The atmosphere Flashcards
name the gases in the atmosphere today
Nitrogen
Oxygen
other gases
(co2, water vapour, noble gases)
state the proportions of each gas - approximately
Nitrogen - 80%
Oxygen- 20%
other gases- small proportions
(co2, water vapour, noble gases)
name a noble gas present in the atmosphere
argon
how long has the gases in the atmosphere remained the same for
200 million years
how old is the earth
4600 million
the earth is very old. how does this affect theories about the early atmosphere
scientists cannot be certain about the early atmosphere
Theories about Earth’s early atmosphere and how it formed changed and developed
what happened during the first billion years
during first billion years of the Earth’s
existence there was intense volcanic activity
what did the volcanoes release
released other gases that formed the early atmosphere eg
water vapour
(large amount of CO2)
(smaller amount of nitrogren)
(tiny bit of methane and ammonia)
how were oceans formed
as earth cooled, water vapour (from volcano), condensed to form oceans
what did the early earths atmosphere consist of
mainly CO2
little/ no O2
what can you compare the earths early atmosphere to
mars + venus today
what can you say about nitrogen in the early atmosphere
2 points
. Volcanoes also produced nitrogen
. gradually built up in the atmosphere
describe the early atmosphere
mainly CO2
small but increasing amounts of nitrogen
differences between early atmosphere and the present one
much more nitrogen now (80%)
much less CO2 now
much more O2 now (21%)
how was the CO2 percentage decreased
some Co2 dissolved in ocean to form a weak acid
this reacted with minerals in the sea
Co2 preciptates are formed in the ocean
over time this formed sediments of carbonate rocks on the sea bed
what was some co2 in the sea used to create
corals and shells of organisms
how did O2 increase in the atmosphere . how did thisaffect CO2
algae and plants evolved,
they photosynthesised,
releasing O2 and taking in CO2
what happened 2.7 billion years ago
algae first produced oxygen
what happened a billion years after algae first produced oxygen
plants evolved and the % of oxygen increased- allowing animals to evolve
two ways CO2 % decreased
.by formation of sedimentary rocks and fossil fuels that contain carbon
.Plants photosynthesise
what is coal made from
from remains of ferns and trees
that haven’t decompose
how is coal formed
plant remains covered with sediment + compressed
high temp + pressure creates coal
what and how is oil formed
remains of dead biomass , plankton, under the sea bed, compressed by sediment.
heat + pressure convert it to crude oil
what is natural gas
mainly hydrocarbon methane
where is natural gas found
near deposits of oil
how is natural gas formed
from plankton in a similiar way to oil
what do all fossil fuels contain, and where did this come from
carbon.
came from CO2 taken in by photosynthesis
3 green house gases found in the atmosphere
water vapour
carbon dioxide
methane
Describe process wherein radiation gets trapped in atmosphere
.energy from sun travels to earth ( Short WL radiation)
.some reflected back into space
.most passes into atmosphere
.energy from radiation absorbed at earths surface
.earths surface radiates energy as (Long WL radiations)
.some Long WL radiation interferes with greenhouse gas molecules in atmosphere
.the energy in the Long WL radiation is absorbed / trapped
why does most of the sun energy pass easily into the earths atmosphere
because the sun energy is short wavelength radiation-
which does not react much with gas in atmosphere
2 examples of short wave radiation
ultraviolet
visible light
example of long wave radiation
infra red
why does the temp of atmosphere increase
because energy (Long WL radiation) is trapped in the atmosphere
how is the greenhouse effect helpful
keeps the temp on earth warm enough to support life.
(without it, too cold for most organisms to survive)
what are the two main gases in the atmosphere
how much of each
nitrogen 20
oxygen 80
2 human activities that increase CO2
as we burn fossil fuels
as we cut down trees- deforestation
what are
coal,
petrol, diesel
gas
burned for
coal, -electricity
petrol,diesel,- power cars
gas- heat homes
how and why is deforestation happening
forests burned
for more land to graze cattle
what are the two ways deforestation increases CO2 %
burning trees releases CO2
less trees to photosynthesise = less CO2 being taken in + less O2 out
what human activities release more methane into atmosphere
released in agriculture eg growing rice in flooded paddy fields
when cattle - cows- pass wind
what 4 human activities increase greenhouse gases in the atmosphere
agriculture, growing rice in flooded fields
cattle
deforestation
burning fossil fuels
how does increased greenhouse gases increase temp
temp rises as more of the energy from the sun is trapped
How can climate change lead to floods
increase melting of polar ice sheets/ glaciers
increases sea levels
could mean flooding of low lying areas
what will climate change do to weather
more severe weather eg storms in uk
how can climate change effect animals and disease
increasing temp change distribution of:
animals eg insects
+
insect borne disease eg malaria
4 affects of climate change
increased floods
severe weather
change in distribution of
animals
insect borne disease
what do many scientists believe about the cause of climate change
it is due to human activities that release greenhouse gases and thus increase the earths temp
Based on …… …….evidence, many scientists believe that
….. activities will cause the temperature of the Earth’s
atmosphere to …….. at the …….and that this will result in
…… climate change.
what type of evidence do scientists use when it comes to climate change.
peer reviewed evidence
why is peer review process important
detect false claims based on poor evidence/bias
what is peer reviewed evidence
when scientists can criticise the evidence and decide if its valid
problem with our understanding of climate change
climate change is complex and difficult to model
climate change is complex and difficult to model- what 3 things does this lead to
-simplified models of climate change
-speculation - based only on parts of evidence - biased
-biased media stories - opinions
it is difficult to model such complex systems as global
climate change. This leads to simplified models, speculation and
opinions presented in the media that may be based on only parts of
the evidence and which may be biased.
what do scientists have to do due to this
scientists have to
work harder to communicate ideas to public
example of an uncertainty about climate change
don’t know exact amount temp of atmosphere will increase
what can uncertainty about climate change lead to
speculation in the media
define carbon foot print.
LEARN the definition
The carbon footprint is the total amount of cO2 + other
greenhouse gases emitted over the full life cycle of a product,
service or event.
3 ways we can reduce carbon dioxide emissions
insulating homes/ turning down heating
renewable power sources
public transport instead of cars
where is the energy for heating homes from
from burning fossil fuels
why is public transport more environmentally friendly
releases less CO2 per passenger
why is it better to use renewable sources of electricity
renewable sources of electricity don’t burn fossil fuels- release CO2
how can we save electricity on a personal level
energy saving lightbulbs
turn appliances off at the plug
why may actions to reduce greenhouse gas emmisions and to save energy be limited
most of the solutions are expensive
+
inconvenient
what is the biggest source of methane
agriculture
how can we reduce methane emmisions( in agriculture)
eat less beef + dairy products
as grazing cattle ( their farts ) release methane
why are actions to reduce methane emmissions limited
people like beef and dairy producrs, so wont eat less
trapping + burning methane for electricity costs money
two sources of methane
landfills
grazing cattle
how can we reduce methane emmitted from landfills
by trapping the methane
Burning it
to produce electricity
why is it a good idea to trap methane from landfills and burn it for electricity
methane more powerful greenhouse gas then carbon dioxide
what is a negative to trapping and burning methane
it costs money
2 ways to reduce Methane emissions
eat less beef/ dairy products
trap + burn methane to make electricity
what do fuels do
release energy when combusted (burnt)
2 examples of fuels
coals and hydrocarbons
what is coal often used for
to generate electricity in power stations
what are hydrocarbons, like those in petrol and diesel, used for
to power vehicles
what elements do most fuels contain
carbon and hydrogen
potentially some sulfur
what happens when we burn most fuels
carbon and hydrogen elements are oxidised
-the atoms react with oxygen in the air
where is methane found
what is it used for
found in natural gas
used to heat homes
write balanced equation for complete combustion of methane
CH(4) + 2O(2) = CO(2) + 2H(2)O
what is made from complete combustion of methane
co2 and H2O
why does burning fuels contribute to climate change
because the complete combustion (burning) of fuels releases carbon dioxide, a greenhouse gas
what happens when methane is burned with reduced oxygen
carbon monoxide is produced
(instead of carbon dioxide)
what is carbon monoxide
a toxic gas
describe carbon monoxide gas
what do people have to tackle this
colourless
no smell
people have carbon monoxide detectors in homes
what are the three products of combustion
carbon dioxide,
carbon monoxide
water vaour
how can you tell that a reaction is complete combustion and not incomplete
carbon dioxide is formed in complete
coal contains sulfur
what happens when coal is burned
the sulfur atoms are oxidised
what is produced from combustion of coal
sulfur dioxide
where are oxides of nitrogen produced
inside engines eg cars
why / how are oxides of nitrogen produced in engines
the high temperatures cause nitrogen and oxygen from the air to react
what 2 affects does sulfur dioxide and oxides of nitrogen cause
breathing problems
dissolve in rain water- form acid rain
what does acid rain do
damage trees
corrode buildings made of limestone
how are particulates formed
from burning fuels eg diesel
what are particulates
particles of carbon
+
unburned hydrocarbons
what is soot
particles of carbon
what is the affect of particulates on human health
increase risk of heart disease
increase risk of lung disease
what 2 broad affects do particulates have
affect health
global dimming
how do particulates cause global dimming
they reduce amount of sun energy that reaches earths surface
what does global dimming affect
rainfall patterns
In coal, why are the dead plants and organisms not decomposed
due to a lack of O2 / acidic condition
