From Dr. Roy Spencer’s Global Warming Blog
Roy W. Spencer, Ph. D.
One of the main complaints rational people have had about global warming projections is that the “baseline” scenarios assumed for future CO2 emissions are well above what is realistic. As Roger Pielke, Jr, has been pointing out for years, the U.N. IPCC continues to make these exaggerated scenarios a high priority, and it looks like the next IPCC Assessment Report (AR7) will continue that tradition.
While Roger doesn’t believe there are nefarious motives in this strategy, I do: The IPCC knows very well that as long as climate models are run that produce extreme amounts of climate change, few people will question the assumptions that went into those model projections. Peoples’ careers now depend upon the continuing fear of a “climate crisis” (which has yet to materialize).
But I haven’t been able to find a good, recent graph showing how actual global CO2 emissions compare to those scenarios. So I made one. In the following plot I show estimates of global CO2 emissions from fossil fuel use through 2023, and EIA projections every 5 years from 2025 through 2050 (green). Also shown are the latest (AR6) SSP scenarios that come closest to the AR5 RCP scenarios. (In order to get the SSP scenarios to line up pretty well with the actual emissions in the early years I had to subtract the SSP land use CO2 emissions from the SSP total CO2 emissions values).
While an emissions scenario like SSP5-8.5 has been widely used to scare humanity with climate model projections of extreme warming, this plot shows the last several years of global emissions (through 2023) suggest the future will look nothing like that scenario.
(And, it should come as no surprise that “Net Zero” emissions by 2050 is a delusion.)
I encourage everyone to subscribe to Pielke’s The Honest Broker substack, where he discusses this and related issues in great detail.
How do we measure global fossil fuel CO2 emissions? Reports from individual nations? Atmospheric CO2 concentration?
Just measuring how much gas/oil/coal was produced is a pretty good estimate. Those numbers have to be accurate for tax reasons. Fudge on them and people end up in jail.
That works for public companies reporting on a GAAP or equivalent basis. Most state-owned natural resource ‘companies don’t.
Global fossil fuel CO2 emissions (however calculated) do not equal CO2 mass that remains indefinitely in Earth’s atmosphere. Period.
The notion of “indefinitely” comes from the physically impossible IPCC Bern model requirement that the two sources of CO2 (anthropogenic and natural) have different atmospheric residence times. These results are contrary to studies (e.g., Berry) that reflect physical reality and show that the e-time for both is on the order of 5 years.
Just so.
5 years. Indefinite. LOL.
Apparently I need to clarify my comment: it was to assert that any CO2 emissions from man’s use of fossil fuels (along with CO2 emissions from cement production, not mentioned) do not have the characteristic of remaining in Earth’s atmosphere indefinitely.
It is, as Ollie posted, transient in the atmosphere such that accumulation of man’s CO2 emissions is a misnomer.
I don’t think Net Zero by 2050 is delusional it is after all “NET” Zero. Producing no more annually than the carbon sinks can remove.
Actual zero is certainly undoable but Net Zero is really nothing more than Creative Bookkeeping
Many are now calling for better than net zero. Here in Wokeachusetts, this is a new plank in the climate cult dogma- and to get better than net zero, they want to lock up the forests.
Well, they could lock up the beaches, but that’s where the progressives live and vacation.
Surely there are also sampling times and intervals that determine whether a state of “net zero” equilibrium prevails?
I’m afraid that the equilibrium you speak of is spongy or springy.
20 GtCO2/y will stabilise CO2 levels in the atmosphere, let’s see if peak emission will be reached in the next decade, however, given the rising demand in Asia and Africa, this will be unlikely.
An analysis of the global CO2 emissions and the concentrations at Mauna Loa from 1959-2022 shows that the natural CO2 emission rate (excluding human emissions from fossil fuels) is about 40 Gt/yr, and the natural sink rate depends on concentration (-0.14 Gt/yr/ppm).
So we get equilibrium, or “net zero increase in concentration” when
E + 40 – 0.14 C = 0
where E = human CO2 emissions in Gt/yr, and C is the eventual equilibrium concentration in ppm.
If human CO2 emissions stabilized around 40 Gt/yr (implied by the green line in the above graph), the future CO2 concentration would stabilize around 571 ppm, but would take over 200 years to reach this value.
It should be noted that the rate of increase in human CO2 emissions slowed down in 2012, and has been about 0.24 Gt/yr^2 since then. Also, the rate of population increase in the world has slowed since 2018, and the CO2 emission rate per capita has decreased since 2012. A continuation of these trends would lead to a future emission rate below the green line.
Unfortunately, the sinks don’t sequester a fixed, absolute amount. The removal is a percentage that is a function of the partial-pressure difference. Therefore, if the anthropogenic emissions decline, the sinks will take up less than the amount of the decline.
As stated before, the sink is linear proportional to the atmospheric co2 gradient, if CO2 stabilises at 40 GtCO2/y Concentration stabilises at 540 ppm
Like I said…it will take creative bookkeeping to infer net zero
They do seem to sink whatever monies the current administrations throw at them though
I would expect the rate of chemically “sinking” atmospheric CO2 (from whatever sources) into the world’s oceans to indeed be linearly dependent on the partial pressure (i.e., ppm) of CO2 above their surfaces.
On the other hand, I expect the biological “sinking” of CO2 (aka the “greening” of Earth) happens on an exponentially decreasing curve, although I don’t know what the asymptotic limit might be . . . maybe as high as 1,200 ppm based on the average target used by many greenhouse growers, maybe as high as ~7,000 ppm based on paleoclimatology proxies from the Cambrian period of Earth’s history.
The “biological” rate of conversion of CO2 to bicarbonate by carbonic anhydrase (at the ocean-atmosphere interface) is roughly one million to ten million times faster than the uncatalysed chemical reaction.
It’s the basis of an excellent, simple, visual demonstration in the lecture theatre for undergraduate bio-inorganic chemistry classes, illustrated by a pH dye.
I’m confident climate models don’t take account of this variable rate in their carbon-cycle modeling. In their assumed model world sand would also quickly dissolve in fresh water and trees would spontaneously burst into flame even in a Siberian winter.
Just because something can happen, thermodynamically, it doesn’t mean that it will happen at the rate blithely assumed by models.
What about the biological rates of conversion of atmospheric CO2 into carbohydrates?
It happens on land with plants, lichens (a symbiotic combination of land algae and fungus) and cyanobacteria and in waters with algae (including seaweed and kelp, both macroalgae) and phytoplankton.
Australia, according to our ‘esteemed scientific authority’ the CSIRO, is a CO2 sink, as is the Southern Hemisphere.
Regardless, our CAGW-crazed politicians of all stripes are still trying to lower our emissions, regardless of the consequences.
See https://capegrim.csiro.au/
Worse, the closer the US Or the EU, GB, Etc., gets to Net-Zero the More that manufacturing increases in China canceling out all decrease of CO2.
And without the benefit of cleaner energy (not necessarily CO2 cleaner as CO2 isn’t really a pollutant) and actual environmental controls
Bryan:
Lol. The climate alarmists are masters at creative bookkeeping!
NetZero by 2050 is delusional by any economic or practical metrics.
The worldwide costs were estimated to total ~ $270 trillion by McKinsey. Co.
https://www.mckinsey.com/business-functions/sustainability/our-insights/the-net-zero-transition-what-it-would-cost-what-it-could-bring
The process would require a totalitarian reordering of society with marked loss of individual rights and worsening of living standards. What country’s citizens would vote for that?
Guess which country is expected to pay for most of these trillions? These numbers require all projects to be built on-time, on-budget, and work just as predicted. And no free-loading countries!
IIRC, Bloomberg NEF estimated it at over $200T.
My septuagenarian’s observations about scares throughout life –
So if A.I. could be applied to implant a septuagenarian’s “scare-o-meter” into younger minds, maybe the climate hobgoblin could be summarily dismissed?
Well, H.L. Mencken, American journalist and essayist, summarily dismissed governmental-fronted hobgoblins thusly nearly 100 years ago:
“The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, all of them imaginary.”
I updated Mencken’s brilliant quote for the home page of my blog:
The Honest Climate Science and Energy Blog
Climate change + Nut Zero = Leftist Fascism.
Leftists gain power by keeping people alarmed, and demanding to be led to safety, by scaring them with a series of imaginary boogeymen. Including CO2, Big Oil, Donald Trump, Russians and rural white Americans.
There is no climate crisis or any need for Nut Zero (energy mandates, subsidies and tax credits).
You probably would like this.
https://rumble.com/v54n7rp-david-sacks-explains-the-evils-of-the-democrat-party.html
The real scary thing is what western governments want to do to combat the total non-problem of “climate”.
After a short search, an SSP is a Shared Socioeconomic Pathway LINK
Some Stupid Policy doesn’t even need a search,
Nor does
Scared Stupid People
They’ll claim it is only due to their draconian efforts that we have averted Armageddon and that this proves we need to do more.
Yes, yes. And imagine how much scarily hotter it would have been without all those two weeks to flatten the curve(s).
Not to mention all those jabba jabbas that stopped the seas boiling.
Or something like that, anyway.
The only thing higher than the IPCC projections are the people responsible for them.
The “ClimateCult™ rush forward toward an unseen cliff. A few are beginning to sense it is out there – what will they do? Many will simply disappear as though they have vanished over a real cliff.
Climate-Crisis skeptics see a wall and have for years.
The former have never trusted Roy, but I do.
The fact that there are multiple IPCC reports at all is what is scary. All talk from those who vigorously support an unelected “New World Order” and “One World Government” is really about as scary as it can get.
Even worse is the amount of taxpayer funds that go into supporting the ever growing pile of crap that is contained in the IPCC reports. On the plus side there are fewer trees being wood chipped to provide paper for the reports. If they were printed, they would be metres high.
You now need a fast computer just to do a search on the electronic reports.
They are bullshit pilled upon bullshit, all based on a fantasy. The author, Roy Spencer, depends on keeping that fantasy going for his livelihood but he is doing honest work that is of some benefit in understanding Earth’s climate.
I like the SSP8.5 scenario because it highlights a fundamental flaw in all the models. All models produce ocean surface temperature sustaining more than 30C using the SSP8.5 scenario and that is sufficient proof that they are garbage.
So they are lying and have been lying. Got it. Co2 is plant food. Period. Full stop. More Co2 is good, less is bad. Mmmkay?
And what if the plants gain a majority and take over everything?
Cool! A situation I deal with routinely! I am a regular practitioner of chemical warfare against the plant onslaught!
Triffids?
Love Death and Robots
The day the Yogurt took over
The vegetables are already running the governments.
Biden proved that at the debate
Didn’t you see the article posted prior to this one? Weird Vegetables are growing limbs and plotting to take over.
Of course, as I’m sure Dr. Spencer knows, there is no scientific preponderance of evidence—let alone scientific “proof”— that atmospheric CO2 concentration levels above about 300 ppm have any significant effect on global temperature.
Therefore, why the IPCC should be “worried” about current or future CO2 emissions from human activities is not worth the electrons that are moved around to discuss the matter in the first place.
“that atmospheric CO2 concentration levels above about 300 ppm have any significant effect on global temperature”.
That conservative CO2 is saturated myth is repeated so often that I had to write an article to refute it. You won’t read the articles … but it’s not a crime to remain clueless.
The Honest Climate Science and Energy Blog: The Greenhouse Effect: The CO2 is Saturated Myth
Against my better judgement, I decided to read your ‘explanation.’ I wasn’t surprised. As in the past, it is largely a qualitative explanation that doesn’t adequately take into account the concept of “negligible.” I could criticize more, but it isn’t worth my time.
Says the AGW-zealot that cannot produce any evidence whatsoever to back up his AGW-mantra claims.
If it was a crime to remain clueless.. you would be doing a life sentence.
He is!
Hmmm . . . let’s see . . . a Mr. “Richard Greene” against the likes of Professor William Happer and Professor William van Wijngaarden in comparison for writing scientific articles about atmospheric physics?
Game over.
It isn’t scary if it isn’t SSP5-8.5
Anything else just won’t do.
Given that the total warming from doubling CO2 over preindustrial levels (~560 ppm) is expected to result in around 1⁰C warming just from radiative forcing (without feedbacks), and given that we’re nowhere near 560 ppm in the atmosphere at the moment, it’s safe to say that the CO2 existential threat doom fantasy has been cancelled…
Even with water vapor feedback turned on by selecting “fixed Relative Humidity” in Modtran, you only need about a degree of surface temp offset to balance outgoing and incoming solar per doubling of CO2…so you are correct….the CO2 existential doom is centuries into the future, if it exists at all before fossil fuels become an outdated method of energy production. One should be much more worried about politicians dreams of taking over Taiwan, South Korea, Ukraine, Middle East…..any of which can be 25 minutes away from significant loss of human life…much bigger and more real than climate related statistical deaths.
Atmospheric CO2 is rising at about +2.5 ppm a year. At that rate it will take 168 years for CO2 to double from 420 to 840 ppm
The ACTUAL TIMING of CO2 x 2 IS A GUESS
The important number is how much a dooubling of CO2 plus various feedbacks will affect the global average temperature in 100 to 200 years.
No one knows
Guesses range from +0.5 to +5 degrees C.
The growth rate of CO2 does not affect the guesses of what CO2 does to the climate in the long run.
The growth rate of CO2 only affects how fast the atmospheric CO2 level will double.
If Nut Zero has any effect on CO2 emissions, they might be less than a +2.5 ppm increase of atmospheric CO2 every year. On the other hand, developing nations using more coal might increase the CO2 rise rate to +3 ppm a year.
I am certain the future climate will be warmer,
unless it is cooler … but I prefer warmer.
“No one knows”
And no-one has any evidence it is anything but basically zero…
… immeasurably small and insignificant.
Warming by atmospheric CO2 has never been measured anywhere on the planet.
I do. And you will to if you take a few minutes to understand what I write here.
Atmospheric carbon addition’s direct contribution to temperature is to increase atmospheric pressure. That increases is unmeasurable. Therefore the temperature increase from CO2 is unmeasurable.
Earth’s radiative energy balance is set by the temperature regulation of ocean surface to a sustainable limit of 30C. There is proof of that every day somewhere over tropical ocean. The process control is very powerful with a negative feedback of 2. Once 30C is reached due to cyclic convective instability the ratio of reflected short wave increase to reduction in outgoing long wave is 2.
The operation of the process is a function of surface pressure and is easily observed at the tropical moored buoys and longer term trends per this chart; specifically just north of the equator:
?ssl=1
The ITCZ is migrating northward as the peak solar intensity increases in the NH and more of the tropical ocean in the NH is going into regulation mode. The increasing cloud over this region is increasing SWR while the OLR is reducing. The ratio of long term average is closer to 1 than 2 but when in regulating mode above 30C ocean, the ratio is 2. That ratio is sustainable rather than cooling because the warm pools create mid level convergence and high level divergence so draw in latent heat from surrounding ocean during the cyclic convective instability. The warm pools create the Hadley cells that power the atmospheric and ocean surface circulation.
The 30C regulating limit has been well known for decades but the IPCC and their co-conspirators have attempted to bury the information. Their livelihoods depend on keeping this knowledge from the wider public. Very few people understand that it is impossible for open ocean surface to sustain more than 30C. Fools talking about ocean boiling prove themselves fools.
Wrong. Scientific estimates range from ZERO to +5 °C or higher.
The IPCC is proposing SSP 16.6
CO2 rising so fast you can see it rising
Up +1ppm a week.
IPCC demands global martial law to stop certain overheating, and $200 trillion dollars for further studies, with 10% to Joe Bribe’em.
Geez Richard…..the Grauniad will publish your sarcasm and call you a “well known climate expert”. Of course leaving out the last Joe Brib’em comment.
“CO2 rising so fast you can see it rising”
Ah.. the Greta syndrome… 🙂
The curves on those graphs involve CO2 moving between sources and sinks that have very simple broad definitions, like one is a place putting CO2 into the air and the other is a place removing it.
Measurements to class as sink or source are kind of static, typically being concentrations at a time. I cannot tell a sink from a source by looking at a global map of CO2 levels in the air on a specified date. I need a dynamic measure, the rate of change of CO2 in the air, as a minimum. It then helps if there is an associated process, such as uptake of CO2 by a forest (that then gets complicated).
Help about residence time concepts came from bomb test isotopes, but there is still argument about what they mean.
After this verbiage, the question is, how does one measure where there is a sink or a source; and how fast the action is?
Some places might have source and sink mechanisms operating simultaneously.
If you cannot quantify movement (apart from isotopes) how can you state that human CO2 emissions are X, Y or Z% of the movement? What am I missing? Geoff S
That is almost always the case. In the Summer warmth, bacteria and fungi are pumping out CO2 and CH4 at a rate limited by water and nutrients, but still can’t overpower the photosynthesis of plants and phytoplankton drawing down CO2. Only in the dead of Winter nights does photosynthesis shutdown at high latitudes, while plants respire and decomposers continue to pump out CO2, albeit at reduced rates from the Summer highs. However, the tropical photosynthesizers operate year round in the same manner as those at higher latitudes. It is not a binary process. Its a system where the equilibrium shifts between emission and sequestration.
The bomb test isotope was C14. Assumptions were then made about C12, C13 ratios from burning FF, were widely accepted, but were never actually tested. Is it possible to debunk this first empirical study which concludes, among other results, that “no signs of human (fossil fuel) CO2 emissions can be discerned”? It would be very interesting to see a proper analysis of the study by someone with an adequate background and mathematical skills.
https://www.mdpi.com/2413-4155/6/1/17#B31-sci-06-00017
A much simpler summary
https://rclutz.com/2024/03/20/humans-add-little-to-rising-co2-march-2024/
Very nice Dr. Spencer, I agree with you the UN IPCC is putting out exactly the information they want us to have. In my view they have very little concern whether that information is truthful, honest or correct.
This article is wrong-headed. SPC 85 had a definitive purpose — and not what the author claims. It was to serve as a reference pathway to the highest conceivable atmospheric concentration, for comparison against a variety of realistic scenarios. The authors are typical of WUWT bloggers –looking for conspiracies everywhere.
EDIT –
“SPC 85 had a definitive purpose”
To spread as much BS as they can possibly manage.
The beetroot is typical of all AGW-clingers, and cannot see the scam in front of his nose.
None of the “scenarios” are ever going to give anything “realistic, because they are all based on rancid, AGW anti-science.
No the range of error is massive for that stupid 8.5 SCENARIO as reality is so far below that absurdity that it was a waste of time.
However, SPC is labelled as “business as normal”. Doesn’t seem to agree with your ideas as stated. It is used regularly to support the claims of excessive warming, the cause of Climate Change and leads to the existential threat. It may have been developed as a maximum reference point, but is used as the expected scenario. This isn’t a conspiracy perceived by WUWT bloggers – it is the reality of Climate Science.
An extract from the Meinshausen et al (2024), “A perspective on the next generation of Earth system model scenarios: towards representative emission pathways (REPs)” paper.
The IPCC WG-III scientists admit issues with the media reporting of RCP8.5 and SSP5-8.5 as “business-as-usual” scenarios / pathways, and propose ways to (try to) avoid that in the future.
As for the rest, people are free to “read into it” whatever they want.
Harold the Organic Chemist Says
ATTN: EVERYONE!
RE: CARBON DIOXIDE DOES NOT WARM THE AIR!
Using Google. you should search for “Still Waiting for Greenhouse”.
This the website of the late John Daly.
On the home page, scroll down to the end and click on “Station Temperature Data” On the
“World Map”, click on “North America” and then “Pacific”. Finally, scroll down and click on
“Death Valley”.
The figure shows plots of the average annual seasonal temperatures and average annual temperature. The plots of the temperature metrics are fairly flat. This means that the increase
in CO2 from 1923 to 2001 did not cause any heating of the air. In 1923 the concentration of
CO2 was 300 ppm by volume. In 2001, the concentration of CO2 at the MLO was 370 ppm
by volume.
John Daly found many weather stations around the world whose annual temperatures have
not changed much since the during the 1900’s and into the 2000’s. The average annual
temperature at Alice Springs, Aus. has not changed much since 1879.
At the MLO in Hawaii, the concentration of CO2 is 427 ppm by volume. This is only
0.839 grams per cubic meter air. At 20 deg. C, the mass of 1 cubic meter of air is
1.20 kilograms. This small amount of CO2 can only heat up such a large mass of
air by only very small amount.
At 21 deg. C and 70% RH, there is 14.3 grams of water vapor per cubic meter of air.
Water is 98% of the “greenhouse effect”.
Snice 1988, the claim by IPCC that CO2 has caused “global warming” has been a lie
and they are still lying.
Harold, “This small amount of CO2 can only heat up such a large mass of
air by only very small amount.”
Intuition agrees.
But what is that small amount?
It can be calculated from quantum physics.
The average number of phgoton intersctioons per unit of time can be calculated for a given temperature.
The energy moved to the molecule each time can be calculated, Planck.
Making assumptions about where that energy goes, integreted over time, can be found.
I’m instead looking for a section on this in IPCC stuff. Anyone have useful links?
Two complications arise. The IPCC thenenters another energy relm by their water vapour feedback assumptions, to produce the hot spot near the toppopause that nobedy can find. Plus, instead of working in ordinary units, people wander off into doublings of concentration to show that they are uncertain and want to bypass some fundamentals. Like, should the first CO2 doubling be from 1 to 2 molecules?
Blogger Dr Strangelove provided this.
Dr. Strangelove
March 30, 2018 at 11:00 pm
“There is only one way that temperature can increase and that is for the translation velocity of the molecules to increase. It can not be shown that the IR absorbed by a CO2 molecule is sufficient to do that. The mass of CO2 molecule is too high.”
This is wrong. IR can easily increase gas temperature.
Energy of 15 um IR photon from Planck’s law:
E = h c/w = 1.32 e-20 J
where E is energy, h is Planck’s constant, c is speed of light, w is wavelength
Kinetic energy of CO2 molecule:
E = KE = 1/2 m v^2
m = M/N
where KE is kinetic energy, m is mass of molecule, v is velocity of molecule, M is molar mass of CO2 = 44 g/mol, N is Avogadro’s number
Solving for v^2
v^2 = 2 E/m = 3.6 e5
Mean kinetic temperature of gas from kinetic molecular theory:
T = v^2 M /(3 R)
where T is mean kinetic temperature, R is ideal gas constant
T = 635 K
You see there’s enough energy in IR to increase gas temperature. CO2 is only a trace gas in the air that’s why we don’t get this high temperature
Geoff S
Except IR absorbed by CO2 valence electrons does not alter the momentum of the CO2 in motion. Therefore CO2 does not “thermalize” IR. IR is not thermal energy, it is electro-magnetic energy.
Temperature is the average kinetic energy of molecules in motion. Kinetic energy in motion has momentum. If the momentum is not changed, the temperature is not changed.
There is a small amount of momentum exchange between a molecule and an EM wave. A photon has no rest mass, but energy in motion has momentum, so an equivalent mass for photons in motion can be calculated. Thermal conductance is the exchange of momentum by molecular “collisions.”
The IR is not “absorbed by CO2 valence electrons”, the molecules vibrate in two bending modes and that energy is transfered via collisions to the neighboring molecules thus increasing their kinetic energy in about a few nanoseconds. CO2 absorbs about 10% of the IR emitted by the surface and that energy is converted into the atmosphere’s kinetic energy as I described.
As I said, there is only 0.839 grams of CO2 per cubic meter air when the concentration
of CO2 is 427 ppm. For air at 20 deg. C, 1 cubic meter has a mass of 1.2 kilograms.
When CO2 absorbs IR light, it undergoes vibrational excitation but then undergoes very rapid collisional deactivation. This results in the transfer of vibrational energy to the colliding molecule whose velocity increases. The temperature of the gas then increases by small amount.
For the weather conditions in the example above, there is 14.3 grams of water per cubic
meter of air. Water is 98% of the greenhouse effect.
We do not have to worry about CO2.
They big mad. Hilarious. No arguments. No worldview. No nothing.
Harold the Organic Chemist Says:
ATTN: Moderators
What happened to my comment which I posted earlier today? Why did you remove it?
Everyone knows the IPCC is perpetrating scientific fraud and their claim that CO2 is the cause of
the recent “global warming” is a lie.
Harold the Organic Chemist Says:
I am amazed: My previous comment has reappeared!
Not sure about “good”, but the graph below uses the GCP (Global Carbon Project) CO2 emissions numbers up to 2023 “as is / without question” for comparison purposes.
While up to 2014-ish people could claim that “RCP8.5 is the closest to reality” the graph clearly shows why even the IPCC, in the AR6 WG-I report, had to admit that SSP5-8.5 and SSP3-7.0 … and, by inference, RCP8.5 … can only be described as “counterfactual”.
It also shows that the near-term “business as usual (BaU)” pathways are SSP2-4.5 / RCP4.5.
A reminder from WG-III (Mitigation), the Working Group that produces that various “pathways” that are used as inputs to the climate models used by the WG-I (Scientific Basis) report.
AR6, WG-III, FAQ 3.3, “How plausible are high emissions scenarios, and how do they inform policy?”, on page 386 :
RCP8.5, SSP5-8.5 and any future equivalents dreamed up for the CMIP7 / AR7 cycle (REPs, or Representative Emission Pathways ?) are “very useful”, but shouldn’t be presented as “BaU” by either social or mainstream media outlets.
Good luck with that hope !
We all know the misuse of numbers is constant and ongoing. There were 85,000 attendees at COP 28, most of them influential and salary dependant to some degree on the scam continuing indefinitely. They do not care about the rest of the people on the planet. The only pertinent question is how to reverse the flow? These parasites need to see career advancement in the truth. How can that be achieved?
Actual: 40,000 MMt, totalitarian# 120,000 MMt =300% too high.
1990 IPCC 25yr forecast 300% too high measured against two independent empirical measurement (this forecast was made as an average of over 30 models ranging as high as 600% too high).
Actions to correct models: double down on the erroneous models. Move goalposts, jigger GISS, HADCRUT, etc thermometric readings, replace with experts’ evaluations.
The IPCC is a bit bi-polar. In its latest report one part said that RCP8.5 should not be used but another part cited many papers that used it.
The problem is that egotistical researchers use RCP8.5 so they can produce media releases that say “as much as” about anything negative about their projections. Relatively little research seems to be done using more moderate RCP scenarios.