C13 The Earth's Athmosphere Flashcards
What were the stages of the evolution of the modern atmosphere?
1) Frequent volcanic eruptions release gases such as H20,CO2,CH4,NH3
2) Frequency of volcanic explosions decreased - reducing earth’s average temperature
3) Water Vapour condensed to form oceans
4) Some gases dissolved in water - producing biological molecules needed for organisms
5) First organisms evolved to photosynthesise - so that CO2 decreases, O2 increased
6) Oxygen in the air reacted to form ozone layer - which blocks harmful UV rays
7) The earth turned into a bettee habitat so more advanced organisms evolved
8) Lighting and Microorganisms decreased NH3 and increased N2 and H2
How did Oxygen levels increase and Carbon dioxide levels decrease?
Early microorganisms and plants photosyntheseied rapidly to reduce CO2 level and increase O2 level
How did ammonia levels decrease and nitrogen/hydrogen levels increase?
Some microorganisms converted ammonia into nitrogen
Energy released by lightning was used to split amonia into N2 + H2
What are the greenhouse gases?
CO2 (Carbon Dioxide)
CH4 (Methanej
H2O (Water Vapour)
What is global warming?
The increase in the earth’s average temperature.
How do greenhouse gases warm up the earth?
When the shortwave IR radiation emmited from the sun reaches earth some get reflected back into space but a thick layer of greenhouse gases absorb the low energy IR radiation and reflect it back to earth (heating it up)
What are adverse affects of global warming? (Put 5 if you get atleast 4 correct)
Flooding
Ice caps melt
Poor growth of crops
Rising sea levels
Forest fires
Climate change
Extinction of species
Distribution of organisms will be changed
What are reasons for the increase in concentration of greenhouse gases?
- Increased use of energy by using non-renewabke sources
- Deforestation
- Cattle Farming
What is Carbon Footprint?
The total amount of CO2 and other greenhouse gases released by a product, event or service throughout it’s lifecycle
How can we reduce carbon footprint?
1) Increase the use of renewable and carbon neural sources
2) Carbon Capture
3) Carbon taxes
4) Energy Conservation (e.g.public transport)
5) Reforestation
What are problems with reducing carbon footprint?
1) Scientific disagreements
2) Economical Considerstions
3) Lack of awareness
4) Lack of international cooperation
How does CO2 pollute the atmosphere?
Its a greenhouse gas which can contribute to global warming
How does CH4 pollute the atmosphere?
It’s a Greenhouse gas contributing the global warming
Why is carbon monoxide bad?
Its a toxic gas which can displace oxygen from oxyhaemoglobin
Why is sulfur dioxide bad?
Some fossil fuels contain sulfur as impurities, it reacts with oxygen to form Sulfur Dioxide which is an acid gas.
This can cause acid rains which kill plants, animals and destroy buliding made of limestone.
