To my understanding, recorded temperatures don't go that long ago for us to use that alone and establish deviation from the real old past. And as said, the ava

To my understanding, recorded temperatures don't go that long ago for us to use that alone and establish deviation from the real old past. And as said, the availability of thermometers (specially in the oceans) has increased over time (i.e. more data coming in more recently). This should skew averages. Besides, the validity of thinking in averages in a pretty wild range of temperatures this planet demonstrates could be questioned anyway. Furthermore, cities have grown dramatically in the last century. Urbanisation creates more heat and thermometers in cities (which of course are used as a reference too), have been steadily reflecting that fact, obviously. But the problem is, discussing those things put you in the "petrol head" "let's pollute" field, which is definitely not my case. They are attempts to silence the discussion, in my view.