The high and rising costs of climate policy — now including the inability of jurisdictions that bet big on renewables to guarantee enough energy for their citizens to survive the coming winter — don’t just entitle us to question the basis for it: they demand we do so.
Ultimately, the justification for renewables is the view that carbon dioxide emissions have a big effect on the climate that will cause devastating harm at some point in the future. [bold, links added]
Scientists measure the effect using a concept called “Equilibrium Climate Sensitivity” or ECS, which estimates how much long-run average warming will occur as a result of doubling the amount of carbon dioxide in the atmosphere.
Some important new evidence pointing to a low ECS value just emerged in the scientific literature.
ECS has long been uncertain. In 1979 the U.S. National Academy of Sciences estimated it to be between 1.5 and 4.5 degrees Celsius, with a best estimate of 3.0 degrees C.
That range, which runs from “no big deal” to “very bad outcomes,” was accepted by the UN Intergovernmental Panel on Climate Change (IPCC) in its first report in 1990 and thereafter until 2007 when, citing greater warming projections in newer models, it raised the bottom end to 2.0 degrees C.
But over the next few years, literature developed using, not model simulations, but observed warming rates since the late-1800s to estimate ECS.
Its results typically centered around 2.0 C or less. So in 2013, the IPCC reduced the bottom end of the range back to 1.5 C and declined to offer a best estimate. In other words, after three decades climate science hadn’t narrowed the uncertainty at all.
The economic implications of ECS being 2 C rather than 3 C are enormous.
Economic models used by the U.S. Environmental Protection Agency and others assume ECS is 3 C when computing the social cost of carbon.
Some co-authors and I have shown that if the ECS parameter is instead centered around 2 C, the estimated social cost of carbon plummets and becomes very small at least through the middle of this century. The justification for costly climate policy essentially disappears.
Given the discrepancy between models and observations, the IPCC changed the way it handled the ECS issue in its latest (2021) report.
It no longer relied on model estimates, but neither did it go with the existing estimates in the empirical literature. Instead, it turned to a 2020 paper by Australian climate scientist Steven Sherwood and 10 co-authors, who used a new technique to combine data from modern climate change with that from the end of the last Ice Age and even further back.
They concluded the likely sensitivity range was from 2.6 to 3.9 C. On this basis, the IPCC revised its estimate of the likely ECS range to between 2.5 and 4.0 C with a best estimate of 3.1 C. And it specifically ruled out ECS being less than 2.0 C.
But as so often happens when a new paper appears in the literature that solves a political problem for the IPCC, they pounce on it before experts in the field have had a chance to check the numbers — which is what a new paper in the peer-reviewed journal Climate Dynamics by U.K. mathematician Nicholas Lewis does.
Lewis shows that the Sherwood paper made some mathematical errors and also relied on outdated data.
Interestingly, many of the data updates were done by the IPCC in other parts of its 2021 report but weren’t applied in the Sherwood study. Other data updates were done in the wider peer-reviewed literature by specialists in the field.
Lewis shows that correcting the math actually increases the sensitivity estimate slightly.
But updating the data does the opposite: the ECS best estimate drops to 2.2 C with a likely range from 1.8 to 2.7 C.
And if the analysis focuses only on the period after 1870 (recognizing that most of the world has little or no reliable temperature data prior to that) the best estimate drops even more: to 1.8 C.
In other words, with updated data, the Sherwood paper would largely confirm the empirical literature the IPCC had passed over.
This is a big deal. But amid the nonstop stream of climate news, you won’t hear about it: the world’s climate journalists aren’t trained to follow important topics like this — though that never stops them from lecturing their readers, viewers, and listeners about what to think about climate science.
It will be five years or more before the IPCC issues a new report. If history is any guide, months before that a group of authors heavily involved in the report-writing process will rush a paper into print that drags ECS back up to the 3 C range just long enough for the new IPCC Summary for Policymakers to declare the same old best estimate.
But reality keeps pointing to lower values.
Don’t let anyone tell you “the science” demands we simply accept the increasingly lethal climate policy agenda. It would fail a cost-benefit test even if ECS were 3 degrees C.
But it’s even less justified with an ECS of 2 degrees C, which is the level the evidence seems to insist on.
Read more at Financial Post
The above article assumes that carbon dioxide has a major influence on warming. The difference between the author and the IPCC is how much warming. However, it is unlikely that CO2 has much influence.
In the recent article on this website,
https://climatechangedispatch.com/going-to-court-over-the-science-of-global-warming/
is a graph showing that we are beyond the saturation point for CO2 warming. Most warming effect is in the first 20 ppm. By the time we get to 400 ppm, increase CO2 has a negligible effect.
This article misses most of the important points
ECS is just a guess, and requires several centuries, not in 50 to 100 years.
Many ECS guesses are based on very roughly estimated global warming since 1850 or 1880, when numbers were close to being guesses. Even if the numbers in the 1800s were correct, all the warming is assumed to have been caused by CO2, which is very unlikely, That means some ECS guesses are really worst case guesses, and also based on inaccurate temperature and CO2 level data. There were few weather stations in the 1800s and CO2 is estimated from ice cores before 1958.
The IPCC publishes another guessed number, TCS — the effect of CO2 in 50 to 100 years: TCS in IPCC’s AR6 (2021) was: +1.4 to +2.2 degree C.
More information on this subject:
https://elonionbloggle.blogspot.com/2022/10/climate-rap-co2-ecs-versus-co2-tcs.html
We’ve had forty years of 1.3degsC a century. Notrickszone website has 130 low ECS papers some suggesting 0.6degsC for a doubling of CO2. Take a bet that the 2016 El Nino spike will never be equalled for 30 years?
No one will notice because no one pays any attention to them.
As Prof. Ross McKitrick put it “According to the IPCC there is a ≈1% chance that an additional ton of Carbon will cause the Earth to become hotter than the Sun’s core”
Think about that for a moment – any model that can produce such an outrageous result (he’s not joking – it can) is obviously wrong !
Prof. Ross McKitrick’s off the cuff remark is in fact remarkably “conservative” – if you work back through the statistics of the IPCC feedback f given as 0.61 ± 0.44 for 99% confidence.
99% confidence equates to ±1.68σ therefore 1σ = (0.44÷1.68) = 0.262 equals one standard deviation (1.0 σ {Sigma}] .
Now the singularity (divide by zero problem) occurs when f = 1 or (1-0.61) = 0.39 greater than average of 0.61.
Which is 0.39÷0.262 = 1.49σ – which from stats tables is 43.2% of the area above average 50% – leaving 6.8% probability that the singularity can occur.
Like I said – outrageous – the IPCC is saying there is a ≈7% chance that we will detonate the entire universe !
(That is if you explore the equations further – they obviously don’t actually express it this way and would accuse me of deliberately misrepresenting their “science” but they chose to misrepresent the science – not me – I am merely showing you where that leads, to show that they are demonstrably wrong per impossibile if you follow their “proof” to its logical conclusion.)
“If you start an argument in a certain place and don’t go far enough, you can get any answer you want.” Richard Feynman
The problem with the IPCC amplification formula is that the models arbitrarily “drift” to various random values of f to produce a probabilistic value for the degree of heating we might encounter.
However this will give the model results a very large Hyperbolic upward bias (evident in the various graphic). This will also produce a great deal of “data” which is actually in the realm of impossibility. The upper limit of this model should be bounded by a maximum of 1 by the laws of physics – but of course any result that adds to the “evidence” for man made global warming won’t be excluded for such a frivolous reason as it actually being impossible.
The more you apply such a modelling process the higher your projections will be – this because a low random input value for “ f ” will be exponentially dwarfed by an equal but opposite high value for “ f ”.
To put that in perspective – repeated modelling will warm the planet – which I’m sure you will agree is preposterous.
The above article clearly shows the efforts of the IPCC to alter science to support the climate change narrative. This proves that they are a political advocacy group not at all interested in true science.
One item most people don’t know is that the climate change agenda is so expensive that it would fail a cost-benefit test even if ECS were 3 degrees C.
Why no mention of the UAH temperature data? Those numbers show that the warmists models run hot, not the atmosphere. I read something on the NASA website that said surface temperature records were valid because that’s where people live. Misinformation. Surface temperatures are higher because of the urban heat island effect, where people live surrounded by concrete and pavement. If there’s a greenhouse effect, it should show up in the atmosphere. The UAH satellites don’t support the warmist models so they dismiss them. They were put into orbit for a reason and the alarmists can’t handle the truth.
The IPCC is a bunch of political jerks spewing SHIT
over NOTHING
They feed of the UN budget and expense accounts
while doing and accomplishing nothing
but eating, slurping, sucking on the budget feed
that sustains their corrupt lives.
They know NOTHING
They have proved NOTHING
They have accomplished NOTHING
Yet they hold high unimpeachable authority
OVER EVERYTHING
Can you smell a phony ?