AGW – How can this multi-dimensional, multi-parameter, multi-variate climate science be settled?

Hopefully I am not infringing ethics or copyrights here. In reading WUWT‘s post ‘Back-testing the Solar-Sea level Relationship’, there is an incredible amount of data and discussion on this climate ‘debate’.

Anyone who claims that the science is settled, as the ‘warmist’ scientists and their followers and supporters do, in fact claim, cannot reasonably be judged to be competent scientists or logical thinkers. There are simply too many variables, hardly any of them being scientifically quantifiable with any acceptable degree of certainty, to be assessed with any degree of confidence. Certainly insufficient real confidence to base the world-shattering carbon control and trading schemes being implemented by the authorities.

Critics of “skeptics” say that ‘we’ keep changing from one aspect to another, according to them to avoid the criticisms. In reality we are simply demonstrating that there are so many aspects the ‘warmists’ are simply ignoring, in their blinkered view of ‘CO2 causes global warming – we must control the emissions’.

In addition to the above-referenced post, I would venture to copy one of the reader comments from that post, as further support for the claim that “the science is not settled”.

rgbatduke says:

As Solanki noted in 2004, the Sun was more active in the second half of the 20th Century than at any time in the previous 8,000 years That was very likely not the case at all:

Your case for some fraction of the SSN increase being the result of alterations in the methods of counting is fairly compelling, although I would still worry about the error bars on your proposed corrections (and some of the inconsistencies that you acknowledge).  However, all of these corrections apply at most to the sunspot record, and really only to a relatively short century timescale of the sunspot record — over a longer timescale the sunspot records span multiple humans, methods, tools and are difficult to compare to contemporary records on a quantitative basis, are they not?

I’m curious, though, how you extend the conclusion that the 20th century was exceptional in solar activity back over the entire Holocene.  Isn’t most of that conclusion derived from completely independent proxies, in particular radioactive proxies?  Again, there is a lot of literature and having started to read my way through a lot of the older literature (and observing your name repeatedly as a cited reference:-) I’m certain that you are far more familiar with this literature than I, but the review by Ushokin (2008) has some radioactive proxy derived figures that — if they are reliable, which I am not equipped to judge — fairly unambiguously suggest that the 20th century was indeed exceptional over the Holocene.  See e.g. Figure 14 or Figure 17.  Is this junk science?  If so, how do we know — what is wrong with the reconstructions?

In any event, it is not clear what relevance a correction to the smoothed sunspot number in the 20th century has to the radioactive proxy record on a millennial scale.   Of course the 20th century itself is a serious problem in many ways.  As noted in the article, a variety of factors from extensive nuclear testing in the late 50s through early 70s (much of it atmospheric) to the release of C_14 depleted carbon into the atmospheric cycle from the burning of aged-out fossil fuels (Suess effect) which is itself confounded by the further release of aged out CO_2 from oceanic stores by global warming.  The Be record in that sense seems to be somewhat less easily confounded, but even there we don’t necessarily know what is going on.

Looking at Ushokin and your talk, I remain unconvinced that the level of solar activity in the late 20th century was not unusual over a millennial time scale, although you have certainly cast some doubt on the issue.   If nothing else, we live in “interesting times” (possibly in the sense of the Chinese curse).  Whether or not the late 20th century was a millennial-scale peak in solar activity in terms of any or all measures of solar activity (where SSN is just one, and as I think you note, not really the best one to use as a proxy in part because it is subject to a fair bit of quantitative or subjective interpretation and hence variation), solar activity is now far down from whatever kind of peak that it was, and promises to go down further still.  We are thus at a critical point in theories that attempt to connect solar activity to global climate in contrast to CO_2.  If global temperatures hold or decrease in the teeth of inexorably increasing CO_2, it will at the very least be yet another compelling coincidence between secular climate changes and secular changes in solar activity by any or all measures.

We need not be too concerned that such coincidences fail, in and of themselves, to be strongly predictive in either forecast or hindcast, because anybody who thinks that global climate can be explained by simple/logistic one-parameter models is so obviously mistaken that they shouldn’t at this point be taken seriously in the debate.  Climate variation is clearly multivariate in its functional form, with non-Markovian effects from a broad range of time scales.  So it is entirely plausible that climate is driven directly and indirectly by solar state but that the effect is only strong when other modulators are in the right state or phase (e.g. the decadal oscillations, oceanic state, whatever).

Climate is a hard problem.  I was reading the Google Books copy of Solar Variability, Weather and Climate (1982) and was struck by the fact that — 30 years after this review was written — almost nothing has changed.  Well, one thing has changed — the book as far as I can tell mentions “CO_2″ no more than two times in all of its pages as a possibly significant driver of global climate.  But in particular, all of the open questions it cites are still open questions.  There are compelling coincidences between solar state and climate, but few of them stand up over very long time scales and all of them are difficult to explain because the problem is multivariate with many negative feedbacks!

There was a lovely paragraph in one of the articles where it was pointed out that in many winters, a heavy snowfall can blanket a geologically signficant fraction of e.g. North America, greatly increasing its albedo.  Yet, instead of reflecting enough heat to trigger a return to ice age conditions, negative feedbacks almost instantly kick in, the snow melts, and things return to “normal”.  For better or worse, physics addresses the time scale of right now — the sun kicks out a CME and it affects things now (where “now” is on a timescale of hours, days).  Snow falls.  Hurricanes loom.  Magnetic fields shift.  Solar constant varies.  Albedo bounces up and down as clouds form an ice forms or melts.  All of the feedbacks tend to minimize these influences — they change things for a day, a week, but after a month or more the climate system has “forgotten” them due to damping.

Or has it?  Somehow there is long time scale modulation that influences climate, where tiny changes in some driver(s) in the multivariate system shifts the climate trajectory around.   Simple descriptions fail because the changes are nonlinear and coupled; it isn’t “this”, it is “this, and this, and that, and the other thing too”, and not just now but ten years ago, twenty years ago, fifty or five hundred years ago that contribute.

I continue to be baffled by the really long time scale variability in the Earth’s climate.  Is the current ice age (the one that started 3 million years ago) caused by real solar variability, the helium burning cycle that can drop solar output “suddenly” (by geological time standards) and then only slowly build it up again?   What causes the bistability between regression to warm phase behavior from the newly dominant cold phase?  (Not what MODULATES this bistability, what is its CAUSE.)

Many questions, few answers, and even modern physics aided with satellites and advanced instrumentation cannot overcome the curse of short baselines of truly accurate observations, decades to predict centuries and millennia and million year variations.



About Ken McMurtrie

Retired Electronics Engineer, most recently installing and maintaining medical X-Ray equipment. A mature age "student" of Life and Nature, an advocate of Truth, Justice and Humanity, promoting awareness of the injustices in the world.
This entry was posted in AGW, carbon tax, climate change, ENVIRONMENT, Human Behaviour, World Issues and tagged , , , , , , , , , , , . Bookmark the permalink.

2 Responses to AGW – How can this multi-dimensional, multi-parameter, multi-variate climate science be settled?

  1. Pingback: The Highest Authority in Science is the Data | The GOLDEN RULE

  2. Pingback: AGW – Climate Change – Unsettled Science | The GOLDEN RULE

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