C13(The Earths Atmosphere) Flashcards
The earths early atmosphere was formed by ….
Volcanic activity
How was the early atmosphere formed
volcanoes released carbon dioxide, water vapour and nitrogen and these gases formed the early atmosphere
How were Earths oceans formed
-water vapour in the atmosphere condensed as the earth cooled down
-which caused water to fall as rain over millions of years
-water was collected in hollows in the crust as the rock solidified
-which formed the oceans
In earths early atmosphere the main gases were …
-Carbon dioxide
-ammonia
-methane
-water vapour
How was oxygen formed in the atmosphere
-2.7 billion years ago algae evolved
-algae used energy from the sun to produce food by photosynthesis
-this produced oxygen gas as a waste product
-over the next billion years the levels of oxygen increased steadily as the algae thrived
-more plants evolved, all of them were photosynthesising, removing CO2 and making O2
How was the carbon dioxide reduced in the atmosphere
-photosynthesis by algae and plants
-the formation of sedimentary rocks and fossil fuels trapped carbon
-carbon dioxide dissolved in the water of the oceans
How was ammonia and methane reduced in the atmosphere
By reactions with oxygen
The levels of nitrogen in the atmosphere increased by …
-volcanoes
-nitrogen gas is a very unreactive gas so it was not reduced in the atmosphere
What are the gases that form our modern atmosphere
-nitrogen = 78%
-oxygen = 21%
-argon = 0.9%
-carbon dioxide = 0.04%
-trace amounts of other gases
What are the main greenhouse gases in our atmosphere
-carbon dioxide
-methane
-water vapour
What are greenhouse gases
Gases that absorb energy radiated from Earths surface
How does the greenhouse effect work
-the greenhouse gases let short wavelength EM radiation from the sun pass through to warm up the planet
-the surface of the earth cools down by emitting longer wavelength infrared radiation back into space
-greenhouse gases absorb the infrared radiation being reflected which causes thermal energy to get trapped in the atmosphere warming it up
What are the consequences of global climate change
-rising sea levels
-extreme weather events
-changes in temperature and amount of rainfall
-endangerment of species
What is the carbon footprint
The total amount of carbon dioxide and other greenhouse gases emitted over its full life cycle
How is sulfur dioxide formed
Oxidation of sulfur impurities
