I have some very different opinions about "climate models".

There is no precise climate physics model to be the foundation for a real climate model.

Therefore, no real climate models can exist.

The things that are called climate models are just the opinions of the person/people who programmed the computer(s).

All models seem to assume CO2 levels are very important.

They ignore the fact that our planet had 4.5 billion years of NATURAL causes of climate change, with only one apparent connection to CO2 -- warming oceans, from natural causes, released some dissolved CO2 in the air, with a multi-hundred year lag. Vice versa for cooling oceans.

There are many climate models, but most seem locked into the 1970s -- assuming a 100% increase of the CO2 level will cause a roughly +3 degrees C. global warming, plus or minus 50%.

The plus or minus 50% makes me very suspicious of that "formula".

The next step is to examine global warming in the past century, to see if there a strong positive correlation with CO2 level changes.

It does not matter that models did not exist at the time, since we can apply their general temperature-CO2 formula to the very rough estimates of CO2 levels (from ice cores) before 1958.

Question:
Does the CO2 level act as a global average temperature "control knob" ?

With very little Southern Hemisphere temperature data, we believe there was global warming from 1910 to 1940, but with very little change in the CO2 level.

Weak positive correlation of average temperature and the CO2 level.


With rough global temperature data, we believe there was global cooling from 1940 to 1975, in spite of significantly increasing CO2 levels.

Negative correlation.


With good global temperature data, especially UAH satellites after 1975, 
there was significant warming and CO2 level increases, from 1975 to 2005.

Strong positive correlation.


From 2005 through mid-2015, lot's more CO2 in the air, but very little temperature change ( ignoring the temporary late 2015 / early 2015 EL Nino heat release, unrelated to CO2. )

No correlation.


So, since 1910, the correlation of the global average temperature and CO2 levels has repeatedly changed.

And there is no reason to be confident that CO2 levels control the global average temperature.

Even less reason to assume natural causes of climate change do not matter.


The so called climate models, therefore, are nothing more than opinions, that ignore climate history.

There are enough personal opinions, er, 
I mean climate models, to assure that at least one will seem to have made decent temperature predictions in past decades (i,e,;  The Russian INMCM model, now in the fifth generation (INMCM5), being developed at the Institute of Numerical Mathematics of the Russian Academy of Sciences.)

That does not mean future predictions from that model will be accurate.

It's easy to predict more global warming, after our planet has been warming (intermittently) since the 1690s.

That doesn't mean 
our planet will 
ALWAYS be warming.

In fact, ice core studies suggest our planet is rarely as warm and comfortable as it has been for several decades. 

The US stock market 
has been rising 
for almost 11 years.

That doesn't mean 
stock prices 
will ALWAYS 
be rising.