Download Chapter 7.2 Revision Answers

Chapter 7.2 Revision Answers
A
B
B
A/C
D
D
C
D
A
(a)
Award marks for 4 flows and 1 storage as shown on diagram.
Flows must be linked to an arrow in the correct direction and
include both number and process to gain the mark.
5
(b)
3.1 × 109/3 100 000 000/3.1 billion tonnes/3.1 Gigatonnes/3.1 Gt
Powers of ten and units must be correct for credit.
1
(c)
(i)
1
(ii)
Photosynthesis;
Allow as alternatives to “light”: sunlight, solar energy, insolation.
(d)
(i)
(ii)
carbon dioxide is a greenhouse gas/causes the greenhouse effect;
increasing levels of carbon dioxide may cause global warming/
melting of ice caps/rising sea levels/shifting of biomes/
changes in weather patterns/disruption of ocean currents/
increased rates of extinction/reduction in crop yields;
Allow any other reasonable points
some countries co-operate with other nations to agree limits
to global carbon emissions;
e.g. recent ratification of Kyoto Protocol (Treaty) by many
countries;
specific details about which countries have agreed to/rejected
controls on their carbon emissions;
specific details about actions agreed to by specific countries;
e.g. use of carbon or energy taxes;
developed countries assist less developed countries to install
cleaner technology;
trading in carbon credits/exchanges;
Allow other relevant points, provided they relate to
international cooperation
3
2 max
3 max
[15]
(a)
57 % 1
(b)
the increase, or possible future increase in the average temperature of the earth’s
atmosphere as the result of the build up of greenhouse gases (e.g. carbon dioxide,
methane) / OWTTE;
1
(c)
(i)
the impact of global warming on society may be felt on a number of
scales, local, national and international. In addition the impact of global
warming may be direct or indirect. Students should be given credit for
any relevant answer demonstrating a link between global warming and
society. Examples include: drought driven by climate change and social
stress, loss of resources, changing agricultural practice, loss of land,
migration, political change and war;
(ii)
(d)
(e)
sea level change will lead to coastal inundation;
and perhaps coastal erosion;
3 max
2
Four correct [2], two or three correct [1].
afforestation, reducing emissions, reducing fossil fuel burning, reducing heat
emissions, preventing desertification, controlling population;
2
the global environment has experienced significant warming and cooling
episodes over last 20000 years;
even though human industrialization occurred only in the last 200 years;
2
[11]
(a)
a simplified description of reality;
designed to show the structure or workings of an object, system or concept;
2
(b)
oceanic circulation/ice/human activity/land and terrestrial features;
[1] for any two correct.
1
(c)
nitrogen/oxygen/carbon dioxide/water vapour/methane/ozone/
other named trace gases;
Four correct [2], three or two correct [1].
(d)
(e)
(f)
solar inputs will be short wavelength, and radiation outputs will be long
wavelength;
pollutant emissions leading to photochemical smogs;
increased global temperatures through burning fossil fuels;
altering chemistry of precipitation through sulfur dioxide/SO2 and
nitrogen oxide/NOx emissions; x depletion of stratospheric ozone
increasing input of UV light;
reducing rainfall through deforestation;
2
1
3 max
strengths:
it stresses the interactions (feedback) within the system;
represents the complex atmosphere as a system with inputs, outputs
and transfers;
Accept other reasonable strengths.
limitations:
nature of the interactions is not really shown;
some categories are too broad to be helpful e.g. atmospheric circulation;
some interactions are not shown;
relative importance of different parts of the system not shown;
Answer must refer to both strengths and limitations for full marks.
4 max
[13]
(a)
the trend shows temperature with high years and low years with an
overall upward trend;
accelerating in the last quarter of the graph;
temperatures prior to about 1935 were below the average (for 1951–1980);
but from 1980 they were above the average;
2 max
(b)
(c)
the onset of global industrialization;
and the subsequent production of fossil fuel derived pollution;
deforestation, particularly of rainforest;
perhaps volcanic activity;
sunspot activity;
2 max
control the amount of atmospheric pollution;
reduce atmospheric pollution;
stop forest clearance;
increase forest cover;
develop alternative renewable energy sources;
improve public transport;
set national limits on carbon emissions;
carbon dioxide capture;
Accept other reasonable answers.
1 max
(d)
Impact on the Environment
Impact on Society
Impact
Ice and Snow
Ocean and Coast
deglaciation/
glacier retreat;
sea level rise/
coastal flooding;
Impact
Water resources
Food and
Agriculture
may cause
drought;
agriculture
moving north/
south;
Hydrology
Increased flooding
Coastal living
flooding/storms;
Ecosystems
biome shifts/
species change;
Human health
increased disease;
Award [4 max] for seven impacts, [3 max] for five or six impacts,
[2 max] for three or four impacts and [1 max] for one or two impacts.
(e)
LEDC because technologically/economically less able to cope;
greater percentage of population already vulnerable;
weak infrastructure/communications/emergency services;
Accept other reasonable suggestions.
Award [0] for LEDC on own.
2 max
[11]
ESSAY
(a)
Effects due to: increased carbon dioxide levels/sulfur oxides/
nitrogen oxides/unburned hydrocarbons/particulates/lead/
carbon monoxide/mining/pollution of oceans.
Allow up to [2] for more than 3 effects and then up to [2] for each
category.
Candidates are asked to review so there should be an overview of
most effects not emphasis on one or two.
Carbon dioxide increases → global warming → climate change
→ sea levels rise/disruption of ocean currents (e.g. in North
Atlantic)/possible negative feedback effects from increased snow
fall at poles/coral bleaching/ice caps melt/flooding of low-lying
lands/biomes shift/food production changes [2];
sulfur dioxide → acid deposition → Al/cations leaching → tree
death/acidifies lakes/limestone buildings eroding [2];
nitrogen oxides → also acid deposition/photochemical smog/
CFC breakdown/pollution of oceans/effects of transporting
large quantities of oil round the world e.g. oil spillages,
Exxon Valdez (March 1989), oiling of seabirds [2].
Credit up to one specific health effect correctly attributed to fossil
fuel induced pollution e.g. asthma.
(b)
(c)
(Give credit also for review of other impacts.)
8 max
Award marks for up to 5 strategies (e.g. carbon taxes/alternative
sources of energy/energy efficiencies/liming), provided some
relevant detail is given for each example.
5 max
USA uses more [1]/larger and less efficient automobiles [1];
→ more gases released [1]/In North America, petrol is cheaper so
North Americans use more gasoline per capita [1]; ecological
footprint high [1]/new cars – more efficient technology in
newer engines – cleaner emissions [2]/pollution effects lead to
strong campaign for pollution controls [1]/more smog and
other pollution effects (including lead in environment) [1].
4 max
Candidates may approach problem from either European ‘direction’
or North American ‘direction. e.g. expensive petrol in Europe
encourages more use of public transport, leading to less pollution;
cheap petrol in USA makes public transport unattractive and use
of cars more likely, etc. Credit either approach.
Expression of ideas [3 max]
[20]