it seems, I read of some "research" or other that produces an immediate reaction of "what a load of crap". This study is one such.

Permafrost - the bottom line

In a recent post UNEP Report - Policy Implications of Warming Permafrost I identified a major contradiction therein, and debunked claimed "increases" in CO2 and methane over permafrost areas. I've been digesting parts of the leaked IPCC AR5 draft report, and found this in WG1 chapter 6:

6.3.3.2 Emissions 

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Over the past decades, however, there is no evidence for significant emission of CH4 from permafrost and hydrates (Dlugokencky et al., 2009). 

.... from the horse's mouth.

And a little further on this section:

6.4.3.4 Permafrost Carbon

Current estimates of permafrost soil carbon stocks are 1670 PgC (Tarnocai et al., 2009), the single largest component of the terrestrial carbon pool and higher than previously thought. Terrestrial carbon models show a land CO2 sink with warming at high northern latitudes, however none of the models participating in C4MIP or CMIP5 included explicit representation of permafrost soil carbon decomposition, which at a minimum requires sufficient vertical resolution in modelled soil carbon distribution and processes to separate surface pools from very old (Pleistocene) permafrost carbon pools. Including permafrost carbon processes into an ESM can change the sign of this C response to warming from a sink to a source in northern high latitudes (Koven et al., 2011). The magnitude of this source of CO2 to the atmosphere from decomposition of permafrost carbon varies widely by 2100 according to different model estimates: process-model estimates include 7–17 Pg (Zhuang et al., 2006), 55–69 Pg (Koven et al., 2011), and 126–254 Pg (Schaefer et al., 2011); estimates of uncertainty ranges suggest the source could range from 33 to 114 Pg C (68% range) under RCP8.5 warming (von Deimling et al., 2012), or 50–270 PgC (5th–95th percentile range; Burke et al., subm.). Combining observed vertical soil C profiles with modelled thaw rates estimate that the total quantity of newly-thawed soil C by 2100 will be 246 Pg for RCP4.5 and 436 Pg for RCP8.5 (Harden et al., 2012 in press). Sources of uncertainty for the permafrost C feedback include the physical thawing rates, the fraction of C that is release after being thawed and the timescales of release, possible mitigating nutrient feedbacks, and the role of fine-scale processes in determining the terrestrial response. 

Note the model results for emissions from permafrost to 2100: 7–17 Pg (petagrams), 55–69 Pg, 126–254 Pg, and the consequent estimated uncertainty range of 33 to 114 Pg C or 50–270 Pg C at the 5th–95th percentile range. What does this all mean?

They don't know.