Studies reveal that during colder glacial periods, co2 levels during warmer interglacial periods.

Studies reveal that during colder glacial periods, carbon dioxide levels were lower than during warmer interglacial periods. Glacial periods are intervals of time within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate between glacial periods. 

Nonmetals usually react by gaining electrons