one thing that is good at demonstratin the tempature and co2 lvls are plants. some type of plants cant grow in high co2 lvls, and others cant grow in low co2 lvls. they are also the ones that grow in warmer climes and colder. by find out what plants grew at what time and what areas they can get a good picture of co2 and tempature lvls.

the more man learns, the more he realises, he really does not know anything.