Nicco
thanks for the references. Just so you know, citing a Michael Mann paper is akin to me quoting an Australian Coal Industry study to you as "proof" of whatever. But in any case the paper seems to be just kicking around the dates of the MWP and Little Ice Age - lots of papers on that point - and does not have anything much to do with glaciers as such.

The second reference is about a subset of glaciers in North America not behaving as they should - that is, actually growing - during the MWP, although I was under the impression conditions were different for centuries in parts of America.

But in any case we are still well short of any average of behaviour and still have only the one reference to glaciers and the MWP, so your arguement, and your original criticism of me, completely fails. But enough of this. Leave it with you.

Given that there is no compelling scientific evidence that anthropogenic CO2 emissions are the driver of climate change, it was surprising to hear Ross Garnaut brazenly claim that AGW has now been proved beyond reasonable doubt. As Tom Quirk demonstrates, Garnaut's rationale has been shown to be simplistic and invalid. Thus, Garnaut's economic recommendations on climate change policy, need to be qualified as being irrational, as they are based on the erroneous assumption that the AGW science is settled.

Similarly, the Productivity Commission's (PC's) conclusions about the relative efficiency of carbon taxes and emission trading schemes made in its report, 'Carbon Emission Policies in Key Economies', need to be qualified. As its terms of reference did not include reviewing the veracity of AGW 'science' , the PC was forced to assume that climate science is settled, and that there is a need to reduce carbon dioxide (CO2) concentrations in the atmosphere. Consequently, its carbon tax/ETS conclusions are hypothetical, and cannot be regarded as justification for the Government's proposed carbon tax policy which lacks scientific and economic justification. The PC found that the renewable energy incentive policies that have been implemented by governments both here and overseas , are very high cost and their continuation unjustified.

The Government is being deceptive in claiming that Treasury modelling shows that the carbon tax would have minimal impact on the economy. As economist Warwick McKibbin pointed out on ABC Lateline Business, there is a serious shortcoming in the Treasury modelling, as it is based on the erroneous assumption that employment would not be affected by imposition of a carbon tax. In other words, the modelling is too simplistic to have any credibility.

Tom Quirk is asking us to believe a load of nonsense – and he knows it. He knows that an oscillation such as the Pacific Decadal Oscillation is not a forcing mechanism. It does not add to the amount of energy in the atmosphere or ocean but merely transfers energy between them.

This is evident from the fact that fitting a line to the century of PDO data which is available does not produce a trend. On the other hand, fitting a line to average global temperature records for the same period does produce a clear and statistically significant upward trend, which is ongoing. Why? Because average global temperature is rising.

He also knows that the red line drawn between carefully selected points to show decline or flat-line temperature movement is equally a nonsense. Take for example the red line shown on Fig 2 of the article, purporting to show a decline in temperature over the period 1947-1975.

Even a cursory inspection makes it clear that this “decline” is false, since most of the recorded temperature points are well above the red-line, making it impossible for the line to show a decline.

By relating chalk and cheese one can, presumably, prove anything to be true!

Mark Curmudgeon repeatedly claims to have examined the science of climate change, and the science of declining glaciers, and the science of sea level rise, and so on. He also lays claim to having been a science reporter (and by implication, having some background in science).

In his most recent offering, he is disparaging about Professor Michael Mann, suggesting that Mann's scientific papers are in some way unreliable.

This gives the game away. Mann is a regular target, and his work is routinely disparaged - but not by scientists. He is attacked and indeed vilified by political and economic critics, for reasons which have little to do with science.

Among the climate science community he is regarded as one of the major players, whose work has developed and evolved over the past decades, and whose (strong) opinions are always worth considering. He has received awards from Science, Nature, the Association of American Geographers, the American Geophysical Union, and many more, while also having the support of the US National Academy of Sciences.

Curmudgeon's sneer at Professor Mann shows (once again) that science takes second place to ideology in Curmudgeon's cosmos.

Those interested in the validity or non-validity of the science behind CAGW will find much of interest at the Climate Etc blog (http://judithcurry.com/). As an economist, my take here is that Garnaut, once a first-rate economist who did some good work, has been seduced by the fame and kudos (in some quarters) of being a highly-partisan point man for the ALP on its most prominent, government-defining, issue, and that his analytical rigour in assessing "climate change" "science" is much less than he once applied in his area of expertise.

If it comes to a choice between Garnaut and Warwick McKibbin, I (and I think the great majority of economists) would rank McKibbin as a superior, more rigorous, source.

As for the article, it seems to raise points in areas which have never been adequately addressed in warmist models.