- the warming in the Medieval Warming Period is modest compared to projected modern warming
- The Alps are currently "warm enough" to be crossed without special gear much of the year. Otzi was found wearing multiple layers of hides and furs that would have provided good protection against the elements and is supposed to have been killed in late spring/early summer, not the depths of winter. Glaciers are active things and where he was found could be some distance from where he died.
- Yes the earth has been warmer and colder in the past, climate scientists are aware of these facts, it can also be true that climate is changing quickly in ways that may be very inconvenient for many modern humans.
- Regarding California climate, I don't know who "these same scientists" were, and popular press about climate change is often misleading and superficial. I have lived here for ~35 years and we have had a handful of very wet years but most of that period has been classified as "drought". Yes at the moment we are not but this was a very poor water year and we've benefited from carryover storage from last year. As far as I know, the scientific consensus is still that California is getting warmer and drier on average, and the large year to year fluctuations do not nullify that trend.