The impacts of climate change — Paper 2 · A Level Environmental Management (AS only) 8291

1 (a) Fig. 1.1 is a diagram representing some of the flows and stores of the hydrological cycle. vapour transport 40 precipitation 111 precipitation 71 385 evaporation run-off 425 evaporation infiltration lake river ocean groundwater flow values are in hundred thousand km3 Fig. 1.1 (i) State what is meant by the terms run-off and infiltration. run-off … … infiltration … … [2] (ii) Use Fig. 1.1 to explain why more water evaporates from the ocean than returns to the ocean as precipitation. … … … … … … … … [4] (iii) Describe one process, other than evaporation, in which water changes state in the hydrological cycle. … … … … [2] (b) Fig. 1.2 shows changes in past global sea-levels and predicted global sea-levels. The predicted global sea-levels are based upon climate change models produced in 2000. 1.4 1.4 past predicted 1.2 1.2 1.0 1.0 0.8 0.8 change in change in 0.6 0.6 global global sea-level sea-level 0.4 0.4 / m / m 0.2 0.2 0.0 0.0 –0.2 –0.2 –0.4 –0.4 250 500 750 1000 1250 1500 1750 2000 2000 2050 2100 year year Key range of values mean value Fig. 1.2 (i) With reference to Fig. 1.2, describe the changes in global sea-levels in the years before 2000. … … … … [2] (ii) Suggest reasons why data before 1870 has a range of values for the change in global sea-level. … … … … [2] Fig. 1.3 shows the area of Bangladesh that would be affected by a long-term rise in global sea-level. N Rangpur Bogra Sylhet Mymensingh Rajshahi Kushtia Dhaka Comilla Jessore Khulna Chittagong Bay of Bengal Cox’s Bazar Indian Ocean Key 0 40 80 120 160 very densely populated area km densely populated area less densely populated area water other land rivers area inundated by a 1 metre sea-level rise area inundated by a 0.5 metre sea-level rise settlement Fig. 1.3 (iii) Suggest the likely effects of a long-term rise in global sea-level on the environment and people of Bangladesh by the year 2100. Refer to Fig. 1.2 and Fig. 1.3 in your answer. … … … … … … … … … … … … … … … … [8] [Total: 20]

20 marks

Mark scheme: 1(a)(i) run-off: water (from precipitation falling on the land) flows across the land surface (to the oceans); infiltration: water is absorbed into the ground / water moves downwards through the soil spaces / permeable layer; 2 1(a)(ii) example explanations: water vapour rises, cools and condenses into clouds, some clouds are carried over the land, therefore some of this occurs as precipitation over the land; some water from the land returns to ocean as run-off and groundwater flow to evaporate over the ocean; retained in atmosphere / the atmosphere is a water store; use of information from Fig. 1.1, e.g. use of data: 425 (hundred thousand cubic kilometres) evaporate over the ocean, only 385 precipitation over ocean, the difference (425–385 = 40) / 40 is carried over land as water vapour, this falls as precipitation over the land; of the 111 (hundred thousand cubic kilometres) of precipitation over the land, only 71 is from evaporation over the land; the difference of 40 (hundred thousand cubic kilometres) between values for precipitation over land and evaporation over land (111–71 = 40) returns to ocean as groundwater flow and surface run-off; 4 Question Answer Marks 1(a)(iii) One mark for a named process. Two marks for a named process and description of the change in state or transfer from store to store. process: melting / transpiration / freezing / condensation; e.g. melting: water changes from (solid) ice / snow to (liquid) water / e.g. glacier to surface run-off; e.g. transpiration: water changes from (liquid) water to (gas) vapour / water from the soil is transported to the leaves, at the leaf surface the water evaporates and vapour diffuses into the atmosphere from the plant store / vegetation to atmosphere; e.g. freezing: water changes from (liquid) water to (solid) ice / snow / e.g. water to frozen lake; e.g. condensation: water changes from (gas) vapour in the air to (liquid) water in clouds / atmospheric water vapour to precipitation; 2 1(b)(i) overall pattern shows increases and decreases; use of data from graph to support, e.g. the range from the highest in approx. 1200 to lowest sea-level in 1750 is 0.48 m; reference to oscillations within the overall pattern; 2 1(b)(ii) sea-levels before 1870 are based upon estimates using qualitative evidence / different models / different people (making estimates); from e.g. geological observations / ice core analysis; (quantitative) data was not recorded / less likely to be recorded; technology / equipment is now more accurate / technology is now more available / recorded now using, e.g. instrumental records / tide gauges / satellites; 2 Question Answer Marks 1(b)(iii) Use of data from Fig. 1.2 and Fig. 1.3 as well as reference to both people and the environment required for full marks. Max. six marks if no reference to either figure. An effect can be developed for an additional mark. Examples may include: environment, e.g.: inundation of land by sea water; low-lying land will be permanently flooded; salinisation of soil; salinisation of freshwater aquifers; increasing salinity of river water; effect on freshwater ecosystems; erosion; people, e.g.: reduction in land area available for population / displacement of settlements / re-location of settlements; reduction in land area available for agriculture / crops; effect on freshwater supply for domestic consumption; effect on freshwater supply for irrigation / crop productivity; effect on freshwater fisheries; effect on wetlands / wetland flooding; use of Fig. 1.3, e.g.: estimation of (approximately 10%) of land will be permanently flooded if the sea-level rise is 0.5 m; proximity to already densely populated region; estimation of (approximately 15%) of land will be permanently flooded if the sea-level rise is 1 m; includes an area that is already densely populated and close in proximity to areas very densely populated, e.g. Dhaka, Khulna; 8 Question Answer Marks 1(b)(iii) use of Fig. 1.2, e.g. ref. to range i.e. estimated sea-level rise could be more or less than 0.5 / 1 metre(s) based on the range of outcomes and have a greater or lesser effect on the area of Bangladesh; these are only models and outcome may be different to this prediction; possibility that sea-level rise is as much as 1.4 metres; Accept other valid effects.

This question in 8291/21 May/June 2017

2 Fig. 2.1 contains information about the Mekong river basin in Southeast Asia and the sites of some dam-building projects. CHINA Snow and glacier melt is the main source of VIETNAM freshwater in the upper course of the river.MYANMAR Hanoi Gulf of Tonkin LAOS The river flow is influenced by the monsoon rains (May to October). Vientiane THAILAND Bangkok CAMBODIA Phnom Penh The Mekong delta: Gulf of Thailand VIETNAM • is an area of low land where the Mekong river splits into smaller rivers • is inundated by saltwater Mekong delta when river flow is low during the dry season (November to April) South China Sea • is a major rice-growing N region of the world • has a population of 0 200 km approximately 17 million. Key capital city agriculture Mekong river basin boundary forested area Mekong river land outside Mekong river basin dam-building projects sea national boundary lake Fig. 2.1 (a) (i) With reference to the information in Fig. 2.1, explain why the Mekong delta is prone to flooding. … … … … … … … … [4] (ii) Explain how global warming could impact on the environment and on the population in areas such as the Mekong delta. … … … … … … … … … … … … [6] (b) (i) Outline two benefits of dam-building projects, such as those shown in Fig. 2.1. … … … … … … … … [4] (ii) Suggest the negative impacts of constructing dams on the Mekong river. Refer to Fig. 2.1 in your answer. … … … … … … … … … … … … [6] [Total: 20]

20 marks

Mark scheme: 2(a)(i) a low-lying area / close to sea level; glacier melt (coincides with); monsoon rainfall / increased precipitation in wet season; increased input of water / river flow / volume / discharge; increase surface run-off; from higher land; reduce infiltration of soil; soil saturation; high water table; less interception in agricultural land due to reduced forest cover; 4 Question Answer Marks 2(a)(ii) environment: increase in temperature; increased melting of glaciers; increased river flow into delta; thermal expansion of sea water; rise in sea level; increased inundation of delta/increased tidal surge; long-term flooding of delta region; salt water intrusion; reduced freshwater stores in river, lake, wetland; salinization of soil; change in hydrological cycle; e.g. increase in storm / frequency / intensity; increased length of dry season; population: effect drinking water supply; effect on rain-fed irrigation; effect on the suitability of land for growing crops; effect on agricultural output of delta; loss of livelihood; migration of population inland; ecological effects; 6 Question Answer Marks 2(b)(i) reservoir stores water during heavy rain / water from glacier melt; for drinking water / domestic use; use in industry; provides a water supply during the dry season; irrigation water for agriculture; extends the growing season ; hydroelectric power generation; electricity supply for cities, e.g. Vientiane; flood protection; control of river flow to lower course of river reducing frequency of downstream flooding; economic value of dams; tourism opportunities; employment opportunities provided by dam building projects; recreation activities; e.g. sailing, fishing; 4 Question Answer Marks 2(b)(ii) effect on the natural flow of water, rate of flow; reduced flow of water to lower course of river; transport of sediments downstream is effected by the build-up of sediment in the dam; reduced supply of nutrients downstream/ reduces soil fertility of farmland in the lower course of the river; effect on agricultural activity; reduced supply of water for rain-fed irrigation; e.g. rice–growing in Mekong Delta; lowering of water table; destruction of wetlands; ecological disruption / effect on freshwater species; effect on freshwater lakes; e.g. reduced supply of water to (Tonle Sap) lake; effect on freshwater fisheries; loss of livelihood for people dependent on the fisheries; increased salinization of delta region; effect on ecosystems destroyed by dam-building; deforestation; dust and noise during dam building; forced displacement of people evicted from their lands and homes; 6

This question in 8291/21 May/June 2018

5 Fig. 5.1 shows a diagram of a cross-section through an island of Tuvalu in the Pacific Ocean. island vegetation coconut trees lagoon crops ocean fresh ground water zone permeable permeable sediment sediment transition zone Key movement of fresh water permeable rock salt ground water zone movement of transition zone during the year Fig. 5.1 (a) Describe and explain the impact of rising sea levels on islands such as the one shown in Fig. 5.1. [10] (b) Describe the impact of global warming on global water stores. Using examples, discuss how successfully countries can manage changing water stores. [30] [Total: 40]

40 marks

Mark scheme: 5(a) Impacts resulting from a rise in sea level include: inundation of sea water, increased tidal surges, the increased flooding of low-lying land and salt water intrusion. This results in the destruction of shoreline vegetation, a diminishing availability of freshwater and the increased salinisation of soil, changes in the suitability of the land for growing crops and a change in the water cycle. There is a reduction in land available for habitation and the cultivation of crops, leading to a loss of livelihood and the threat of evacuation of an island population. A rise in the water table and transition zone and a decrease of the freshwater zone in Fig.5.1 should be described. Please use level descriptors 1 10 5(b) The question requirements are: • to describe the impact of climate change/global warming on global water stores • to discuss the management of changing water resources • to use examples Indicative content: The impact on water stores include: an increased volume of saltwater stores in seas and oceans; decreased volumes of freshwater stores in glaciers and ice caps; changes in precipitation and atmospheric moisture; changes in river, freshwater lake, and soil moisture levels, and an effect on vegetation stores. Examples of methods of adapting to changing water stores include, for example, adaptation planning, capturing rainwater, the use of desalination plants, water conservation and water rationing measures or changes in agricultural practice, for example, the growing of salt-tolerant crops and drought resistant crops. Please use level descriptors 2 30 Section B descriptor levels: Descriptor Award Mark Consistently meets the level criteria Mark at top of level Meets the criteria, but with some inconsistency Middle, mark to just below top mark Meets most of level criteria, but not all convincingly Just below middle, mark to just above bottom mark On the borderline of this level and the one below Mark at bottom of level level descriptors 1 Level one, 8–10 marks The response: • contains few errors • shows a very good understanding of the question • shows a good use of data or the information provided, where appropriate • provides a balanced answer Level two, 5–7 marks The response: • may contain some errors • shows an adequate understanding of the question • shows some use of data or the information provided, where appropriate • may lack balance Level three, 1–4 marks The response: • may contain errors • shows limited understanding of the question • shows little or no use of data or the information, where appropriate • lacks balance Section B descriptor levels: level descriptors 2 Responses: Level one, 25–30 marks • fulfil all the requirements of the question • contain a very good understanding of the content required • contain a very good balance of content • contain substantial critical and supportive evaluations • make accurate use of relevant vocabulary Level two, 19–24 marks • fulfil most of the requirements of the question • contain a good understanding of the content required • contain a good balance of content • contain some critical and supportive evaluations • make good use of relevant vocabulary Level three, 13–18 marks • fulfil some requirements of the question • contain some understanding of the content required • may contain some limited balance of content • may contain brief evaluations • make some use of relevant vocabulary Level four, 6–12 marks • fulfil limited requirements of the question • contain limited understanding of the content required • may contain a poor balance of content • may not contain evaluations • make limited use of relevant vocabulary Section B descriptor levels: Level five, 1–5 marks • fulfil a few requirements of the question • contain a very limited understanding of the content required • are likely to be unbalanced and undeveloped • evaluative statements are likely to be missing • make no use of relevant vocabulary

This question in 8291/22 May/June 2018

5 Fig. 5.1 shows a diagram of a cross-section through an island of Tuvalu in the Pacific Ocean. island vegetation coconut trees lagoon crops ocean fresh ground water zone permeable permeable sediment sediment transition zone Key movement of fresh water permeable rock salt ground water zone movement of transition zone during the year Fig. 5.1 (a) Describe and explain the impact of rising sea levels on islands such as the one shown in Fig. 5.1. [10] (b) Describe the impact of global warming on global water stores. Using examples, discuss how successfully countries can manage changing water stores. [30] [Total: 40]

40 marks

Mark scheme: 5(a) Impacts resulting from a rise in sea level include: inundation of sea water, increased tidal surges, the increased flooding of low-lying land and salt water intrusion. This results in the destruction of shoreline vegetation, a diminishing availability of freshwater and the increased salinisation of soil, changes in the suitability of the land for growing crops and a change in the water cycle. There is a reduction in land available for habitation and the cultivation of crops, leading to a loss of livelihood and the threat of evacuation of an island population. A rise in the water table and transition zone and a decrease of the freshwater zone in Fig.5.1 should be described. Please use level descriptors 1 10 5(b) The question requirements are: • to describe the impact of climate change/global warming on global water stores • to discuss the management of changing water resources • to use examples Indicative content: The impact on water stores include: an increased volume of saltwater stores in seas and oceans; decreased volumes of freshwater stores in glaciers and ice caps; changes in precipitation and atmospheric moisture; changes in river, freshwater lake, and soil moisture levels, and an effect on vegetation stores. Examples of methods of adapting to changing water stores include, for example, adaptation planning, capturing rainwater, the use of desalination plants, water conservation and water rationing measures or changes in agricultural practice, for example, the growing of salt-tolerant crops and drought resistant crops. Please use level descriptors 2 30 Section B descriptor levels: Descriptor Award Mark Consistently meets the level criteria Mark at top of level Meets the criteria, but with some inconsistency Middle, mark to just below top mark Meets most of level criteria, but not all convincingly Just below middle, mark to just above bottom mark On the borderline of this level and the one below Mark at bottom of level level descriptors 1 Level one, 8–10 marks The response: • contains few errors • shows a very good understanding of the question • shows a good use of data or the information provided, where appropriate • provides a balanced answer Level two, 5–7 marks The response: • may contain some errors • shows an adequate understanding of the question • shows some use of data or the information provided, where appropriate • may lack balance Level three, 1–4 marks The response: • may contain errors • shows limited understanding of the question • shows little or no use of data or the information, where appropriate • lacks balance Section B descriptor levels: level descriptors 2 Responses: Level one, 25–30 marks • fulfil all the requirements of the question • contain a very good understanding of the content required • contain a very good balance of content • contain substantial critical and supportive evaluations • make accurate use of relevant vocabulary Level two, 19–24 marks • fulfil most of the requirements of the question • contain a good understanding of the content required • contain a good balance of content • contain some critical and supportive evaluations • make good use of relevant vocabulary Level three, 13–18 marks • fulfil some requirements of the question • contain some understanding of the content required • may contain some limited balance of content • may contain brief evaluations • make some use of relevant vocabulary Level four, 6–12 marks • fulfil limited requirements of the question • contain limited understanding of the content required • may contain a poor balance of content • may not contain evaluations • make limited use of relevant vocabulary Section B descriptor levels: Level five, 1–5 marks • fulfil a few requirements of the question • contain a very limited understanding of the content required • are likely to be unbalanced and undeveloped • evaluative statements are likely to be missing • make no use of relevant vocabulary

This question in 8291/23 May/June 2018

4 Lake Chad is a large lake in northern central Africa that provides fresh water to around 30 million people in the countries of Chad, Cameroon, Niger and Nigeria. In 1963, Lake Chad covered an area of approximately 25 000 square kilometres. Fig. 4.1 shows changes to the area of Lake Chad from 1963 to 2007. Lake 1963 1973 1987 Chad N N N Chad Chad Chad Niger Niger Niger Nigeria Nigeria Nigeria Cameroon Cameroon Cameroon 1997 2007 Key N N Chad Chad water Niger Niger area of lake in 1963 vegetation country boundaries Nigeria Nigeria Cameroon Cameroon Fig. 4.1 (a) Describe the change in Lake Chad shown in Fig. 4.1 and suggest the effects of this change on the human population living around Lake Chad. [10] (b) Outline factors which may cause diminishing water supplies. Using examples, assess strategies to manage the conservation of natural water resources. [30] [Total: 40]

40 marks

Mark scheme: 4(a) Lake Chad has shrunk dramatically in size, with the rate of loss accelerating. The loss of water has been from the north and east. Human population relies on the lake for water to support and irrigate crops, for drinking water for animals and themselves, and for fishing (both for food and as a living). Loss of water has also led to increasing desertification in the area. Please use level descriptors 1 10 4(b) The question requirements are: • To outline factors which lead to the reduction of water supplies and stores • To describe how the loss of water changes the ecosystem and affects the lives of the people • To suggest strategies to manage the conservation of such water resources. Causes include loss of flow in rivers due to dams which also increase silting, increase in human population leads to increased use of water for irrigation, water for livestock and human drinking water. The change in weather patterns such as monsoon rains which recharge the lake failing leading to drought conditions. Deforestation, over-extraction from aquifers, pollution including global warming leading to loss of ice stores. Strategies to include seeking international cooperation for the diversion of rivers to refill lakes, encourage HEP dams to release water in regular flows, improve dredging processes to prevent silt build up, build efficient irrigation systems for farms to reduce waste, education of the population in water conservation e.g. grey water/recycling water, rain-water collection, desalinisation. Please use level descriptors 2 30

This question in 8291/22 May/June 2019

4 Lake Chad is a large lake in northern central Africa that provides fresh water to around 30 million people in the countries of Chad, Cameroon, Niger and Nigeria. In 1963, Lake Chad covered an area of approximately 25 000 square kilometres. Fig. 4.1 shows changes to the area of Lake Chad from 1963 to 2007. Lake 1963 1973 1987 Chad N N N Chad Chad Chad Niger Niger Niger Nigeria Nigeria Nigeria Cameroon Cameroon Cameroon 1997 2007 Key N N Chad Chad water Niger Niger area of lake in 1963 vegetation country boundaries Nigeria Nigeria Cameroon Cameroon Fig. 4.1 (a) Describe the change in Lake Chad shown in Fig. 4.1 and suggest the effects of this change on the human population living around Lake Chad. [10] (b) Outline factors which may cause diminishing water supplies. Using examples, assess strategies to manage the conservation of natural water resources. [30] [Total: 40]

40 marks

Mark scheme: 4(a) Lake Chad has shrunk dramatically in size, with the rate of loss accelerating. The loss of water has been from the north and east. Human population relies on the lake for water to support and irrigate crops, for drinking water for animals and themselves, and for fishing (both for food and as a living). Loss of water has also led to increasing desertification in the area. Please use level descriptors 1 10 4(b) The question requirements are: • To outline factors which lead to the reduction of water supplies and stores • To describe how the loss of water changes the ecosystem and affects the lives of the people • To suggest strategies to manage the conservation of such water resources. Causes include loss of flow in rivers due to dams which also increase silting, increase in human population leads to increased use of water for irrigation, water for livestock and human drinking water. The change in weather patterns such as monsoon rains which recharge the lake failing leading to drought conditions. Deforestation, over-extraction from aquifers, pollution including global warming leading to loss of ice stores. Strategies to include seeking international cooperation for the diversion of rivers to refill lakes, encourage HEP dams to release water in regular flows, improve dredging processes to prevent silt build up, build efficient irrigation systems for farms to reduce waste, education of the population in water conservation e.g. grey water/recycling water, rain-water collection, desalinisation. Please use level descriptors 2 30

This question in 8291/23 May/June 2019

3 Fig. 3.1 is an extract from an article. Arctic sea ice at minimum extent 06/12/2016 Scientists at the National Snow and Ice Data Centre (NSIDC) said that there was a reduction in the extent of Arctic sea ice for a short time in November, calling this an ‘almost unprecedented’ event. Sea ice decreased by around 50,000 km2 in this period, mainly in the Barents Sea. This removed an area of ice larger than Denmark from the Arctic at a time of year when sea ice is usually increasing. Fig. 3.1 (a) Describe the possible causes and effects of the change in the extent of the sea ice outlined in Fig. 3.1. [10] (b) Assess the success of international protocols, such as Kyoto, in managing the biosphere. [30] [Total: 40]

40 marks

Mark scheme: 3(a) Causes Increased release of greenhouse gases such as carbon dioxide and methane lead to increased global temperature, which causes the arctic temperature to rise and thus reduces sea ice formation. The loss of ice reduces the albedo effect so more absorption increases sea temperature and increases the effect. Increased soot deposition also has a similar effect. As the volume of ice decreases ocean currents and climate are affected hastening the changes. Effects Reduction in volume and thickness of ice as well as the area of ocean covered by ice. Loss and change of habitat affecting species, e.g. polar bears. Spread of diseases between species previously separated is also an issue. Human activities affected by change in traditional lifestyles, access to sea passages and potential for mineral deposits including oil. Rising sea levels led to coastal inundation, salinization, flooding and disruption. please use level descriptors 1 10 Question Answer Marks 3(b) The question requirements are: • to show understanding of international protocols • to describe how international protocols are agreed and why they are needed • to assess the success of named international protocols. Indicative content: The main agreement is the united nations framework convention on climate change (UNFCCC) which was adopted at Rio in 1992. Kyoto followed to establish a period of reduction and this was extended by the Doha amendment. Paris followed in 2015. Pollution crosses international boundaries so cooperation and agreement are needed to control the effects – climate change. The impact of climate change varies from country to country, e.g. changing sea levels. The contribution to climate change is connected to level of economic development including reliance on fossil fuels or renewable resources for power. International protocols are hard to agree and enforce. The first agreements only applied to developed countries and had little of the desired effect regarding climate change reduction. Later agreements included the developing countries but didn’t require signing, e.g. Kyoto which wasn’t signed by the USA. Subsequent agreements are under pressure, e.g. USA may pull out of Paris. Monitoring is a politically sensitive issue. please use level descriptors 2 30

This question in 8291/21 Oct/Nov 2019

2 (a) Fig. 2.1 shows the distribution of the tundra biome. Arctic Circle, 66.5 °N Tropic of Cancer, 23.5 °N Equator Tropic of Capricorn, 23.5 °S Key tundra biome Fig. 2.1 (i) Describe the distribution of the tundra biome shown in Fig. 2.1. … … … … [2] (ii) State the two main abiotic factors which contribute to the distribution of the tundra biome shown in Fig. 2.1. 1 … 2 … [2] (b) Fig. 2.2 is a food chain found in the tundra biome. Lichen Caribou Arctic Wolf Fig. 2.2 (i) State what is represented by the arrows in the food chain shown in Fig. 2.2. … … … … [2] (ii) Suggest why food chains in the tundra biome are short. … … … … [2] (c) Fig. 2.3 is an extract from a local news webpage. With more people moving to the tundra to work in mines and on oil rigs, more towns and roads have been built. The building of other structures, such as the Trans-Alaska Oil Pipeline, have caused disruption to species such as the Arctic Wolf. In addition, pesticides have been used to control large swarms of insects, which migrating birds rely on for food in the tundra. Fig. 2.3 (i) Suggest three ways in which human activities in Fig. 2.3 have caused disruption to the habitat of the Arctic Wolf. … … … … … … [3] (ii) Explain why the use of pesticides to control insect populations might lead to the death of Arctic birds of prey. … … … … … … [3] (d) Fig. 2.4 is an extract from an environmental journal. Permafrost is a characteristic of the tundra biome. The soil is frozen to a considerable depth meaning that trees cannot grow there. The permafrost acts as a store of water, methane and carbon dioxide. The winter months of January and February 2018 saw a change in weather patterns with unusually high temperatures in the arctic tundra, leading to melting of some of the permafrost. Fig. 2.4 Explain how the melting of some of the permafrost might affect coastal communities and global weather patterns. … … … … … … … … … … [6] [Total: 20]

20 marks

Mark scheme: 2(a)(i) near the North Pole / top of the world; above 60 °N latitude; on or close to the Arctic circle; northern Canada, Alaska, northern Scandinavia and Siberia; 2(a)(ii) temperature; moisture / rainfall / precipitation; 2 Question Answer Marks 2(b)(i) the transfer of energy; from prey to predator / from one organism to another / through feeding; 2 2(b)(ii) harsh environment; short summer means abundance is very short lived; means food chains are fragile; populations are (relatively) small; biodiversity is (relatively) low; Less energy available to higher levels max 2 2(c)(i) hunting / shooting; roads disrupt territories; risk of collisions; settlements disrupt prey animals’ behaviour; populations decline / relocate; poisoning (deliberate / accidental); bioaccumulation; max 3 2(c)(ii) insects contain the poison; insectivores ingest this poison; passes along the food chain; becomes more concentrated; bioaccumulation; top predator gets lethal / damaging dose of insecticide; gyrfalcons die / have reduced reproduction; max 3 Question Answer Marks 2(d) water stored as permafrost released; leads to more water in rivers and streams; increasing likelihood of flooding; water runs into the oceans; leading to rising sea levels; causing flooding of coastal communities; increasing salinisation of coastal soils / land; melting of the permafrost releases carbon dioxide store / methane; this is no longer locked up / released into the atmosphere; extra carbon dioxide / methane leads to increase in greenhouse gases; contributes to global warming; more extreme weather patterns / global weather pattern is uncertain as could lead to feedback loops; computer models vary in their predictions of feedback loops; more storms leading to coastal damage; decrease albedo as permafrost melts; max 6

This question in 8291/22 May/June 2020

2 (a) Fig. 2.1 shows the distribution of the tundra biome. Arctic Circle, 66.5 °N Tropic of Cancer, 23.5 °N Equator Tropic of Capricorn, 23.5 °S Key tundra biome Fig. 2.1 (i) Describe the distribution of the tundra biome shown in Fig. 2.1. … … … … [2] (ii) State the two main abiotic factors which contribute to the distribution of the tundra biome shown in Fig. 2.1. 1 … 2 … [2] (b) Fig. 2.2 is a food chain found in the tundra biome. Lichen Caribou Arctic Wolf Fig. 2.2 (i) State what is represented by the arrows in the food chain shown in Fig. 2.2. … … … … [2] (ii) Suggest why food chains in the tundra biome are short. … … … … [2] (c) Fig. 2.3 is an extract from a local news webpage. With more people moving to the tundra to work in mines and on oil rigs, more towns and roads have been built. The building of other structures, such as the Trans-Alaska Oil Pipeline, have caused disruption to species such as the Arctic Wolf. In addition, pesticides have been used to control large swarms of insects, which migrating birds rely on for food in the tundra. Fig. 2.3 (i) Suggest three ways in which human activities in Fig. 2.3 have caused disruption to the habitat of the Arctic Wolf. … … … … … … [3] (ii) Explain why the use of pesticides to control insect populations might lead to the death of Arctic birds of prey. … … … … … … [3] (d) Fig. 2.4 is an extract from an environmental journal. Permafrost is a characteristic of the tundra biome. The soil is frozen to a considerable depth meaning that trees cannot grow there. The permafrost acts as a store of water, methane and carbon dioxide. The winter months of January and February 2018 saw a change in weather patterns with unusually high temperatures in the arctic tundra, leading to melting of some of the permafrost. Fig. 2.4 Explain how the melting of some of the permafrost might affect coastal communities and global weather patterns. … … … … … … … … … … [6] [Total: 20]

20 marks

Mark scheme: 2(a)(i) near the North Pole / top of the world; above 60 °N latitude; on or close to the Arctic circle; northern Canada, Alaska, northern Scandinavia and Siberia; 2(a)(ii) temperature; moisture / rainfall / precipitation; 2 Question Answer Marks 2(b)(i) the transfer of energy; from prey to predator / from one organism to another / through feeding; 2 2(b)(ii) harsh environment; short summer means abundance is very short lived; means food chains are fragile; populations are (relatively) small; biodiversity is (relatively) low; Less energy available to higher levels max 2 2(c)(i) hunting / shooting; roads disrupt territories; risk of collisions; settlements disrupt prey animals’ behaviour; populations decline / relocate; poisoning (deliberate / accidental); bioaccumulation; max 3 2(c)(ii) insects contain the poison; insectivores ingest this poison; passes along the food chain; becomes more concentrated; bioaccumulation; top predator gets lethal / damaging dose of insecticide; gyrfalcons die / have reduced reproduction; max 3 Question Answer Marks 2(d) water stored as permafrost released; leads to more water in rivers and streams; increasing likelihood of flooding; water runs into the oceans; leading to rising sea levels; causing flooding of coastal communities; increasing salinisation of coastal soils / land; melting of the permafrost releases carbon dioxide store / methane; this is no longer locked up / released into the atmosphere; extra carbon dioxide / methane leads to increase in greenhouse gases; contributes to global warming; more extreme weather patterns / global weather pattern is uncertain as could lead to feedback loops; computer models vary in their predictions of feedback loops; more storms leading to coastal damage; decrease albedo as permafrost melts; max 6

This question in 8291/23 May/June 2020

1 (a) Fig. 1.1 shows the various stores of water found in the hydrosphere. freshwater lakes groundwater inland sea 0.009% 0.008% salt water 97.2% 2.8% 0.02% rivers 0.001% soil water ice sheets and glaciers atmosphere 0.005% 2.15% 0.001% Fig. 1.1 (i) Fig. 1.1 shows that 97.2% of water in the hydrosphere is salt water. State the type of water that makes up the remaining 2.8%. … [1] (ii) Calculate the percentage of water found as groundwater in the hydrosphere. … % [1] (iii) Describe two environmental problems which might be caused by the melting of ice sheets and glaciers. … … … … … … … … [4] (b) Aquifers are underground stores of groundwater. The three types of aquifer are confined, unconfined and perched. (i) Complete Table 1.1 by matching the type of aquifer to the correct description. confined unconfined perched Table 1.1 description type of aquifer an aquifer which is found above the water table where an impermeable layer of rock or material lies above the regional water table an aquifer where the water from the ground above is prevented from seeping in by a layer of impermeable rock or material lying above the aquifer an aquifer where water from the ground directly above can seep into the aquifer [2] (ii) State two causes of groundwater depletion from aquifers. … … … [2] (iii) Explain two strategies to conserve groundwater in aquifers. … … … … … … … … [4] (c) As the population of an area increases, the demands for water change from those of a rural area to those of an urban area. Describe and explain the changes in demand for water as an area becomes more urbanised. … … … … … … … … … … [5] (d) The creation of an artificial reservoir can provide access to water for many people. Suggest one disadvantage of the creation of an artificial reservoir. … … [1] [Total: 20]

20 marks

Mark scheme: 1(a)(i) fresh (water) 1 1(a)(ii) 0.63 (%); 1 1(a)(iii) increased flow of water into streams and rivers; leads to increased flooding; increased flow into seas from rivers; raises sea-level; increases risk of coastal flooding; damage to communities; loss of coastal areas / erosion; loss of land / damage to infrastructure; increased risk of salinisation of coastal soils; loss of land for agriculture; loss of annual melt waters; affects some agricultural practices; affects soil fertility; max 4 4 Question Answer Marks 1(b)(i) description type of aquifer an aquifer which is found above the water table where an impermeable layer of rock or material lies above the regional water table perched an aquifer where the water from the ground above is prevented from seeping in by a layer of impermeable rock or material lying above the aquifer confined an aquifer where water from the ground directly above can seep into the aquifer unconfined one correct; all three correct; 2 1(b)(ii) over-use / demand; for domestic / industrial / agricultural use; lack of rainfall / drought conditions; due to climate change / natural cycles; over-pumping could lead to salt intrusion in coastal aquifers reducing availability of freshwater; max 2 2 Question Answer Marks 1(b)(iii) education; to reduce demand for water; to encourage less wastage; legislation; to limit amounts that can be pumped for industrial / agricultural use; public attitudes; campaigns for reducing water use and waste; named example, e.g. not washing cars; use of grey water; to irrigate plants and gardens; to recycle / re-use water; max 4 4 Question Answer Marks 1(c) population increases; so greater demand for water; change from agricultural use to domestic use; as size of residential areas increases; increase in use for non-essential purposes; described, e.g. watering gardens / cleaning cars; increase in waste of water; larger population more likely to waste water than smaller rural population; max 5 5 1(d) destruction of habitats; noise during construction; displacement of people / loss of traditional jobs; disruption of river flow / annual flooding affected; silting downstream of the dam; max 1 1

This question in 8291/22 Oct/Nov 2020

1 (a) Water withdrawal is the total volume of water removed from a water source. Fig. 1.1 shows water withdrawal as a percentage of total water available for 1995 and predicted for 2025. 1995 2025 Water withdrawal as a percentage of NorthNorth Asia total water available AmericaAmerica more than 40% from 20% to 10% AfricaAfrica SouthSouth OceaniaOceania from 40% to 20% less than 10% AmericaAmerica Fig. 1.1 (i) Describe changes in water withdrawal in 1995 and predicted for 2025 shown in Fig. 1.1. … … … … … … [3] (ii) Suggest two causes of the predicted changes shown in Fig. 1.1. … … … … [2] (iii) Describe two strategies to manage the conservation of water. … … … … [2] (b) Fig. 1.2 shows the percentage of water consumption by sector in Egypt and the USA in 2019. Egypt USA Key agriculture domestic industrial Fig. 1.2 (i) Suggest one reason for the difference in water consumption in Egypt and the USA in the domestic and industrial sectors shown in Fig. 1.2. domestic … … industrial … … [2] (ii) Egypt supplies some of its freshwater by desalinisation. Explain how the process of desalinisation produces freshwater from seawater. … … … … … … … … [4] (iii) Describe advantages and disadvantages of using desalinisation to supply freshwater. advantages … … … … disadvantages … … … … [4] (c) Approximately 2% of the world’s water is freshwater. Explain how climate change impacts the availability of freshwater. … … … … … … [3] [Total: 20]

20 marks

Mark scheme: 1(a)(i) areas facing shortage are increasing / more countries in highest group; most spread across Middle East / Asia and North Africa; almost entirely northern hemisphere; stays the same / no change in South America / Oceania; USA moves into higher category; use of correct data in support of a change; max 3 1(a)(ii) increasing aridity / less precipitation; persistent drought; climate change; likely poor water management; population not conserving water; increased population; increased industrialisation / increasing number of industries; increased irrigation in agriculture; max 2 2 1(a)(iii) education; not doing things with running water; reduce amount in toilets; not washing cars; repair leaks; improve catchment and storage; provide a new source / alternative source e.g. desalination; method / type of recycling / re-using ‘waste’ water; max 2 2 Question Answer Marks 1(b)(i) Domestic Egypt has less developed infrastructure; Egypt has less sanitation; Egypt arid; USA has increased population / more people; Industrial USA more industrialised; USA is more economically developed; max 2 2 1(b)(ii) sea water is filtered; to remove solids and other unwanted particles; passed through membranes; reverse osmosis occurs; separating dissolved minerals / salts; freshwater treated to health standards; max 4 4 Question Answer Marks 1(b)(iii) Advantages it provides potable water for people / livestock; in arid areas; it provides water for agriculture / horticulture; it uses an available / abundant resource; it isn’t reliant on climate / rainfall; preserves / reduces drawdowns from natural sources e.g. aquifers / reservoirs; Disadvantages costly; consumes a lot of energy / resources; large volume of waste water; has to be built in coastal areas / needs infrastructure / transport; environmental issues; removes some of the taste of water; max 4 4 1(c) increasing temperature / global warming; increases evaporation / groundwater evaporates; more / less rainfall; extreme weather events such as flooding, storm surges, drought; leads to contamination of freshwater supplies; glaciers melt; increased flow in rivers; increased flow to oceans; polar ice melts faster; freshwater to seawater increases; max 3 3

This question in 8291/21 May/June 2021

4 Fig. 4.1 shows sea level change using estimates from the past, actual records and predictions for the future. 500 estimates records predictions 400 300 sea level 200 change / mm 100 0 –100 –200 1800 1850 1900 1950 2000 2050 2100 year Fig. 4.1 (a) Describe and explain the data trends in the estimates, actual records and predictions shown in Fig. 4.1. [10] (b) To what extent are international protocols successful in managing the causes of sea level change? Use examples to support your answer. [30] [Total: 40]

40 marks

Mark scheme: 4(a) The estimates of the past are broad and relatively flat, because they are based on little evidence and taken from journals and amateur observations. Hence, they are rather generalised. The instrumental record is narrower in range because they are based on scientific records gathered using specialised recording instruments which, as time progresses, are more accurate so the band narrows. The projections for the future are based on educated calculations but as time increases, they become less accurate so the band broadens. Overall the trend is upwards. 4(b) The question requirements are: • demonstrate knowledge of the international protocols • show understanding of the difficulty in achieving and monitoring the protocols • assess the relative success of chosen examples. Indicative content: Candidates should use a range of examples which could include Montreal, Kyoto and Paris. More recent declarations are also valid. Understanding the need to reduce carbon dioxide and methane releases as well as other related policies in order to slow the climate change resulting from these emissions. Candidates need to refer to rising sea levels and other influences such as melting glaciers and polar ice. The difficulties in getting agreement between countries of differing levels of economic development, environmental policies and political ideologies as well as the problems of monitoring and enforcing these between borders and countries. Assessment of the relative success should be made. 30 please use level descriptors 1 please use level descriptors 2

This question in 8291/22 Oct/Nov 2021

3 (a) A conservationist uses aerial photographs to estimate the population of a species of bird. Fig. 3.1 shows a drawing of the position of some birds from an aerial photograph using a grid. 1 2 3 4 5 A B C D E F G Fig. 3.1 (i) Complete Table 3.1 to record the number of birds in the grid squares A4 and D3. Table 3.1 A B C D E F G 1 3 0 3 3 1 1 1 2 6 2 3 5 5 6 3 3 4 1 5 … 7 3 5 4 … 4 4 5 7 2 7 5 3 5 3 5 8 3 5 [2] (ii) Describe the benefits and limitations of using aerial photographs to survey the population of birds. benefits … … … … limitations … … … … [4] (b) The formula shows Simpson’s index of diversity. n 2 D = 1 / -f d N n p Simpson’s index of diversity is a measure of diversity that takes into account the number of species present and the relative abundance of each species. The conservationist uses Simpson’s index of diversity to analyse data from an aerial photograph in location X. Table 3.2 shows the data from the aerial photograph for location X. Table 3.2 n = 2 n n species number of N d N n individuals Canada goose 54 0.58 0.34 sandhill crane 12 0.13 0.017 snow goose 26 0.28 0.078 bald eagle 1 0.011 0.00012 N = total number of all individuals 93 (i) Use the formula to determine a value for Simpson’s index of diversity for location X. Simpson’s index of diversity = … [2] (ii) Simpson’s index of diversity for two other locations Y and Z are shown in Table 3.3. Table 3.3 location Simpson’s index of diversity Y 0.66 Z 0.75 Compare the diversity of species in locations Y and Z. … … [1] (c) Fig. 3.2 is a drawing of a sandhill crane. Fig. 3.2 The adult sandhill crane is 80–136 cm tall and has a wingspan of over 180 cm. The conservationist wants to monitor the population of sandhill cranes using a capture-mark-recapture method. (i) Outline the capture-mark-recapture method the conservationist can use. … … … … … … [3] (ii) State two assumptions that must be made when using capture-mark-recapture data. 1 … … 2 … … [2] (d) From late February to early April over 600 000 sandhill cranes fly to the wetlands of Nebraska, in the midwest of the USA. This is called migration. The birds feed on land or in shallow marshes to fatten up before they continue their migration north to their summer breeding grounds. Fig. 3.3 shows part of a food web. eagle sandhill crane small bird frog small fish zooplankton algae plants and seeds Fig. 3.3 (i) Identify the maximum number of trophic levels in this food web. … [1] (ii) Use Fig. 3.3 to write a food chain for the sandhill crane that includes only one producer, one primary consumer and one secondary consumer. … [1] (e) Banning the hunting of sandhill cranes or requiring permits to hunt them helps to conserve the population of sandhill cranes. Fig. 3.4 shows a sign also used to help conserve the population of sandhill cranes. Fig. 3.4 Suggest why these three strategies help to conserve the population of sandhill cranes. … … … … … … [3] (f) Climate change is a threat to the sandhill crane. Suggest why climate change could decrease the population of sandhill cranes. Give reasons for your answer. … … … … … … … … [4] [Total: 23]

23 marks

Mark scheme: 3(a)(i) A4: 4; D3: 5; 2 3(a)(ii) max [4] benefits max 3: can be counted remotely; data can be checked / hard copy of data; avoids bias; large areas can be covered; automated; doesn’t harm the birds / birds not disturbed; limitations max 3: relies on photographing all the birds / birds move; need aeroplane or satellite or drone to take the images / costly; difficult to count if birds on a grid line; reliant on suitable weather conditions; reliant on lack of dense groundcover; potential distortion (due to oblique angle); difficult to identify species of bird; 4 3(b)(i) 0.44; (1 – M1 =) 0.56; 2 3(b)(ii) Z is more diverse (than Y); 1 3(c)(i) any three from: tag / named example e.g. leg rings / tags / chip; recapture idea of capture: marked AND unmarked / random capture; named method of estimating population: Lincoln index; 3 Question Answer Marks 3(c)(ii) any two from: no death / no change in survival rate; no births; no migration; sampling methods are identical to first capture; random mixing of population; 2 3(d)(i) 5; 1 3(d)(ii) algae  zooplankton  (sandhill) crane; OR plants/seeds  (sandhill) crane  eagle 1 3(e) any three from: restrict number of birds hunted / number of birds killed; restricted times/season for hunting; enables birds to reproduce; birds given time to fatten (ready for migration); (sign) education / awareness; 3 3(f) loss of habitat / wetlands dry up; alter migration; loss of other species / loss of food source / disrupt food chain; introduces, invasive species/predators; 4

This question in 8291/22 May/June 2022

3 (a) A conservationist uses aerial photographs to estimate the population of a species of bird. Fig. 3.1 shows a drawing of the position of some birds from an aerial photograph using a grid. 1 2 3 4 5 A B C D E F G Fig. 3.1 (i) Complete Table 3.1 to record the number of birds in the grid squares A4 and D3. Table 3.1 A B C D E F G 1 3 0 3 3 1 1 1 2 6 2 3 5 5 6 3 3 4 1 5 … 7 3 5 4 … 4 4 5 7 2 7 5 3 5 3 5 8 3 5 [2] (ii) Describe the benefits and limitations of using aerial photographs to survey the population of birds. benefits … … … … limitations … … … … [4] (b) The formula shows Simpson’s index of diversity. n 2 D = 1 / -f d N n p Simpson’s index of diversity is a measure of diversity that takes into account the number of species present and the relative abundance of each species. The conservationist uses Simpson’s index of diversity to analyse data from an aerial photograph in location X. Table 3.2 shows the data from the aerial photograph for location X. Table 3.2 n = 2 n n species number of N d N n individuals Canada goose 54 0.58 0.34 sandhill crane 12 0.13 0.017 snow goose 26 0.28 0.078 bald eagle 1 0.011 0.00012 N = total number of all individuals 93 (i) Use the formula to determine a value for Simpson’s index of diversity for location X. Simpson’s index of diversity = … [2] (ii) Simpson’s index of diversity for two other locations Y and Z are shown in Table 3.3. Table 3.3 location Simpson’s index of diversity Y 0.66 Z 0.75 Compare the diversity of species in locations Y and Z. … … [1] (c) Fig. 3.2 is a drawing of a sandhill crane. Fig. 3.2 The adult sandhill crane is 80–136 cm tall and has a wingspan of over 180 cm. The conservationist wants to monitor the population of sandhill cranes using a capture-mark-recapture method. (i) Outline the capture-mark-recapture method the conservationist can use. … … … … … … [3] (ii) State two assumptions that must be made when using capture-mark-recapture data. 1 … … 2 … … [2] (d) From late February to early April over 600 000 sandhill cranes fly to the wetlands of Nebraska, in the midwest of the USA. This is called migration. The birds feed on land or in shallow marshes to fatten up before they continue their migration north to their summer breeding grounds. Fig. 3.3 shows part of a food web. eagle sandhill crane small bird frog small fish zooplankton algae plants and seeds Fig. 3.3 (i) Identify the maximum number of trophic levels in this food web. … [1] (ii) Use Fig. 3.3 to write a food chain for the sandhill crane that includes only one producer, one primary consumer and one secondary consumer. … [1] (e) Banning the hunting of sandhill cranes or requiring permits to hunt them helps to conserve the population of sandhill cranes. Fig. 3.4 shows a sign also used to help conserve the population of sandhill cranes. Fig. 3.4 Suggest why these three strategies help to conserve the population of sandhill cranes. … … … … … … [3] (f) Climate change is a threat to the sandhill crane. Suggest why climate change could decrease the population of sandhill cranes. Give reasons for your answer. … … … … … … … … [4] [Total: 23]

23 marks

Mark scheme: 3(a)(i) A4: 4; D3: 5; 2 3(a)(ii) max [4] benefits max 3: can be counted remotely; data can be checked / hard copy of data; avoids bias; large areas can be covered; automated; doesn’t harm the birds / birds not disturbed; limitations max 3: relies on photographing all the birds / birds move; need aeroplane or satellite or drone to take the images / costly; difficult to count if birds on a grid line; reliant on suitable weather conditions; reliant on lack of dense groundcover; potential distortion (due to oblique angle); difficult to identify species of bird; 4 3(b)(i) 0.44; (1 – M1 =) 0.56; 2 3(b)(ii) Z is more diverse (than Y); 1 3(c)(i) any three from: tag / named example e.g. leg rings / tags / chip; recapture idea of capture: marked AND unmarked / random capture; named method of estimating population: Lincoln index; 3 Question Answer Marks 3(c)(ii) any two from: no death / no change in survival rate; no births; no migration; sampling methods are identical to first capture; random mixing of population; 2 3(d)(i) 5; 1 3(d)(ii) algae  zooplankton  (sandhill) crane; OR plants/seeds  (sandhill) crane  eagle 1 3(e) any three from: restrict number of birds hunted / number of birds killed; restricted times/season for hunting; enables birds to reproduce; birds given time to fatten (ready for migration); (sign) education / awareness; 3 3(f) loss of habitat / wetlands dry up; alter migration; loss of other species / loss of food source / disrupt food chain; introduces, invasive species/predators; 4

This question in 8291/23 May/June 2022

1 Fig. 1.1 is a map of Singapore, Southeast Asia. Singapore is comprised of 63 islands, with a total surface area of land of 721.5 km2. N Malaysia Singapore Strait Singapore Indonesia 0 10 km Key capital airport international boundary Fig. 1.1 In 2020, the population of Singapore was 5 850 000. (a) Singapore has a high population density. (i) Calculate the population density for Singapore in 2020. … people km–2 [1] (ii) Explain the challenges that a high population density can cause a country. … … … … … … [3] (b) Fig. 1.2 shows the population pyramid for Singapore in 2020. male age range female 100 + 95-99 90-94 85-89 80-84 75-79 70-74 65-69 60-64 55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4 0.4 0.3 0.2 0.1 0 0 0.1 0.2 0.3 0.4 population / million Fig. 1.2 (i) Compare the population structure of males and females in Singapore. … … … … … … … … [4] (ii) Suggest how this population pyramid indicates that Singapore has an economy of a high income country (HIC). … … … … [2] (c) Suggest why Singapore is at high risk from the effects of climate change. Give reasons for your answer. … … … … [2] (d) Solar radiation management (SRM) is a theoretical strategy to reduce the impact of climate change. (i) One SRM strategy is to spray sulfate aerosol particles into the stratosphere. Explain how this could reduce the impact of climate change. … … … … [2] (ii) Suggest why some scientists think investing in technology to reduce the combustion of fossil fuels is more important than investing in SRM technology. … … … … [2] [Total: 16]

16 marks

Mark scheme: Question Answer Marks 1(a)(i) 8108(.108108); 1 1(a)(ii) any three from: 3 limited land area to accommodate people / not enough houses; overcrowding; leads to spread of disease / named disease (more quickly); limited land area for infrastructure / roads; leads to increased house prices / land prices / negative economic impact on population; not enough jobs available; high level of car use / factory emissions; leads to congestion; leads to air pollution / acid rain / global warming / smog; effect of stated air pollution, e.g. acidification of lakes / climate change; limited green spaces / limited agricultural land / high level of urbanisation; leads to food shortages; leads to water shortages / water pollution; waste management; AVP; 1(b)(i) any four from: 4 (approximately) equal numbers / same trend; more females in older age / more females aged 70+ / woman live longer; more females in, working age / 15–39 age; no males in 100+ age range; 1(b)(ii) any two from: 2 high life expectancy / people live a long time / taller (than LIC); high(er) number of older dependents (than LIC); low(er) number of young dependents (than LIC); high(er) number of economically active (than LIC); indicates low birth / death rate; 1(c) any two from: 2 island / surrounded by sea; at risk from flooding; change in ocean / wind circulation; increased ocean temperatures lead to extreme weather events; high population density / limited land area: food / energy / water insecurity; 1(d)(i) (small amounts of) inbound sunlight are reflected back (into space); 2 cools planet / reduces global temperatures / reduces speed of climate change; 1(d)(ii) any two from: 2 combustion of fossil fuels produces, greenhouse gases / carbon dioxide; idea that SRM: does not reduce greenhouse gases / only deals with symptom not the problem / may only work for a short period / not a long-term solution; SRM: untested theory / might have negative effect, e.g. effect on ozone layer / health impact;

This question in 8291/21 Oct/Nov 2022

1 Fig. 1.1 is a map of Singapore, Southeast Asia. Singapore is comprised of 63 islands, with a total surface area of land of 721.5 km2. N Malaysia Singapore Strait Singapore Indonesia 0 10 km Key capital airport international boundary Fig. 1.1 In 2020, the population of Singapore was 5 850 000. (a) Singapore has a high population density. (i) Calculate the population density for Singapore in 2020. … people km–2 [1] (ii) Explain the challenges that a high population density can cause a country. … … … … … … [3] (b) Fig. 1.2 shows the population pyramid for Singapore in 2020. male age range female 100 + 95-99 90-94 85-89 80-84 75-79 70-74 65-69 60-64 55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4 0.4 0.3 0.2 0.1 0 0 0.1 0.2 0.3 0.4 population / million Fig. 1.2 (i) Compare the population structure of males and females in Singapore. … … … … … … … … [4] (ii) Suggest how this population pyramid indicates that Singapore has an economy of a high income country (HIC). … … … … [2] (c) Suggest why Singapore is at high risk from the effects of climate change. Give reasons for your answer. … … … … [2] (d) Solar radiation management (SRM) is a theoretical strategy to reduce the impact of climate change. (i) One SRM strategy is to spray sulfate aerosol particles into the stratosphere. Explain how this could reduce the impact of climate change. … … … … [2] (ii) Suggest why some scientists think investing in technology to reduce the combustion of fossil fuels is more important than investing in SRM technology. … … … … [2] [Total: 16]

16 marks

Mark scheme: Question Answer Marks 1(a)(i) 8108(.108108); 1 1(a)(ii) any three from: 3 limited land area to accommodate people / not enough houses; overcrowding; leads to spread of disease / named disease (more quickly); limited land area for infrastructure / roads; leads to increased house prices / land prices / negative economic impact on population; not enough jobs available; high level of car use / factory emissions; leads to congestion; leads to air pollution / acid rain / global warming / smog; effect of stated air pollution, e.g. acidification of lakes / climate change; limited green spaces / limited agricultural land / high level of urbanisation; leads to food shortages; leads to water shortages / water pollution; waste management; AVP; 1(b)(i) any four from: 4 (approximately) equal numbers / same trend; more females in older age / more females aged 70+ / woman live longer; more females in, working age / 15–39 age; no males in 100+ age range; 1(b)(ii) any two from: 2 high life expectancy / people live a long time / taller (than LIC); high(er) number of older dependents (than LIC); low(er) number of young dependents (than LIC); high(er) number of economically active (than LIC); indicates low birth / death rate; 1(c) any two from: 2 island / surrounded by sea; at risk from flooding; change in ocean / wind circulation; increased ocean temperatures lead to extreme weather events; high population density / limited land area: food / energy / water insecurity; 1(d)(i) (small amounts of) inbound sunlight are reflected back (into space); 2 cools planet / reduces global temperatures / reduces speed of climate change; 1(d)(ii) any two from: 2 combustion of fossil fuels produces, greenhouse gases / carbon dioxide; idea that SRM: does not reduce greenhouse gases / only deals with symptom not the problem / may only work for a short period / not a long-term solution; SRM: untested theory / might have negative effect, e.g. effect on ozone layer / health impact;

This question in 8291/23 Oct/Nov 2022

1 (a) Spraying aerosols into the stratosphere and growing crops with shiny leaves are two geo-engineering methods that can counteract climate change. (i) Explain how spraying aerosols into the stratosphere can counteract climate change. … … … … [2] (ii) Explain how growing crops with shiny leaves can counteract climate change. … … … … [2] (b) Researchers use computer models to predict the impact of geo-engineering strategies on climate change. Table 1.1 is a summary of the findings. Table 1.1 impact global increased number of people geo-engineering strategy temperature floods and adversely impacted reduced droughts / billion spraying aerosols into the yes yes 3 stratosphere growing crops with shiny yes yes 1.4 leaves (i) Suggest how managing the Earth’s climate can result in increased floods and droughts. … … … … [2] (ii) Evaluate the use of the geo-engineering strategies in Table 1.1 for counteracting climate change. … … … … [2] (iii) Suggest what further research can be carried out to confirm the impact of the geo-engineering strategies in Table 1.1. … … [1] (c) A report predicted how rising sea levels will result in coastal flooding in 2050. Table 1.2 shows the number of people predicted to be affected by coastal flooding for five countries. Table 1.2 number of people country / million China 93 Bangladesh 42 India 36 Vietnam 31 Indonesia 23 Plot the data as a bar chart. [4] (d) Explain why flooding can lead to water insecurity. … … … … … … [3] (e) Explain why drought leads to food shortages and malnutrition. … … … … … … [3] (f) A report by the World Health Organization stated that malnutrition causes 35% of all deaths in under five-year-olds. Fig. 1.1 shows the percentage of under five-year-old children who are underweight. Key percentage of under five-year-old children who are underweight >30 20–29.9 10–19.9 <10 no data Tropic of Cancer Equator Tropic of Capricorn Fig. 1.1 Describe the distribution of under five-year-old children who are underweight, shown in Fig. 1.1. … … … … … … [3] [Total: 22]

22 marks

Mark scheme: Question Answer Marks 1(a)(i) any two from: 2 reflect (incoming) solar radiation / (sun)light, back into space; before it reaches the Earth’s surface; reduces global temperatures; 1(a)(ii) any two from: 2 increases, albedo / reflectivity (of plants / Earth’s surface); reflect (incoming) solar radiation / (sun)light, back into space; reduces global temperatures; 1(b)(i) any two from: 2 changed (wind/atmospheric) circulation; adverse effect on rainfall / too much rain / too little rain; changed temperatures; more extreme weather conditions e.g. hurricanes / storms / heatwaves; 1(b)(ii) any two from: 2 Positives: both strategies reduce global temperatures; Negatives: both strategies cause adverse effects e.g. floods / drought; many people adversely impacted (due to floods / droughts) e.g. relocation; more people adversely impacted by spraying aerosols than growing crops with shiny leaves / 3 billion (aerosols) versus 1.4 billion (shiny leaves); but need to fix climate change regardless of cost; 1(b)(iii) any one from: 1 laboratory / small scale testing; field testing; repeat the (computer) models with different parameters e.g. measure, humidity / greenhouse gas concentration or named greenhouse gas; 1(c) axis labels: y-axis number of people / million AND x-axis country; 4 sensible linear scale to cover at least half the grid; bars equal width AND not touching; four or five correct plots; 1(d) any three from: 3 (flooding) contaminates / pollutes, water bodies; stated examples of contamination / pollution e.g. sewage / industrial waste / domestic waste / agricultural waste / fertilisers; water, cannot be drunk / is unsafe; (flooding can lead to) saltwater / seawater intrusion; damage to, infrastructure / distribution pipes / tanks (so distribution adversely affected); 1(e) any three from: 3 plants / crops, need water for growth; by photosynthesis; (lack of water) reduces crop yield / loss of crops / loss of livestock; leads to famine / starvation; leads to food insecurity; 1(f) any three from: 3 majority south of Tropic of Cancer; some north of Tropic of Cancer; between Tropic of Cancer and equator; underweight children in Africa / (South) Asia; relevant quoted country / data e.g. high in India or Indian sub-continent / low in Americas;

This question in 8291/22 Oct/Nov 2023

3 An increase in wild fires is an impact of climate change. (a) Explain how climate change leads to wild fires. … … … … … … [3] (b) Table 3.1 shows the number of wild fires recorded in Brazil from 2013 to 2019. Table 3.1 Content removed due to copyright restrictions. (i) Plot the data in Table 3.1 as a bar chart. [4] (ii) Suggest why the actual number of wild fires in 2019 was greater than 80 500. … … [1] (c) Explain how climate change can cause extreme rainfall. … … … … … … [3] (d) In the year 2000, four different computer models were used to predict future changes to the mean global surface temperature. Fig. 3.1 shows these four predictions for global surface temperature compared to measured data from the year 2000. Key measured data model A model B model C model D 6 5 4 3 global surface temperature 2 change / °C 1 0 –1 –2 1900 1950 2000 2050 2100 year Fig. 3.1 (i) State what Fig. 3.1 shows about the global surface temperature before the year 2000. … [1] (ii) Suggest two reasons for the differences in the four predictions. 1 … … 2 … … [2] (e) Fig. 3.2 shows the locations of some research bases in Antarctica. Key research base Antarctic continent ice shelf Haakon VII Sea Weddell Sea Davis Sea Bellinghausen Sea South Pole Amundsen Mawson Sea Sea Ross Sea 0 1000 Dumont km D’urville Sea Fig. 3.2 (i) Suggest why climate change is a concern for Antarctica. … … [1] (ii) Describe how the impacts of tourism are controlled in Antarctica. … … … … … … [3] [Total: 18]

18 marks

Mark scheme: 3(a) any three from: 3 MP1 higher temperatures; MP2 drought; MP3 less rainfall; MP4 vegetation drier; 3(b)(i) MP1 axes labels e.g. y-axis label: number of (recorded) wild fires AND x-axis: year; 4 MP2 sensible linear scale, plotted points occupy half the grid; MP3 6–7 bars of correct height; MP4 bars drawn with a ruler and equal width and not touching; 3(b)(ii) any one from: 1 not all fires reported; AVP; 3(c) any three from: 3 MP1 global warming / increased temperatures; MP2 more evaporation; MP3 more convection; MP4 more moisture to form clouds; 3(d)(i) any one from: 1 MP1 lower value (than 2000 value); MP2 (from 1900 to 2000) gradually increasing; 3(d)(ii) any two from: 2 MP1 based on different theories / policies; MP2 different data used / stated example e.g. temperature; MP3 biased data; MP4 improved or different technology / knowledge; 3(e)(i) any one from: 1 MP1 increased temperatures can melt ice; MP2 many research bases on ice shelfs; MP3 loss of habitat / loss of biodiversity; 3(e)(ii) any three from: 3 MP1 Antarctic Treaty / legislation / international agreement; MP2 people not allowed to enter protected areas / restricted activities; MP3 waste management / waste taken away from Antarctica; MP4 permits for travel; MP5 guides required; MP6 restriction of tourist / ship numbers;

This question in 8291/22 May/June 2025

2 Albatross are birds. Many of the 22 species of albatross are listed by the International Union for Conservation of Nature (IUCN) Red List. (a) Describe how the IUCN Red List helps conserve biodiversity. … … … … [2] (b) Albatrosses make mud nests on the ground to lay their eggs. Fig. 2.1 shows albatrosses on the mud nests. mud nest Fig. 2.1 Suggest two reasons why these mud nests are at risk from climate change. 1 … … 2 … … [2] (c) Fig. 2.2 shows a food web for albatrosses. gulls small fish albatross octopus squid phytoplankton shrimp large fish Fig. 2.2 Write a food chain for the albatross. Start the food chain with a producer and include a total of four trophic levels. … [2] (d) Mercury is a toxic metal. The concentration of mercury in organisms in the food web in Fig. 2.2 is investigated. For albatrosses, their feathers are analysed. For the other organisms in the food web, their flesh is analysed. (i) Suggest two reasons why only the feathers are analysed for albatrosses. 1 … … 2 … … [2] (ii) The mean level of mercury in the prey of the albatross was 0.0005 μg per g. Circle the predicted mean level of mercury in albatrosses. Explain your answer. 0.0001 μg per g 0.0005 μg per g 3.88 μg per g … … [2] (e) Albatrosses can travel over 1500 km a day to find food. Suggest how radio tracking is used to record the distances albatrosses travel to find food. … … … … [2] (f) Satellite images from space are used to determine albatross population near Antarctica. Fig. 2.3 shows a satellite image of some nesting albatrosses. Key albatross 0 3 m Fig. 2.3 (i) Record the number of albatrosses shown in Fig. 2.3 as a tally. number of albatrosses [1] (ii) Crowd sourcing is used to count the number of albatrosses on each satellite image. Describe what is meant by crowd sourcing. … … [1] (iii) Suggest the benefits and limitations of using satellite images to determine the population of albatrosses. benefits … … … … limitations … … … … [4] (g) Different species of albatross build nests in the same area. A scientist uses Simpson’s index of diversity to investigate the different species of albatross in an area. D = 1 – (∑(nN) 2) State what each of the letters represent in this formula. ∑ … n … N … [3] [Total: 21]

21 marks

Mark scheme: 2(a) any two from: 2 M1 identifies threat status of organisms or species; M2 monitors, organisms / ecosystems; M3 raises awareness; M4 aims to influence policies or laws in favour of biodiversity; 2(b) any two from: 2 M1 increased, rainfall / flooding / sea level rise, washes away nests; M2 increased, storms / wind / extreme weather, blows away nests; M3 increased temperature / lack of rainfall, dries out or cracks mud; M4 loss of land due to sea level rise so less available land to build nests; M5 this increases competition for available land; 2(c) M1 phytoplankton; 2 M2 total of four levels and with arrows in correct direction; phytoplankton → small fish → large fish → albatross 2(d)(i) M1 don’t need to kill the albatross; 2 M2 (albatross are) listed in (IUCN) Red List / idea of being endangered or threatened; 2(d)(ii) M1 3.88 g per g circled; 2 M2 biomagnification / concentration (of toxins) increases up a food chain; 2(e) M1 tag or (radio) tracker fitted to bird; 2 M2 (location transmitted which is) received by GPS; 2(f)(i) tally used with 34 shown; 1 2(f)(ii) using large numbers of people / general public, to obtain data; 1 2(f)(iii) total four from: 4 max three benefits: M1 large area can be sampled; M2 do not need to go to where albatrosses are / Antarctica is difficult to get to; M3 does not disturb albatrosses / does not disturb environment; M4 quick to sample / quick to take images; M5 birds are not counted twice (in static image); max three limitations: M6 idea of big data / time consuming (to count or analyse all images); M7 idea of albatross huddled together so difficult to see or count individual birds; M8 can’t be used when cloudy; M9 expense (of satellite); M10 cannot identify different species; 2(g) M1  sum of (total); 3 M2 n number of individuals of each species (present in the sample); M3 N total number of all individuals in all species (present in sample);

This question in 8291/22 Oct/Nov 2025

4 (a) Fig. 4.1 shows a map of drought risk. Content removed due to copyright restrictions. Fig. 4.1 (i) Describe the distribution of countries with high drought risk. … … … … … [3] (ii) A lack of drinking water is an impact of drought. This can cause deaths. State three other impacts of drought. 1 … 2 … 3 … [3] (b) Fig. 4.2 shows climate data from a weather station in the Northern Territory, Australia. Content removed due to copyright restrictions. Fig. 4.2 (i) State the highest mean temperature. … °C [1] (ii) State which three months had the greatest mean rainfall. … and … and … [1] (iii) Suggest why the rate of primary productivity decreases during June to August near the location of this weather station. Use Fig. 4.2 to support your answer. … … … … [2] (c) Some areas of the Northern Territory have a grassland biome. Describe the soil type in a grassland biome. … … … … [2] (d) Cane toads are an invasive species in the Northern Territory. Explain the impacts of invasive species on biodiversity. … … … … … … [3] [Total: 15]

15 marks

Mark scheme: 4(a)(i) any three from: 3 M1 most of Europe / Eastern Europe / Southern Europe; M2 South Asia / Southeast Asia; M3 (mostly) north of Tropic of Cancer / in the region of Tropic of Cancer; M4 some countries bordering Equator; M5 named country e.g. Moldova / Ukraine / Bangladesh / India / Serbia; 4(a)(ii) any three from: 3 M1 wild fires; M2 crop failure / reduced crop yield; M3 food insecurity / famine / food shortages; M4 water insecurity / poor sanitation / disease; M5 lower HEP production; 4(b)(i) 32; 1 4(b)(ii) Jan and Feb and Dec; 1 4(b)(iii) any two from: 2 M1 low(est) rainfall / rainfall less than 5 mm; M2 water needed for photosynthesis; M3 green plants convert carbon dioxide and water to glucose and oxygen; 4(c) any two from: 2 M1 thick or deep layer of humus / thick or deep layer of decaying plants or animals; M2 high nutrients / high fertility / are fertile / high organic content; M3 reference to, moisture content / porosity / pH / colour; 4(d) any three from: 3 M1 compete with native organisms (for resources); M2 disrupt food chains; M3 spread disease; M4 alter habitats; M5 (leads to) loss of biodiversity / extinction (of native species);

This question in 8291/22 Oct/Nov 2025