Science with the Substance of Mere Vapour

Are you feeling the cold where you live?  Hoping for a spot of global warming?  Well, you’re not alone.  Where I live in Kiama, I reckon we are experiencing the coldest winter in donkey’s years (excuse the scientific terminology) and just now, as I write it, it is 11C at 9.0am, plus a bitter wind.

CAGW alarmists cover this apparent failure of their theory by telling you that global warming initially manifests itself by disrupting normal climate and this will involve all sorts of extremes.  But they can’t avoid the fact that, in the end, the world must get noticeably hotter.  By which I mean noticeably hotter over a significant length of time across the entire globe.  By which I mean new heat records vastly outnumber new cold records. That new cold records disappear (and not just down the memory hole).  How long will that take?

You, like me, might be thinking that it should have kicked in by now.   What prompted me to delve once again into this subject was a story on the ABC a few weeks ago that reported Paris Games organisers were worried that climate change might make the Games dangerously hot for athletes.  So, I thought I would check just how extreme the heat has become. It is now claimed 2023 to be the hottest on record, but before that 2016 held that dubious record.  It was recorded, by NOAA, as 0.94C above the 20^th century average.  NOAA has 2024 at 1.27C above the 20^th century average. So, between now and then the temperature has risen by an earth shattering 0.33C.   And, as luck would have it, 2016 saw the Olympic Games in Rio.  I don’t recall there being major heat stress problems at that Games, where you would expect the temperature to be somewhat higher than in Paris.  0.33C is not even the difference between donning a singlet or leaving it off.  I think our athletes are pretty safe.

NASA has an answer to this lack of ‘hotness’ (for want of a better word) that is puzzling you and me

But I digress.  NASA has an answer to this lack of ‘hotness’ (for want of a better word) that is puzzling you and me (https://earthobservatory.nasa.gov/world-of-change/global-temperatures):

Why should we care about one or two degrees of global warming? After all, temperatures fluctuate by many degrees every day where we live.

The temperatures we experience locally and in short periods can fluctuate significantly due to predictable, cyclical events (night and day, summer and winter) and hard-to-predict wind and precipitation patterns. But the global temperature mainly depends on how much energy the planet receives from the Sun and how much it radiates back into space. The energy coming from the Sun fluctuates very little by year, while the amount of energy radiated by Earth is closely tied to the chemical composition of the atmosphere—particularly the amount of heat-trapping greenhouse gases.

Got that?  Any significant change in temperature must be caused by changes in the atmosphere. The unspoken premise being that only human action can change the atmosphere.  Now read on:

A one-degree global change is significant because it takes a vast amount of heat to warm all of the oceans, the atmosphere, and the land masses by that much. In the past, a one- to two-degree drop was all it took to plunge the Earth into the Little Ice Age. A five-degree drop was enough to bury a large part of North America under a towering mass of ice 20,000 years ago.

So, what atmospheric changes caused those 1-2C and 5C drops?  And what atmospheric changes caused them to be reversed? This NASA article doesn’t feel the need to explain because that might reveal that there are forcings that affect global temperatures other than us pesky humans.  What an own goal!  Best not to say the unspoken bit out loud, NASA.

I started following the CAGW debate seriously over 15 years ago.  I very soon came to the conclusion that CAGW is a very dubious concept.  Over the years my conviction has firmed to the point where I now recognise a monstrous scam.

The basic science is that CO2 and other gases (including water) trap certain frequencies of reflected (outgoing) infra-red radiation in the atmosphere, rather than allowing them to escape into space. As far as CO2 is concerned, those frequencies are 15-, 5- and 4.3-microns.  This bandwidth comprises about 10 per cent of outgoing radiation.

This means that, at some point, the CO2 concentration will have absorbed all the radiation in these bandwidths and adding further CO2 will have no warming effect.  The theory of CAGW has its scientific basis in a concept called Climate Sensitivity, which is defined as the temperature increase that will result from a doubling of atmospheric CO2.  This is a logarithmic function.  Each 1C temperature rise will require double the amount of CO2 that caused the previous 1C rise.  Put another way, this is subject to the law of diminishing returns.

Climate ‘scientists’ do not know what the value of Climate Sensitivity is.

Climate ‘scientists’ do not know what the value of Climate Sensitivity is.  They estimate it is somewhere between 1C and 2.5C, in terms of short term (called transient) effect and 2.5C to 4C for long term (called equilibrium) effect.

I have no idea what the equilibrium result might be, but we have enough data now to have pretty good guess at the transient response.   The claim is that the human induced temperature rise over the past century is approx 1C.  And we know that atmospheric CO2 concentration has risen from 280ppm to 427ppm over that period.  That is about a 75 per cent increase. So, it is a reasonable assumption that a further 25 per centy increase will add no more than another 0.3C to the temperature.   And on this basis, having got there, we would need to add a further 1120ppm of CO2 to the atmosphere to get to 2.6C of warming. How long will that take I wonder?  Until the twelfth of never?  Certainly, long enough to allow us in Australia, and everywhere else for that matter, to, for example, deploy nuclear power.  If, in fact, it were actually necessary, but I think that’s a battle already lost.

Given that Climate Sensitivity is central to the theory of global warming, you would expect it to be front and centre in the IPPC’s 6^th (and latest) Assessment Report, as it was in previous Reports.  But I have checked in vain for any mention of Climate Sensitivity in either the short (42 page) Summary for Policymakers or the long (81page) version.

As I sit here shivering in Kiama, I wonder why that is?  Could it be because they, and their activist cheer squad, are telling us that we have only few years in which to cut emissions to zero in order to avoid catastrophic warming of 2C.  That claim flies in the face of what the theory of climate sensitivity tells us, as I have outlined above.  Namely, that even if you accept the CAGW scare, we have plenty of time to act.  No need for Australia to lead the rest of the world over an energy cliff.  It seems to me that, from their point of view, the less said about the scientific foundation of CAGW, the better.