9. Earth's atmosphere Flashcards
What is the percentage of nitrogen, oxygen and carbon dioxide in our atmosphere?
Nitrogen = 80%
Oxygen = 20%
CO2 = 0.04%
What was the early atmosphere composed of?
Mostly carbon dioxide
How did the oceans form?
Water vapour condensing as the earth cooled
How did the amount of carbon dioxide in the atmosphere decrease to today’s levels?
Dissolved in the oceans
Photosynthesis
Converted to fossil fuels
Precipitated as insoluble carbonates
What is a greenhouse gas? Give three examples
Gas that traps radiation from the sun. Examples = methane, carbon dioxide, water vapour
How have humans increased the amount of carbon dioxide in the atmosphere?
Burning fossil fuels and deforestation
How have humans increased the amount of methane in the atmosphere?
Rice farming, cattle farming
What is global warming?
Increase in average global temperature
What is climate change?
Change in long-term weather patterns across the planet
What are effects of climate change?
Sea levels rising, extreme weather events, changes in rainfall, changes to ecosytems, polar ice caps melting
What is a carbon footprint?
Amount of carbon a product, process or person releases into the atmosphere over its lifetime
How is carbon monoxide formed and how is it dangerous?
Incomplete combustion; toxic gas
How are carbon particulates formed and how are they dangerous?
Incomplete combustion; global dimming, respiratory problems and possible carcinogen
How is is sulphur dioxide formed and how is it dangerous?
Sulphur impurities in fossil fuels react with oxygen during combustion; acid rain and respiratory problems
How are oxides of nitrogen formed and how are they dangerous?
Oxygen and nitrogen react in the heat of a combustion engine; acid rain and respiratory problems
