C13 - The Earths Atmosphere 2️⃣✅ Flashcards
What was the earths early atmosphere made up of?
About 95% carbon dioxide, almost no oxygen and a small amount of nitrogen.
What is the earths current atmosphere made of?
A very small % of carbon dioxide, around 80% nitrogen, 20% oxygen and little to no water vapour
How is it believed that the earth early atmosphere came to be?
Via intense volcanic activity that released gasses like carbon dioxide that formed the early atmosphere
How did the oceans form?
The little amount of water vapour In the earths early atmosphere started to condense as the earth started to cool down, ultimately making the water vapour into liquid water, forming our oceans
Why is there little no to water vapour in earths current atmosphere?
Because it all condensed into liquid when the earth cooled
How was oxygen produced in the early stages of the earth?
Due to oceans forming, simple plant life came to be. This simple plant life (algae) started to absorb carbon dioxide and undergo photosynthesis, ultimately producing oxygen.
Why did the earths atmosphere shift from mainly CO2 to O2?
Because the early plant life was absorbing the CO2 and producing O2, shifting the amounts of gasses to predominantly O2 rather than CO2
Other than via plant life, why did CO2 decrease in our atmosphere?
Sedimentary rocks formed, contains fossil fuels and therefore carbon, ultimately decreasing the amount in the atmosphere
What happened to the carbon in plants when they died?
They would sink to the bottom of the ocean, therefore trapping the carbon down under the ocean, decreasing its concentration in the atmosphere
What is the greenhouse effect?
The constant maintaining of the temperature of the earth by greenhouse gasses.
What are the main greenhouse gasses?
Methane, Carbon dioxide and water
How does the greenhouse effect work?
The sun emits short wavelength radiation which warms the earth
The earth looses the heat by emitting long wavelength radiation back up into space
The greenhouse gasses absorb some of the long wavelength radiation, re-radiating it back down to earth, consequently warming the earth so life can survive
Why is the greenhouse effect important?
Because it allows for the earth to be warm enough to support life
What is global warming?
When humans are increasing the concentration of greenhouse gasses in the atmosphere, therefore increasing the amount of heat re-radiated back at earth, warming it beyond its optimal level
How does deforestation increases global warming rates?
By cutting down trees reduces the ammount od CO2 absorbed from the atmosphere by photosynthesis