the earth's atmosphere Flashcards
what are the 3 phases of how the atmosphere evolved? (simply)
phase 1 - volcanoes gave out gases.
phase 2 - oceans algae and green plants absorbed carbon dioxide.
phase 3 - green plants and algae produced oxygen.
what happened in the first phase of the atomsphere?
volcanoes gave out gases.
1. volcanoes erupted and released lots of gases.
2. the atmosphere was mostly carbon dioxide with basically no oxygen.
3. volcanoes also released nitrogen water vapour methane and ammonia.
what happened in the second phase of the atmosphere?
oceans algae and green plants absorbed carbon dioxide.
1. water vapour in the atmosphere condensed to make oceans.
2. lots of carbon dioxide dissolved into the ocean.
3. green plants and algae absorbed some carbon dioxide to release oxygen.
what happened in the third phase of the atmosphere?
green plants and algae produce oxygen.
1. green plants and algae did photosynthesis and released oxygen.
2. oxygen levels increased allowing complex life to evolve.
3. around 200 million years ago the atmosphere became what it is now.
what is the current atmosphere made of?
80% nitrogen.
20% oxygen.
less than 1% other gases. (such as carbon dioxide noble gases water vapour)
why do greenhouse gases cause the greenhouse effect?
greenhouse gases don’t absorb short wavelengths coming from the sun but they do absorb long wavelengths coming from the earth.
greenhouse gases then release thermal radiation back to earth warming it up.
what human activities affect greenhouse gases in the atmosphere?
deforestation.
burning fossil fuels.
agriculture.
creating waste.
what are the negatives of climate change?
ice caps melting. (rising sea level)
changes in rainfall patterns.
frequency and severity of storms.
changes in temperature.
what is a carbon footprint?
a measure of the amount of carbon dioxide released over the full life cycle of something.
how can a carbon footprint be reduced?
renewable energy sources.
more efficient processes.
tax based on emissions.
a cap on emissions allowed to be released.
carbon capture.
how are gases released from the combustion of fossil fuels?
if there is not enough oxygen incomplete combustion happens.
solid particles and unburnt fuel are released and carbon monoxide and dioxide can be released.
what are the problems with particulates in the air?
they can get stuck in lungs.
they reflect sunlight causing global dimming.
what are the problems with carbon monoxide?
stops blood from carrying oxygen.
has no smell or colour so can’t be detected.
what are the problems with sulfur dioxide and nitrogen oxide?
when mixed with clouds acid rain is formed.
they cause respiratory problems.
