When the terms calibration and homogenization are used in the same sentence with an obvious intent to try and mean/justify something then it's obvious those people are way way out of their depth and have absolutely no meaning or understanding of what BOM, NASA & NOAA have been doing in attempting to justify their man made climate agenda.
Ok, Let's assume that these three organisations actually are faking the temperature. They must also be faking everything else, lest physics make it obvious that it has been faked. Pressure, temperature, RH, wind are all interrelated by fluid dynamics. This means that all the upper measurements must be altered as well to ensure that lapse rates and all that stuff appear physically correct.
Now, apart of the three organisations you claim are involved, there are many other meteorological companies that provide services to argriculture ( including high precision local mapping of temperature and wind for planning pesticide spraying, or suing whomever caused the overspray that killed their crops), there are the airlines who rely on meteorology to calculate things like the maximum take-off weight and how much fuel to carry, etc). There are also Universities that run their own weather observation networks including surface & upper-air measurements, radars and other atmospheric sampling schemes. Defence also has its finger in the pie because meteorology is crucial for all war-fighters.
Since these organisations aren't en mass presenting cases which show that the readings are wrong and refusing to use "fake" data, one has to imagine that they must be in cahoots with the original conspirators.
Since planes use temperature to calculate things like maximum take-off weight, it must be getting the "real" readings from somewhere or wasting fuel (money). Airports publish this information for pilots to use. This means that either they revert to "real" data, or the equations used for the calculations are also "fake". If the "fake" data is used with real equations, then we should see planes arriving with more fuel that is required for safety and costing the airlines mega-bucks. This means that they would have burnt unnecessary fuel carry this unneeded fuel. They must be using the "real" data which also means that they must be in on the conspiracy. So, the web of the conspiracy just in each country is now simply huge.
Now, as you know, all the meteorological data is shared around the world and plugged into various models. So either the "fake" readings or the "real" readings are exported. If the latter, then it must be done in secret, otherwise the discrepancies would be seen and seen to be increasing. If this is the case, then all of the other meteorological organisations must also be complicit in the conspiracy.
So, let's that every government meteorological organisation in the world isn't complicit. This means that they get the "fake" data and plug it into their models. The output would show discontinuities at the Oz and US boundaries where the "fake" observations end. The output of these models would show that except for these "heat islands" the world is cooling. The models do not, in fact, say that at all. So we are back to every government meteorological organisation being complicit. Not only that that the complicity must spread to all the other Universities and private meteorological companies around the world.
So, let's run with all of the governments in the world knowing about this. The question is, given that that there are countries that hate the US with a passion - Iran being a good current example. The question must be asked, what are they getting out of it that would cause them to want to blow the US off the face of the planet, but not reveal that the BOM, NOAA and NASA are "faking it"?
So, we come down to (1) there is a conspiracy that needs to survive globally even with the most bitter hatred, or (2) there is no such conspiracy.
Such an implausible tale is not for me, but I'll leave you to believe that for unfathomable reasons this is only thing in the world that all governments can agree on doing, except perhaps fake moon landings as well.