ATMOSPHERE Flashcards
What did the early atmosphere mostly consist of
carbon dioxide with virtually no oxygen
what built up the atmosphere over time
volcanic activity also released nitrogen as well as water vapour and small amounts of methane and ammonia
how do people think the early atmosphere was formed
that the surface was covered in volcanoes that erupted and released lots of gases
how did oceans form
when the water vapor in the atmosphere condensed it formed oceans
how was carbon dioxide removed from the early atmosphere
lots of carbon dioxide was removed from the early atmosphere as it dissolved in the oceans
green, plants and algae evolved and absorbed some of the carbon dioxide so that they could carry out photosynthesis
when organisms died the carbon they took from the atmosphere gets trapped inside them which reduced the carbon dioxide levels in the early atmosphere
how are sedimentary rocks formed
when plants, plankton and marine animals die they fall to the sea bed and get buried by layers of sediment.
over millions of years they become compressed and form sedimentary rocks
name three fossil fuels
coal
crude oil
natural gas
how is crude oil and natural gas formed
from deposits of plankton
name 2 sedimentary rocks
coal
limestone
how were oxygen levels in the early atmosphere increased
and how did this affect the atmosphere
green plants and algae produced oxygen by photosynthesis plants use light to convert carbon dioxide into sugars and oxygen
as oxygen levels built up over time more complex life (like animals)
name greenhouse gases
carbon dioxide
methane
water vapour
what do these greenhouse gases do
they act as an insulating layer in the earths atmosphere this allows the earth to be warm enough to support life
what human activities are affecting the amount of greenhouse gases in the atmosphere
deforestation- fewer trees means less co2 is removed from the atmosphere by photosynthesis
burning fossil fuels- carbon that was locked up in the fuels is released as co2
agriculture- more farm animals produce more methane through their digestive processes
creating waste- more co2 and methane released from the decomposition of waste
why do scientist think that the earths temperature is increasing
they think that the extra carbon dioxide from human activity is causing this increase and that this will lead to climate change
consequences of climate change
as temperature increases this could lead to polar ice caps melting which causes a rise in sea levels, increased flooding in coastal areas and coastal erosion
changes in temperature and the amount of water available in a habitat may affect wild species, leading to differences in their distribution
the frequency and severity of storms may also increase
what are carbon footprints
a measure of the amount of carbon dioxide and other greenhouse gases released over the full life cycle of something.
how do you reduce your carbon footprint
renewable energy sources or nuclear energy instead of fossil fuels
using more efficient processes could conserve energy and cut waste
goverments can tax companies or individuals based on the amount of greenhouse gases they emit
goverments can also put a cap on emissions of all greenhouse gases that companies make
why is making reductions to your carbon footprint still difficult
a lot of governments are worried that making these changes will impact on the economic growth of communities
a lot of countries don’t want to sacrifice their economic development if they think others wont do the same
air pollution from incomplete combustion
as fossil fuels contain hydrocarbons during combustion the carbon and the hydrogen in these compounds are oxidised all of the fuel burns if there is plenty of oxygen
if there isn’t enough oxygen incomplete combustion takes place and particulates and unburnt fuel are released and carbon monoxide can be produced as well as carbon dioxide
problems air pollution can cause
if particulates are inhaled they can get stuck in the lungs and cause damage which can lead to respiratory problems
particulates can also cause global dimming
carbon monoxide can stop your blood from carrying oxygen around your body this lack of oxygen can lead to fainting, a coma or even death
carbon monoxide doesn’t have any colour or smell so its hard to detect.
what is released during the complete combustion of hydrocarbons/fossil fuels
carbon dioxide and water vapour, sulfur dioxide
acid rain
Sulfur dioxide is caused when sulfur atoms which are present in some fossil fuels are oxidised:
Sulfur dioxide is then further oxidised in the atmosphere to sulfur trioxide, SO3. This gas dissolves in rainwater to make acid rain,
problems with acid rain
acid rain kills plants and damages builidngs and statues
name three potential pollutants that could be released as a result of incomplete combustion of hydrocarbons that wouldn’t be released as a result of complete combustion
particulates (soot)
unburnt fuels
carbon monoxide
what are particulates
soot
how are particulates produced
Incomplete combustion of any fuel containing carbon atoms
how is carbon monoxide produced
Incomplete combustion of any fuel containing carbon atoms
how is sulfur dioxide produced
Combustion of a fossil fuel which contains sulfur impurities
how are nitrogen oxides formed
Oxidation of atmospheric nitrogen inside the engine of a car, lorry, etc
explain how the greenhouse affect works to keep the earth warm
greenhouse gases don’t absorb the incoming short wavelength radiation from the sun but they do absorb the long wavelength radiation that gets reflected back off the earth
then they re radiate it in all directions including back towards the earth
this longwave radiation is thermal radiation so it results in warming the surface of the earth.
how is carbon dioxide produced
Complete combustion of any fuel containing carbon atoms
