Topic 9: Chemistry of the atmosphere Flashcards
what was earths early atmosphere like?
mostly carbon dioxide with virtually no oxygen
the early earth was mostly covered in?
volcanoes
how did oceans form?
the water vapor condensed to form oceans
why did the carbon dioxide levels go down?
- it was dissolved by the oceans to form carbon precipitates that formed sediments on the seabed
- plants used it for photosynthesis
how is coal formed?
from thick plant deposits
how is limestone formed?
calcium carbonate deposits from shells and skeletons
how is crude oil and natural gas formed?
from plankton
what is the formula for photosynthesis?
carbon dioxide + water –> glucose + oxygen
6CO2 + 6H2O –> C6H12O6 + 6O2
how does the enhanced greenhouse effects work?
the sun emits short wavelength radiation to earth which is not blocked by the earths greenhouse gases however the long wavelength radiation that is reflected back to space is blocked by greenhouse gases
what do humans do that increases greenhouse gases?
- Deforestation: less trees to remove CO2 through photosynthesis
- Burning fossil fuels: carbon is trapped in fossil fuels and is released when they are burned
- Agriculture: farm animals produce methane
- Creating waste: CO2 created by deposition of waste
why is our climate now changing?
because more CO2 is being released
what are the dangers of global warming?
1) ice caps melting: higher sea level causes flooding and more coastal erosion
2) changes in rainfall pattern causes places to get a surplus or reduced amount of rainfall
3) the frequency and severity of storms can increase
4) Changes in temperature and amount of water available in a habitat may affect wild species, leading to differences in their distribution
what are carbon footprints?
a measure of the amount of carbon dioxide and other gases released over the full life cycle of something
how can you reduce your carbon footprint?
- use renewable energy
- using efficient processes to conserve energy and cut waste
- governments could tax CO2 emissions
- there is technology that captures CO2
why is it hard to reduce CO2?
- technologies need to be developed
- hard to make international agreements of CO2
- people need to change their lifestyle