Atmosphere Flashcards
(36 cards)
When did the earth form
4.6 billion years ago
One theory suggests that early atmosphere came from…
intense volcanic pressure, which released gases into the atmosphere.
Three features of early earth atmosphere
Large amounts of CO2
Little or no oxygen
Small amounts of gases, such as ammonia and and methane
How were the oceans formed
Volcanic activity also released water vapour, which condensed as the earth cooled to form the oceans.
Why did nitrogen build up in the atmesphere
Because it is unreactive
How long have the relative proportions of our atmosphere been the same
200 million years
Our air % of different gases
80% nitrogen approx
20% oxygen approx
1% other gases
When did algae first evolve
2.7 billions
What did early volcanoes release other than water vaopur
Lots of carbon dioxide and some other gases
All the things early volcanoes released
Water vapour
CO2
Small amounts of methane and ammonia
What did the early atmosphere mainly consist of
98% C02
1% nitrogen
1% of other gases
At this stage, some of the _____ _____ ______ in the oceans to form a weak _____
carbon dioxide dissolved acid
How did oxygen increase
By algae performing photosynthesis. and by other primitive plants the amount of oxygen they made eventually built up and enabled animals to evolve
Formation of sedimentary rocks
Carbon dioxide is a very soluble gas. It dissolves readily in water. As the oceans formed, carbon dioxide dissolved to form soluble carbonate compounds. Then carbinated compounds where then precipitated as sedimentary rocks.
How did carbon dioxide decrease by formation of sedimentary rocks
It dissolved in water and formed soluble carbonate compounds and these precipitated into sedimentary rocks reducing the amount of carbon dioxide in the atmosphere
How was carbon dioxide reduced by living organisms
Absorbed from the oceans into photosynthetic algae and plants. Many of these organisms, and the simple organisms and the food chains that they are supported were turned into fossil fuels which all contain carbon.
How was coal formed
Coal being a fossil fuel was formed from trees which were in dense forests in low-lying wetland areas. Flooding caused the wood from these forests to be buried in a way that prevented oxidation taking place compression and heating over millions of years turned wood into coal
How were crude oil and natural gas formed
from simple plants and tiny animals which were living in oceans and lakes. These small organisms died and their remains sank to the bottom where they were buried under sediments the lack of oxygen prevented oxidation from occurring
Over millions of years, heat and pressure turned the remains of the organisms into crude oil.
Where is natural gas often found
on top of crude oil trapped under sedimentry rocks
Green house effect (6)
blurt rn bitch if u got it wrong
- electromagnetic radiation at most wavelengths passes through the earths atmosphere
- The earth absorbs most of the radiation and warms up
- The earth radiates energy as infrared radiation
- Some of the infrared radiation is absorbed by green house gases in the atmosphere
- The lower atmosphere warms up
Human activities contributing to green house effect e.gs
farming cattle releases methane
Farming rice in paddy fields releases methane
Burning fossil fuels in vehicles and power stations releases carbon dioxide
Deforestation releases carbon dioxide and reduces the absorption of carbon dioxide through photosynthesis
Why does not everyone believe humans are causing global warming
Because they believe the events are natural factors and cycles of climate change
Why can scientists not be certain about global warming
Climate change is complicated and it is difficult to predict and explain what will happen to global temps in the future. So scientists cannot be certain about global warming.
When evaluating the quality of the evidence on an issue like global warming what should you consider
Who did the research and whether they are trustworthy, skilled and experienced
Who funded the research, because that might cause some bias.
What methods were used to collect and analyse the data, because that might cause uncertainties in the evidence base.
Which organisation is reporting or publishing the evidence.