evolution of the atmosphere

Question 1

what happened in the begining?

Answer 1

-volcanoes gave of gasses
-the earth surface was molten until things started to cool down
the early atmosphere was mostly CO2 virtually no O
-some ammonia and methane

Question 2

phase 2

Answer 2

-green plants evolved and produced oxygen
the died along with animals and as they buried this created fossil fuels and absorbed lots of carbon dioxide
-when we burn fossil fuels this ‘locked up’ carbon is released and the concentration of CO2 in the atmosphere rises

Question 3

phase 3

Answer 3

the ozone layer allows evolution of complex animals

• the build up of oxygen killed organisms that coudn’t tolerate it
• it also built up the ozone layer which prevented harmful rays reaching us