> parts of the Mediterranean are estimated to have been 2°C hotter than today.

That's not a change in global average tempreture though, that's a local variation.

> but the climate had constantly changed throughout history.

'History' is written history, and no, global climatic parameters haven't changed in written history.

I believe you might be thinking of geological time - and yes, on long time scales climate has changed - and changed with cause just as a stone moves subject to force.

In this particular moment of time climate has started to change within the past century after remaining stable for tens of thousands of years and the root cause of that change is human activity changing the insulation properties of the atmosphere.