The ice cores are fairly reliable: https://www.bas.ac.uk/data/our-data/publication/ice-cores-an...

The ice cores appears somewhat reliable for certain questions, e.g. how high were the CO2 values in the winter on the poles 1000 years ago.

The link does not at all answer the main question for beginning to evaluate a temperature reconstruction of 125.000 years, that is: how well are the global annual temperature estimated from ice cores, for the years where we do have instrumental data?

In that link, it says ice cores track CO2. Temperatures were compiled from other geological records.

Ice cores are one of the data sources used in temperature reconstruction. From the linked page:

By measuring the ratios of different water isotopes in polar ice cores, we can determine how temperature in Antarctica and Greenland has changed in the past.

It's virtually certain this is good old propaganda

> I'm 'virtually certain' that data going as far as 125,000 years is not reliable.

There might be some truth to this, but A) the fact you don't bother quantifying varying degrees of reliability, and B) the fact that this is your immediate first reaction, makes me highly suspicious of anything you say.

> I work using wordpress and I've been working like this practically my entire career. I use programs like winscp to edit code directly in production over ftp or scp.

Ah well.