Readers may remember a CAGW paper, co-authored by Professor David Karoly, that professed to demonstrate recent climate extremes in south-east Australia were unprecedented in the paleoclimate record. This paper was announced with suitably hysterical headlines as you might expect. Then sceptic Steve McIntyre identified a fatal flaw within hours of publication and it was withdrawn for “revision”. This took all of four years to publish and, when resubmitted, produced markedly less alarming conclusions. To no-one’s surprise this farce was conveniently overlooked by the mainstream media. You can read all about it here.
Anyway, the redoubtable Dr Karoly is back in the news today having co-authored a new paper which can only strike those without a seat on the warmist gravy train as plumbing the depths of desperation. They can see the writing on the wall. As CO2 concentrations inexorably rise and global temperatures disobligingly refuse to rocket upwards, the warmist establishment sees the need for a new and foolproof narrative. They have done it often enough before, so it is not as if switching stories is a great challenge. Remember those dams that would never fill again and, when they did, how the narrative switched tacks and proclaimed torrential downpours and flooding as the “genuine” consequences of electricity bills that just aren’t high enough?
The latest line appears to be that, even if CO2 doesn’t cause warming per se it can still cause “extreme weather” through some other, unspecified and malign influence. Thanks to Eric Worrall at WUWT for spotting the latest meme switch.
Now I haven’t read the paper, it being paywalled, and even if I did I’m sure it would
dazzle baffle me with ‘science’. However, I have read the abstract, which pretty much tells you all you need to know. Here is how it begins (emphasis added):
The Paris Agreement aims to ‘pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels.’ However, it has been suggested that temperature targets alone are insufficient to limit the risks associated with anthropogenic emissions
So, greenhouse gases raise temperatures, and if they don’traise temperatures there is still no need to hand back all those lovely grants and turn-left seats on jets shuttling the climate priesthood to the next international conference with full room service. This is the next stage in the terminological evolution from Catastrophic Anthropogenic Global Warming, through Climate Change, to Climate Disruption. It’s a very long way from a quite specific theory we were told was ‘the settled science’ to one that infinitely malleable. So how did professor Karoly et al formulate their latest alarum? With yet more models, of course!
Here, using an ensemble of model simulations, we show that atmospheric CO2 increase—an even more predictable consequence of emissions than global temperature increase—has a significant direct impact on Northern Hemisphere summer temperature, heat stress, and tropical precipitation extremes.
What do they want from this?
Hence in an iterative climate mitigation regime aiming solely for a specific temperature goal, an unexpectedly low climate response may have corresponding ‘dangerous’ changes in extreme events. The direct impact of higher CO2 concentrations on climate extremes therefore substantially reduces the upper bound of the carbon budget, and highlights the need to explicitly limit atmospheric CO2 concentration when formulating allowable emissions. Thus, complementing global mean temperature goals with explicit limits on atmospheric CO2 concentrations in future climate policy would limit the adverse effects of high-impact weather extremes.
This is just laughable. What they appear to be saying is that ‘we don’t seem to be able to predict warming all that well. But we can predict atmospheric CO2 concentrations pretty accurately, so let’s make them our focus rather than those temperature increases that haven’t been happening’. Don’t look behind the curtain, folks, there’s nothing to see there. Too right, there’s not.
And of course, there is a rider: Predictably it is an implicit plea to keep those grants coming.
“Future work is needed to confirm exactly why we see this direct CO2 effect, but current research points to a combination of circulation and cloud cover changes, and an increase in the amount of direct radiation on the Earth’s surface due to simply having more CO2 in the atmosphere,” said Hugh Baker, a DPhil student at Oxford University.
Ah yes, follow the money.
It is difficult for the layman to decipher the complexities of a scientific paper, particularly given the nature of statistics which underpins ‘climate research’ to a greater extent than most fields of study. As has been their norm throughout the climate scam’s endless hyperbolic iterations, we can expect politicians to accept the latest advice by supposedly objective scientific advisors. If the past is any indication, the natural scepticism that should be a character trait of all who dispense public monies will not likely be in evidence.
Sad indeed it is that, while the ever-changing tales of careerist catastropharians are accepted as gospel without benefit of empirical evidence, the beggaring of household budgets and very obvious destruction of a nation’s industrial capacity by ruinous electricity costs is never noticed.
In 2009, Professor Karoly was adamant about the direct relationship between CO2 and much higher temperatures, as he explains about 90 seconds into the above clip. Today, not so much.