The play by Rolin Jones “The Intelligent Design of Jenny Chow” is a tale of science fueled by post-adolescent angst with a brilliant young woman who excels at rocket science but canâ€™t leave her bedroom. Driven by a real life quest to find her biological mother, she pilfers parts from her government rocket project and builds a replica of herself, named Jenny Chow to meet her real birth mother in China, by proxy.
Jenny’s robot is contemporary version of the Simulacrum, that creation of device for a purpose in a parody of reality. Such appears to be the case of the ‘hockey stick graph’ — a reconstruction of Millennial global temperatures based on tree-ring and other proxies by MBH98. The graph, showing temperatures relatively stable throughout the middle ages and recent times, and shooting upward suddenly last century has been an iconic feature of the IPCC 2001 report on climate change, and countless government reports, slide shows, powerpoints and papers since its invention.
Now, the report of the National Academy of Sciences on ‘Surface Temperature Reconstructions for the Last 2,000 Years‘ relates an overselling — an irrational exuberance — for the reconstruction by the IPCC in the summary for policy-makers.
The graph has become the Simulacra envisioned by Baudrillard.
- stage 1: the model is created in resemblance of the original reality
- stage 2: the model is reproduced by others with no reference to the original reality
- stage 3: models becomes the reality
Some excerpts from the NAS briefing:
“Greater variability in past climate may mean temperature is more sensitive to GHGs or be ameliorated. It could be either.”
“We are in the warmest period of the last 400 years.”
“We do agree with the substance of the finding (of MBH98). There is a disagreement with how sure we are about the period before 1600AD.”
“The MBH98 study underestimated those uncertainties (of the Medieval period).”
“While the conclusion is plausible, we don’t know if its true that individual years like 1998 were the warmest in the millennium.”
That the shape of recent warming is incorrect is not the subject of criticism of MBH98. The issue is the representation of past variability, that MBH98 illustrated as very small, relative to the present day.
The magnitude of past climate is important to the present. As Hegerl et.al. has showed, greater past variability entails more partitioning of present variation to solar origins, and less to GHGs, resulting in lower estimates of sensitivity to CO2. Clearly the report has less confidence in the Mann theory of less overall variability. Similarly, the statement that we can only confidently conclude that current temperature is the warmest in 400 years, is a remarkable pullback from exaggerated claims that temperatures now are the warmest in 1000, 10,000 or million years as have been made.
The paradigm that Medieval warm period is ‘murky’ or incoherent that the report is promulgating was strongly challenged at the end, numerous papers from numerous proxies cited, each showing extremely high results for warming in the supposedly ‘murky’ MWP. The only arguments in defense offered by the panel was that the MWP did not seem to be spatially or temporally coherent across the globe, and from the statistician Bloomfield, that it is OK for uncertainty to increase with additional information. The reporter noted that with the millions of dollars being spent on climate change that a report should come out saying that confidence in temperatures during that period is decreasing, not increasing, is a somewhat unsatisfactory outcome.
The size and extent of warming is crucial to biodiversity as it is an measure of extent of variation that present biodiversity has been exposed to and survived.
Models like the hockey stick graph have an appearance of clarity, but are really like Simulacra with an hallucinatory resemblance to the real. This is dangerous. Under scrutiny only the obvious and uncontested parts survive (the warming of the last 400 years) and the important part, past temperatures relative to the present day, become ‘murky’.
How do we deal with a world where reality is indistinguishable from illusion? We perform experiments.
- stage 1: attempt to replicate the result exactly, to see if this at least stable.
- stage 2: think of a test that tells us if it is real.
- stage 3: carry out that test.
The test are showing extremely high results for warming in the supposedly ‘murky’ MWP. One of the many flow-ons of this may be the sensitivity to variations in solar intensity in models must be reparametrized. Another flow-on is greater tolerance of biodiversity to climatic variation than is currently believed.
As with every Frankenstein story, however, the MBH98 Simulacrum experience takes on a life of its own and things donâ€™t turn out exactly as planned. Control can only go so far before it devolves into chaos. To quote a line in “The Intelligent Design of Jenny Chow”:
After a major setback, Jenny Chow intones â€œIâ€™m confusedâ€; Jennifer retorts, “That’s because I made you. And you’re only going to get more confused.”
Sounds like climate history is going to get a bit more confusing too.