SSP5-8.5: Garbage In, Doomcasting Out

SSP5-8.5: Garbage In, Doomcasting Out

By Willis Eschenbach

You might have read about RCP8.5, which is now called SSP5-8.5. It is the most extreme future scenario proposed by the IPCC. You might also have read that it is being thrown in the trash can.

Finally, you may have seen claims from the usual suspects that the death of SSP5-8.5 is because we’ve been so gosh-darned successful in reducing CO2 emissions. Gavin Schmidt’s RealClimate blog (where I’ve been banned for a couple of decades now) mentions the effects of “the Montreal Protocol, the Clean Air Acts, renewable energy price falls, fracking, the Paris Agreement, actual climate policies”.

Figure 1. The inexorable rise of atmospheric CO2. If emissions were dropping as the usual suspects claim, the rise would be slowing.

But some imagined drop in emissions is not the reason that SSP5-8.5 was killed. That hasn’t happened. Here’s a detailed look at the changes in the trajectory of the atmospheric CO2.

Figure 2. Actual atmospheric CO2 concentration, and the calculated acceleration of the concentration.

There’s been no change in the progression of atmospheric CO2. SSP5-85 died because it was alarmist nonsense from Day One, and the IPCC is finally admitting that obvious fact.

SSP5-8.5 is an economic fairy tale commissioned around 2011 for the IPCC, stitched together by a crew of modelers told to imagine how to drive CO₂ emissions into the stratosphere by 2100. The task was not “what’s likely?”, but “what would it take to get the highest plausible emissions you can mathematically torture out of the system?”

To get there, they had to run history backwards. Instead of continuing the observed move away from coal toward oil, gas, and non-fossil energy, they assumed a huge global lurch back to coal, with coal use multiplying several-fold so that by the end of the century, roughly half of all energy on Earth comes from coal alone. Not just for electricity either—coal-to-liquids for cars and planes, as though the world looked at cheaper, cleaner competition and said: “No thanks, bring me more soot.”

Even that wasn’t enough. So population growth, which in the real world has been slowing, gets dialed up to around 11–12 billion people by 2100, right out near the high end of speculative projections.

That still wasn’t enough. So technological progress in energy efficiency, which has been marching along for decades, is assumed to more or less stall, so we keep wasting energy like there’s no tomorrow.

And on top of that, the scenario simply supposes that meaningful climate policy never really bites anywhere that matters—no sustained global effort to bend the emissions curve for the rest of the century.

String all of that together, and you get SSP5-85: a “fossil-fueled development” storyline where coal dominates, population balloons, innovation sputters, and policy sleeps.

It may or may not have been useful as a stress test of the climate system under extreme forcing. But as a picture of where the real world is actually headed, it depended on a long list of things all going wrong, all at once, for a very long time—which is precisely why the common practice of treating it as “business as usual” was alarmist storytelling, not science.

And telling these stories has caused real damage. SSP5-8.5 has been the backbone for all the exaggerated claims of sea level rise, extreme weather, and upcoming Thermageddon™. It has been put forward as the main argument for the insane “Net Zero” policies bankrupting the nations foolish enough to sign on to them. It has caused no end of trouble.

So don’t believe the merchants of doom and the serial failed doomcasters. SSP5-8.5 was garbage from the start, and that’s why it was thrown out. Nothing to do with fancied changes in emissions, and everything to do with the fact that it was designed as a propaganda tool.

However, don’t think we can rest on our laurels. The usual suspects will just latch onto the next most alarmist scenario, SSP3-7.0, which is only slightly better … you see, the problem is that the mainstream climate scientists are caught in the Sinclair Trap, viz:

“It is difficult to get a man to understand something when his salary depends upon his not understanding it.”

My best to all on a foggy night here in the forest on a hill,

w.

Oh, yeah: When you comment, please do everyone a favor and QUOTE THE EXACT WORDS YOU ARE DISCUSSING. I can defend my own words. I can’t defend your restatement of my ideas.

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