Good morning, Alex (at least, it is a sunny morning as I write),
My apologies for not replying earlier; I have been busy with sundry tasks, and also am rusty on my climate knowledge, such as it is. you know, I remember standing in a very dry paddock on another hot dry day on my woolgrowing property in about 2002, wondering what the climate and its implications would be like for my grandchildren. That long drought eventually passed - I remember another farmer commenting about the vicious Federation drought that started in 1896; he wonder whether we were living though something similar. Actually, the Federation drought was far worse - weeks of very high temperatures. I find the newspaper reports of the time useful.
Thanks for the information and reference to Royer's paper; I can make more sense of the abstract than the charts. For me, the question remains, is CO2 level change the cause, or effect of temperature change? To illustrate, not to argue, I have the same question about high cholesterol levels; are they the cause of heart problems, are do they occur because the body is trying to protect weakened arteries. This question is being raised in some of the medical literature, and I find it a pertinent illustration, for the "saturated fats" movement gained traction in the same way in the 1950s, with political support.
I have several concerns about the scope and manipulation of temperature records on which analysis of current trends is based, on the analysis itself, and the discrepancies with actual observation of "global" temperatures. (I'll set aside in this post the challenge of determining a "global" temperature, when all measures must
a priori be local, be they by satellite or ground readings.)
- At a public meeting some time perhaps around 2014, I asked the head of Australia's Bureau of Meteorology (BOM) why the organisation did not analyse prior records and other sources such as newspapers, to develop a reasonable record of temperatures in Australia during the 19th Century. (The BOM relies only on post-1910 records that use the Stevenson screen - you will know this, but other readers may not.) The answer he gave was "Yes, we could do that"; I sensed a lack of enthusiasm, and have seen nothing emerge. For the old-timers paid a lot of attention to records and their accuracy, and when they are augmented by stories of the time, that information is useful. Too often the description of "unprecedented" to some weather-related event, is actually quite wrong.
- The BOM has homogenised its Australian temperature records of post-1910; this is the process of altering outliers to be consistent with temperatures recorded perhaps some hundreds of kilometres distant. I find this practice quite unscientific, and wholly unacceptable. The criticisms I have read are that in reducing some "outlier" high temperatures, the overall effect is to make those earlier times seem cooler, thus making the current temperatures appear much warmer than would otherwise be the case.
- The General Climate Models (GCMs) have consistently used a climate sensitivity value of approximately 3 degrees (as also concluded in Royer's paper). However, most of the GCMs have considerably overestimated the temperatures that we have observed, and have missed the hiatus of a little over a decade from about 1998 (during which global temperatures rose very little). I know that the argument has been mounted that the "missing heat" was absorbed by the deep oceans, and I haven't been following what our recent measures have been showing, so am interested to review them. But I do think that reasoning is a case of clutching at straws.
A related but different reason for my doubts is that sea levels have been rising steadily, around 200 mm per year, and there has been no acceleration in that rise, a rise to be expected as more ice melts as we pass through one of so many warming cycles of the last 18,000 years. No acceleration in sea level rise implies no acceleration in the rate of global warming (as "climate change" used to be known, until the temperature hiatus had a few years under its belt.)
Readers interested in the history of the last forty years of climate predictions, can look them up online readily enough. Those unfulfilled predictions, made with such certainty and eminence, can have very serious consequences. For example, the operators of Brisbane'e Wivenhoe Dam may well have been convinced by such predictions about ongoing drought that they simply did not expect the deluge that eventuated, with very serious consequences. Current policies in the West concerning mining and use of fossil fuels, are of course outstanding examples.
While I understand and accept, Alex, that your concentration is on the science, I haven't the time or sufficient expertise to discuss even a fraction of all that we could discuss. What I'm seeking to do in this post is explain something of how I have come to my conclusions. For we are confronted by so much information, all the time. I imagine I could take any scientific paper that appears to support the climate scenarios that you consider possible, and have it refuted by some other scientists. Then I have to decide which argument has the greater substance, the stronger reasons to accept.
May I suggest one area for your perusal, should you not have already done so? It is the recent work of Svensmark, on the role of cosmic rays in cloud formation, with their obvious effects on temperatures. In about 1950 I first read about sunspots and an 11 year cycle, but I can't remember whether there as any discussion in the news item about temperature effects. Anyway, I think this is perhaps a very useful area of research.
Were it to be the case that "climate sceptics" (and the ones I know all are adamant that the climate changes, and is changing all the time . . . ), are correct, that the causes of change lie far beyond the role of CO2 and other greenhouse gases, ( . . . . and are more than willing to accept a transition to low-emission technologies, cost-justified, planned, and with care and consideration for energy-deprived countries desperate to raise the living standards of their people) . . . were it to be the case that they are correct, then why is it so that very many of the intelligentsia, the media (oops, have I just offended the media?), the political leaders and now business leaders, have been pursuing the anti-fossil fuel path? For I need to have plausible reasons for their choices.
We don't need to look far in history, and even just around us, to recognise how humans fear what they do not understand, and fear what they cannot control. Religion has capitalised on this: "the gods are angry with us", 'it is a just punishment from the Almighty!" Fear leads to guilt, individual and collective. The smarter ones shift the blame. With a propensity to fear and guilt in human nature, in the absence of religion it's not so hard to substitute the deities with other pieties. Thus we have done with climate fears.
The situation is exacerbated with groupthink; the zeitgeist has been found in many forms, from clerical resistance to Darwinism, to jingoism, racial and religious stereotyping and hatred, genocide. Makes cancel culture look quite harmless - except it ain't.
Let me finish on something cheerful. The waterbirds are flourishing at Narran Lakes, near Brewarrina NSW (I was there in 1995 with my teenage daughter - so glad then to cool off in the evening with a dip in the salty springs there!) But flourishing now after three La Ninas; with 25 years behind him of studying birds, a gentleman from Murray Wildlife conservation consultancy is quoted: "Most stories about the environment are pretty negative and here is mother nature controlling everything, as she does, and just renewing these populations". (
The Australian, April 8-9, 2023, page 9.)
(20min delay)