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Date May 2019 Marks available 4 Reference code 19M.2.SL.TZ0.6
Level Standard Level Paper Paper 2 Time zone Time zone 0
Command term Identify Question number 6 Adapted from N/A

Question

Identify four strategies for limiting the impact of burning fossil fuels without reducing their use.

[4]
a.

Suggest a range of practical procedures that could be carried out to measure the abiotic and biotic impacts of an oil spill in an aquatic ecosystem.

[7]
b.

Even though there is growing global support for ecocentric values, the global consumption of fossil fuels continues to rise each year.

With reference to energy choices in named countries, discuss possible reasons for this situation occurring.

[9]
c.

Markscheme

use of scrubbers on factories/power plants;
use of catalytic converters on vehicles;
regulating quality of exhaust gases;
using low sulphur coal resources;
restoring ecosystems damaged by pollutants / eg liming of acidified lakes;
sequestration/CCS;
afforestation/reforestation/reducing deforestation;
masks reducing inhalation of toxic gases/emissions;
building of sea defences;
vaccination/anti-malarial programmes;

Credit any responses identifying other valid strategies that don’t involve reducing fossil fuel use. Do not credit “increasing efficiency of vehicles/machinery using fossil fuels” ...these will only limit impact by reducing consumption, which is explicitly excluded by question.

[4 max]

a.

identify a transect / sampling scheme to compare conditions over time/distance;
carry out multiple samples at each site to ensure reliability;
measure oil content/concentration using chemical tests;
measure light penetration using Secchi disc;
(use appropriate probes/meters/logging devices) to measure temperature/oxygen concentration/pH/salinity;
measure change in O2 concentration of samples kept in dark as a measure of BOD;
sample invertebrate populations using kick samples/Eckman grab/water samples;
Lincoln Index/mark-release-recapture may be used to quantify fish/larger invertebrates;
identify species present and abundance of each;
use this to calculate a biotic index evaluating sensitivity/tolerance of species present;
use similar data to calculate diversity with a diversity index;
count total numbers of birds/fish etc clearly impacted/killed by oil;

Credit any other procedures of equivalent detail and validity to those given above.
No additional credit for evaluating procedures/discussing impacts.

If response simply indicates measuring a named abiotic factor they can be credited for MP5 but can only gain one mark in total for any number of such factors. To gain further credit for other abiotic factors they should indicate some detail of the procedure beyond simple use of a probe/meter/logging device.

Award [4 max] for responses that address only biotic or only abiotic impacts.

[7 max]

b.

The following guide for using the markbands suggests certain features that may be offered in responses. The five headings coincide with the criteria given in each of the markbands (although “ESS terminology” has been conflated with “Understanding concepts”). This guide simply provides some possible inclusions and should not be seen as requisite or comprehensive. It outlines the kind of elements to look for when deciding on the appropriate markband and the specific mark within that band.

Answers may include:

[9 max]

Refer to paper 2 markbands, available under the "your tests" tab > supplemental materials.

c.

Examiners report

Many candidates were able to identify appropriate strategies to reduce impacts without reducing the use of fossil fuels although these were often mixed with inappropriate strategies that did imply reduced use of the fuels.

a.

Responses often failed to score well because they just listed factors that could be measured or described how they might be affected, but gave minimal or no practical details of how they could be measured.

b.

Many candidates approached this question well, discussing difficulties with alternative fuels and economic and political pressures for the continued use of fossil fuels. Weaker responses had few relevant and specific examples and a limited range of different reasons for the paradox.

c.

Syllabus sections

Topic 7: Climate change and energy production » 7.3 Climate change—mitigation and adaptation
Topic 7: Climate change and energy production

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