Q&A,

I am pleased you have devoted so much effort in responding to JohnH and other "skeptics" in such measured terms and with obviously cogent arguments.

While it might feel to you like beating your head against a brick wall since the skeptics refuse to be swayed, I believe it is still a worthwhile exercise on your part as there are doubtless many other more open minded people reading your posts. Many of these will surely end up discounting the fatuous arguments of the skeptics.

Chappo.

Your argument astounds me.

You state: “such cautious, carefully modelled projections based on AGW theory are ‘crystal-ball gazing’ is insulting to *all* scientists, as it discredits the fundamental scientific approach of putting forward hypotheses and testing them against the evidence”.

Perhaps you should analyse carefully what you have said – because I am not aware of any evidence for AGW that has been tested, giving an irrefutable outcome, which, by definition, is needed to validate the AGW hypothesis. If the evidence cannot be furnished, then the fundamental scientific approach is invalid.

You say: “The case for AGW will never be proven (any more than you can ‘prove’ the existence of gravity) but there is evidence to support it”. Please, what is that evidence? Moreover, with gravity, cause and effect have long been “proven”, because the proof is in personal experience and observation, but where has cause and effect been reliably and conclusively observed with AGW? If you say there is correlation between Keeling Curve and average global temperature, I suggest you check out solar activity (sun spots) versus temperature, because the correlation is considerably better.

Yes, “Newton’s theory of gravity warrants respect”, but not so the pseudo-science of AGW.

There are around 23 “crystal-ball” GCMs, no doubt all cautiously and carefully modelled, but no two produce the same result – so which “correct” ones did the IPCC experts select for their careful projections? The data input to the GCMs are incomplete, and that’s by IPCC’s own admission.

Earth’s climate is complex, with its elements constantly interacting, and the IPCC obviously hasn’t yet come to grips with its complexities, hence the need for the GCMs to be constantly tweaked.

I’m sure you are aware that average global temperatures have cooled over at least the past five years and especially over the last two, but initially the IPCC projected that temperatures would steadily rise – how do you explain that? I put it to you that IPCC’s projections are no different to mathematical extrapolations – unpredictable or unreliable.

I don’t dispute your penultimate paragraph, but your last paragraph is risible.

Kulu

I appreciate your thoughts. The people that count are aware and they are not close-minded.

If you follow JohnH’s argument to its conclusion, the only way to test the original hypothesis of AGW is to conduct the experiment. That is not rational, nor is it logical – for obvious reasons.

There is a plethora of metrics that can test the hypothesis - a particular analysis, when it supports another’s conclusion, adds robustness to it. JohnH does not appear to understand or appreciate this; whether it be tree rings, corals, ice cores, stalactites/mites, boreholes, etc or the various GCMs - regardless other indicators.

Over time, when there is a preponderance of conclusions from different sources (showing similar trends for the palaeoclimate temperature record, for example) then the initial hypothesis becomes theory.

Direct evidence in support of a theory can take a long time to present itself, and is often determinant on the technology/s available at the time. However, this in itself is not a sufficient condition to reject the theory, as JohnH is wont to do wrt AGW. Evidence of Einstein’s special theory of relativity and the equivalence of mass and energy is a case in point.

Even a 'wanabe' atmospheric physicist like a retired Novocastrian metallurgist would have difficulty ‘explaining away’ tropospheric warming together with stratospheric cooling.

JohnH

Snide and snarky remarks that the IPCC indulge in crystal-ball gazing just demonstrates to me you have no intention of engaging in reasoned or rational discourse, with me or anyone else, about climate change.

Time series analysis (in general) utilising time series filters (in particular) are excellent tools to help real scientists analyse trends. They are far from infallible (as alluded to in my response to kulu), however, they are most definitely not an example of a “crystal ball” as you allude to in your polemic to me, Chappo and others. They are infinitely better than any “analysis” I’ve seen come from any of your comments.

You combine outright denial of real trends, in whichever metric, which are abundantly clear and undeniably statistically significant, with stubborn refusal to accept what the numerous proxy-reconstruction temperature data sets show prior to the satellite era.

You’ve also repudiated GCMs without clearly understanding what the GCMs are or what they model; or how, where and why they do what they do. I intimated in a previous comment that you (notwithstanding your stated time honoured expertise in metallurgy) just want to dismiss any scientific support (past, present or future) for AGW out of hand.

Your response to me and others does not alter my perception that you are just an anti-AGW sophist and don’t know what you are talking about, but that is only my opinion.

I agree about your views on CCS, I’ll leave it at that.

The claim that human activities have played a significant role in changing global climate trends is obviously not one that can be proved beyond any doubt at all as there are so many variables, known and possibly unknown, controllable (GHG, clearing etc) and uncontrollable (sun spots, earth's orbit etc) that are involved in what causes our climate to behave as it does.

On top of this there are problems with establishing accurate data particularly from the past. There are also difficulties and some legitimate controversies involved in measuring some of the variable causes and effects of climate change - Newton was lucky he only had to explain gravity, not piece together the dozens of interrelating variables that effect climate.

In spite of these difficulties there are some provable facts that to my simple mind explain why global warming is much more likely than not to result from human activities.

It is a fact, is it not, that the burning of fossil fuels, and the clearing of tropical forests emit sequestrated CO2 and other GHG's into the atmosphere?

It is a fact, is it not, that CO2 and the other GHG's allow light from the sun to pass but absorb reflected heat from the earth?

If these are facts; and notwithstanding possible negative feedbacks that may mitigate the warming effects of increased GHG's then everything points towards an ever warmer climate in the future.

JohnH, I ask, are you saying:-

that the scientists have got it so wrong that global warming is unlikely to result from our activities,

or climate change may result from our activities but we need not be sufficiently concerned about it to warrant any meaningful action (ie the risks of doing something outweigh those of doing nothing, or, if it does happen others can deal with it)

Q&A

Really, your sinking to personal attack and invective does not surprise me, because this seems to be a trait among the warming fraternity when their bullying gets them nowhere. Quite often though, the sceptic is alleged to be in the pay of the fossil fuel industry. I notice, for instance, that Dr Michael Mann only a few days ago vehemently attacked one of his critics (Lawrence Solomon), claiming he received fossil fuel funding; this attack was in relation to Mann et al’s paper in Nature, purporting that the Antarctic is warming. Solomon’s criticism followed Mann’s admission that he had “carefully interpolated” temperature data – put crudely, he guessed the necessary values.

I would have thought that readers of these posts would have realised that my use of “crystal-ball gazing” was metaphorical. Perhaps my judgement was misplaced. The point I was making, of course, is that climate is so complex, with a huge number of interacting factors (some unknown) that it is impossible to foretell what the future holds.

We have been regaled over time with dire warnings that the polar regions would melt and that average global temperatures would progressively rise. But what has happened? Current sea ice and temperatures are at 1979 levels. We have been told that sea levels would rise dramatically – no they haven’t.

Re hockey sticks, may I suggest you read “The winter of incomparable cold” in New Scientist, 7.2.09, and then compare its data with those in AR4, Figure 6.10 (b). Strangely, the hockey sticks seem to have missed these important climatic events.

“Direct evidence in support of a theory [hypothesis!] can take a long time to present itself”. Climate scientists have been striving to find direct evidence since the 1970s (e.g. see National Geographic Nov. 1976 “What’s happening to our climate”, pp.576-615). How much longer will it take? Because, 40 years on, the science is still far from settled and just about all of the so-called evidence is controversial. In the meantime, governments around the world are being held to ransom and many are in turmoil over what to do.