Dale Cloudyman Profile picture
Oct 26 23 tweets 12 min read Twitter logo Read on Twitter
The core premise of the AGW hypothesis is higher CO2 levels --> to higher global temperatures.

Yet this is *completely unsupported* by any experimental evidence!

Worse, it is ultimately only validated *by circularly assuming* the premise is true!

A thread... 👇🧵
Image
We start with the latest publication at time of writing, the IPCC AR6.

In Chapter 7 (…) they summarize how higher CO2 levels lead to higher equilibrium temperatures.

Climate is affected by perturbations to the 'energy budget', quantified by ERFs.

1/ ipcc.ch/report/ar6/wg1…
Image
The climate system's response to these ERFs is assessed as the Equilibrium Climate Sensitivity.

The equation is given below, relating the ERF from a doubling of CO2 concentration, to the ECS:

ECS = –ΔF2xCO2/α

2/
Image
Image
So the concentration of CO2 directly translates into an ERF, which is then used in a further equation to determine how much this will affect global equilibrium temperature.

ECS is fixed for a given ERF (doubling of CO2) but derives from Equation 7.1 with ΔN = 0

3/
Image
Image
The total anthropogenic ERF is given as 2.72 W/m^2.

The question is: *how is this model validated* such that we know it corresponds to reality?

Before answering, one must understand what an experiment is -- for detail, see the quoted thread.

4/



Image
The key is to keep in mind that we are looking for experimental evidence -- no amount of calculations, modelling, or observations can substitute for a controlled experiment demonstrating CO2 causing a surface to heat up.

With that in mind, let's see how the ERFs fare...

5/
In 7.3 ERFs are defined.

7.3.1 indicates ERFs replaced the SARFs (stratospheric-temperature-adjusted radiative forcing) of earlier assessments.

7.3.2 indicates ERFs are estimated using SARFs plus ESMs (Earth System Models)

Let's focus just on the SARFs...

6/

Image
Image
Image
7.3.2.1 describes that the SARF for CO2 in this AR6 assessment is based on a paper Etminan et al., 2016.

Now follows a long trail of citations. Keep in mind that at each step we are looking for the experimental verification of all this (see quoted post)

7/


Image
Etminan et al. 2016 () provides "New calculations".

They update the expressions from earlier work (Myhre et al. 1998) in "a number of important ways".

The methods section describes only calculations and simulations, not experiments...

8/agupubs.onlinelibrary.wiley.com/doi/epdf/10.10…



Image
Image
Image
We follow the citation to see how the earlier work was validated.

Myhre et al. 1998 () is... also "new calculations", using three "radiative transfer models".

They give no experimental validation of their new calculations...

9/agupubs.onlinelibrary.wiley.com/doi/epdf/10.10…

Image
They appear merely to refer again to earlier work, not providing any factual experimental evidence of why their models are valid.

Looking from AR4 (2007) through AR2 (1994) only yield references to AR1 (1990) (sub-thread: ).

So we go to AR1...

10/

Image
Image
IPCC AR1 Chapter 2 (), 2.2.4 describes the approach, expressing the forcing of each gas as a function of its concentration change.

This is calculated using "radiative transfer *models*".

No experimental validation of the models is provided.

11/ipcc.ch/site/assets/up…



Image
Image
Image
They refer to Hansen 1998 () for the coefficients, so we look there.

They do describe "experiments"... but, stunningly, they refer to running *model* simulations, not actual real-life experiments!

They describe model outputs and provide formulas...

12/pubs.giss.nasa.gov/docs/1988/1988…



Image
Image
Image
... but no experimental evidence.

They refer to a "paper 2" to corroborate the calculations, which is Hansen et al. 1984, so, we go even further back...

13/ Image
Hansen 1984 () is the first paper in this multi-decadal citation chain so far that offers something empirical to look at besides models.

The abstract says they "deduce an empirical climate sensitivity" to corroborate their 3-D global climate models.

14/pubs.giss.nasa.gov/docs/1984/1984…

Image
How do they validate their models empirically?

Their empirical estimations imply a sensitivity of 2.5-5°C for 2x CO2 if... ...

if ... ... if "the temperature increase is due to the added greenhouse gases".

... I will let that sink in for a moment.

15/
Image
...

...

...

16/ Image
For the starkest possible contrast, compare again this 1984 empirical validation () with the latest AR6 2021 report (), side by side...

17/ pubs.giss.nasa.gov/docs/1984/1984…
ipcc.ch/report/ar6/wg1…

Image
Image
We followed every citation. We looked at all cited evidence. We did not skip any steps.

In 30+ years of research, the only corroboration provided for this concept of RF, besides more models, is an assumption of that which is to be proven, i.e. that CO2 caused rise in temps.

18/
If the IPCC itself does not provide citations for experimental evidence... you can be darn sure it's because they don't have any.

That's it, folks. That is the entirety of what the AGW is based on. Calculations based on an initial 1984 assumption.

19/
And throughout the years, simply more observations, models, and calculations, all continuing with the (unproven) *assumption* that CO2 causes higher temperatures.

It is literally nothing but an assumed premise. A big hullabaloo. Much ado about nothing.

20/
This is why if you ask for experimental evidence for the AGW, you will either be derided, mocked, hit with "it's the consensus", or provided links that aren't actually experiments () or don't actually show the GHE ().

21/
pubs.acs.org/doi/10.1021/ac…
There is nothing underlying this theory, it all rests upon nothing.

As to why it is happening, why so many believe, why this wreaks so much havoc in the world... that is a topic for another day.

fin/

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Dale Cloudyman

Dale Cloudyman Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us on Twitter!

:(