The +1.5°C cannot be attributed to the natural transition from an ice age. It is happening way too fast compared to the thousands of years the Milankovitch cycle operates on. Also, you're conveniently ignoring the fact that, if anything, the climate should be getting cooler, not hotter, as we are entering an ice age, not exiting one[1].

[1] https://en.m.wikipedia.org/wiki/Milankovitch_cycles#Present_...