An interesting juxtaposition in a recent Australian. My eye was first caught by an article about a paper, lead-authored by Professor Will Steffen, predicting that beyond 2C of global warming all hell will break loose. Fortunately there was also an eminently readable piece by Professor Ian Plimer arguing the case for the beneficial effect of CO2 and demolishing the notion that it could lead to Steffen-like outcomes.
The apocalyptic ‘hothouse earth’ alarmism postulated by Steffen et al was quite common about ten years ago but has been somewhat muted of late as a consequence of the planet’s refusal to behave as catastropharians insisted it would: CO2 has risen but the global temperature, even with BoM-style gingering of temperature records, has not risen to any significant degree if at all. I wonder if President Trump’s withdrawal from the Paris Agreement might have anything to do with the re-emergence of this kind of junk ‘science’? As the US was the primary source of all those climate dollars and they have dried up, the panic amongst climate careerists is very nearly palpable. Expect to see many more of Big Climate’s rent-seekers and grant-snafflers stepping up the hysteria.
Steffen’s theory is that, once we get to 2C warming above pre-industrial levels – now only 1.2C away, as it happens –there will be “a cascade of feedbacks with terrible consequences for ecosystems, society and economies”. Without action, we are told, “the feedbacks could lead to a much higher global average temperature than any interglacial in the past 1.2 million years.”
The theory used to be that increasing atmospheric CO2 would drive increasing atmospheric temperature, which would, in turn, lead to more floods, droughts, cyclones and extinction of species. Whilst increasing CO2 is regarded as the initial trigger, the real damage, warming-wise, will be done as other factors come into play — methane released by a melting arctic tundra, for example. This is the “feedback” that has climate scientists so preoccupied it is a wonder they can marshal the concentration to lodge their latest grant applications. Well, perhaps not.
In any case, the IPCC has a metric to gauge all this “climate sensitivity”. There are two main versions – Equilibrium Climate Sensitivity (ECS) and Transient Climate Sensitivity. They are defined as follows:
The equilibrium climate sensitivity quantifies the response of the climate system to constant radiative forcing on multi-century time scales. It is defined as the change in global mean surface temperature at equilibrium that is caused by a doubling of the atmospheric CO2 concentration.
The transient climate response quantifies the response of the climate system to an increasing radiative forcing on a decadal to century timescale. It is defined as the change in global mean surface temperature at the time when the atmospheric CO2 concentration has doubled in a scenario of concentration increasing at 1% per year.
Since ECS quantifies the end-game, and is a simpler concept to understand, I will concentrateon that metric, of which there are three important things to note.
The first is that ECS can only have one value: the temperature rise associated with a doubling of atmospheric CO2. But we don’t know what that figure is. The IPCC believes it is somewhere between 1.5C and 4.5C, and it has held to that range for the entire 30-plus year history of so-called climate “science”. In other words, our understanding of this fundamental metric has not advanced one iota in that time. So much for ‘settled science’.
The second is that it includes the feedback (or amplification) due to increased water vapour and other greenhouse gases.
And the third important point is that it is a logarithmic function. In layman’s terms that means the effect diminishes the longer it endures. Okay, let’s say we start with an atmospheric CO2 concentration of 280ppm (pre-industrial) and let’s further say, for argument’s sake, that the value for ECS is 2C. Therefore by the time we get to 560ppm (we are currently at about 410ppm, roughly halfway there) we should see a temperature increase of 2C. But, according to the theory behind ECS, to get to 4C, we would then need to add another 560ppm to give us a total concentration of 1120ppm. This effect is best illustrated with a graph:
Don’t worry about the scale. This is not the graph for ECS but a generic logarithmic curve. If we assign CO2 concentration to the x-axis and temperature increase to the y-axis, we can clearly see that most of the warming occurs in the early stages. In theory, we should already have experienced much more than half of the warming attributable to the initial doubling of CO2 from 280ppm to 560ppm. In the real world, not the one inhabited by climate careerists and the amiable reporters who take their every dire word as gospel, we’ve seen 0.7C of warming some, possibly most, of which would be attributable to natural factors. There are many papers by credible scientists that postulate ECS values hovering around the 1C (or even lower) mark.
I should point out that the IPCC believes the calculated temperature rise from any particular increase in CO2, called the committed temperature, is always higher than the realised temperature at any point in time. Translate this as meaning there is a time lag before full warming is achieved. They further tell us that if the ECS is 1.5C then realised temperature is 80% of committed temperature. If it’s 4.5C – their highest estimate – the factor is 50%. So I don’t think this wrinkle affects my point too much, which, to reiterate, is that we’ve already seen most of the warming attributable to doubling CO2 concentration from 280ppm to 560ppm and it doesn’t look that scary.
If climate sensitivity is the driving mechanism of CAGW, It is difficult to see how runaway warming can occur in the absence of a whole raft of new feedbacks. And that is what Steffen et al have given us in spades to account for their “much higher global average temperature than any interglacial in the past 1.2 million year”. They include:
permafrost thaw, loss of methane hydrates from the ocean floor, weakening land and ocean carbon sinks, increasing bacterial respiration in the oceans, Amazon rainforest dieback, boreal forest dieback, reduction of northern hemisphere snow cover, loss of Arctic summer sea ice, and reduction of Antarctic sea ice and polar ice sheets.
Here let us pause to consider one of those remarkable coincidences. Whenever wild weather makes the news anywhere in the world, climate porn soon follows. Just lately there have been heatwaves in Europe, plus wildfires in the US and drought right here at home. With the predictable certainty of night following day, Big Climate’s urgers are out and about and proclaiming that the end is even more nigh than it was the last time.
Now we have Steffen telling us that even if we did achieve that 2C target we’d still be on the knife’s edge of cataclysmic upheaval.
Apparently, even if the alleged warming can be made to stop at the long-vaunted 2C, climate scientists will see no decrease in job security. Nice work if you can whip it up for yourself.
So let’s take Big Climate at its word. Were you a prime minister cut from the normal political cloth, rather than the sterner Trumpian stuff, you would by now be grasping the monumental con job Big Climate has perpetrated. You would need, therefore, to gently nudge voters away from the views decades of hucksterism and propaganda have inculcated. What would you say? Perhaps you could take this tack:
“We were assured that a 2C ceiling would keep the planet safe, but Professor Steffen and others now tell us that will not be enough. So let us be logical and examine what value for money we are getting from wind farms and solar projects, which we know are both unreliable and forcing our electricity bills through the roof. Does it make sense to persist? Men and women of Australia, I tell you it does not.
“If the climateers are indeed correct and temperatures are on a one-way ascent, wouldn’t it be more sensible to prepare for those hot days?
“So here is what I propose: no more of your tax dollars for rent-seeking gougers like AGL. Not another cent to the Clean Energy Finance Corporation. No more grants to the universities’ climate departments.
“Instead, we’ll put that money into restoring the reliability of our power grid because, according to the good Professor Steffen and so many others, things are going to get so hot we’ll need reliable air conditioning.”
Yes, a prime minister who said as much would be most welcome.
Instead we have Malcolm Turnbull. Sad, isn’t it?