1. How can scientists tell what CO2 levels were like in the past? 2. How many years of record are preserved in the Antarctic ice core?

I give Brainliest!

1.Scientists can compare the amount of carbon dioxide in the atmosphere today with the amount of carbon dioxide trapped in ancient ice cores, which show that the atmosphere had less carbon dioxide in the past.

2.This is because the lack of melt at these locations does not corrupt the record of trapped gases or blur the record of other impurities. The oldest continuous ice core records extend to 130,000 years in Greenland, and 800,000 years in Antarctica.

Explanation:

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .