Where I live, in Europe, the climate has changed gradually during the last 4 decades from around 100 days with snow per year to only 2 to 4 days with snow per year.
This certainly does not look like a difference of one or two degrees per century. Regardless which is the actual increase of the average temperature, there can be no doubt that this is a dramatic change which will have unpredictable consequences and also that at least during the last few thousands of years there has never been a so great temperature change.