I'l love it when people tell me ice core samples have all the answers

I NEED A SUPPORT PIECE ON MAN MADE GLOBAL WARMING, FOCUS ON ICE CORE SAMPLES, THAT TELLS THE WHOLE HISTORY OF THE PLANET; BUT THEN HOW DO I ACCOUNT FOR THE DATA DURING THE MESOZOIC ERA? MESOZOIC ERA? WHAT? DON'T GO GETTING ALL SCIENCEY ON ME BOY! NOBODY CARES ABOUT ACTUAL SCIENCE!