Natural resourcesIB Environmental Systems and Societies SL: Topic test

1. 1
   In 2018 Cape Town, South Africa, came close to "Day Zero", the day when municipal taps would be turned off. Three years of drought had left the dams that supply the city at about 20% of their capacity. Residents were limited to 50 litres of water per person per day, and the city raised water prices and reduced pressure in the pipes. Together with other measures, these cut the city's water use by around half. The city also developed groundwater supplies and small desalination plants, and rain returned later in 2018.

   (a)

   Which statement best defines resource security?

   [1 mark]

   • AThe total amount of a resource in the ground
   • BThe ability of a society to ensure the long-term availability of enough of a resource to meet demand
   • CThe price at which a resource can be sold
   • DThe right of a country to export a resource

   (b)

   Which measure directly reduced demand for water in Cape Town?

   [1 mark]

   • ADeveloping groundwater supplies
   • BBuilding desalination plants
   • CWaiting for rainfall to return
   • DLimiting each person to 50 litres of water per day

   (c)

   Explain why water is classed as a renewable resource even though Cape Town nearly ran out.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   New York City obtains most of its drinking water from the Catskill and Delaware watersheds, about 200 km to the north. Forests, wetlands and soils in the watersheds filter and clean the water, and for many years the city did not need to treat it by filtration. In the 1990s pollution from farms and development threatened the quality of the water. Instead of building a filtration plant, which was estimated to cost several billion dollars, the city paid landowners to protect the watershed and improve farming practices.

   (a)

   The cleaning of water by forests and wetlands is an example of which type of ecosystem service?

   [1 mark]

   • ARegulating
   • BProvisioning
   • CCultural
   • DTechnological

   (b)

   The drinking water supplied each year to the city is best described as which of the following?

   [1 mark]

   • ANatural capital
   • BA non-renewable resource
   • CNatural income
   • DA resource with only intrinsic value

   (c)

   Explain why describing the watershed as "natural capital" reflects a particular perspective on nature.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   In 2022 a country generated 200 terawatt-hours (TWh) of electricity. Coal produced 90 TWh, natural gas 50 TWh, hydropower 30 TWh, wind 20 TWh and solar 10 TWh. The government plans to increase the share of wind and solar power over the next ten years. Wind and solar output varies with the weather and the time of day, while demand for electricity is highest in the evening.

   (a)

   Calculate the percentage of the country's electricity that came from renewable sources in 2022. Show your working.

   [3 marks]

   (b)

   Discuss the problems that intermittent supply could cause for the plan to increase wind and solar power, and suggest ways to deal with them.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Each year Chile receives tens of thousands of tonnes of used clothing, much of it imported through the free port of Iquique from Europe, Asia and the United States. Some is sold on in other Latin American countries, but an estimated 39,000 tonnes a year is left unsold and dumped in the Atacama Desert. Most clothing now contains synthetic fibres, which do not decompose for a very long time. The piles are sometimes burned, producing toxic smoke, and they are visible from space. Many of the garments were made in countries far from where they were bought and thrown away.

   (a)

   Explain how the production, treatment and management of waste can have environmental and social impacts in a different location from where it was generated.

   [6 marks]

   (b)

   Evaluate how the principles of a circular economy could reduce the problem of clothing waste.

   [6 marks]

   Total for question 4: 12 marks

5. 5
   Iceland produces almost all of its electricity from hydropower and geothermal power. It is a volcanic island with many glaciers and high rainfall, and hot water from geothermal fields heats most of its homes. More than half of the electricity is used by aluminium smelters, which are attracted by the cheap electricity. Iceland has no fossil fuel reserves, and it imports petrol and diesel for road transport and for its large fishing fleet.

   (a)

   Which factor best explains Iceland's choice of electricity sources?

   [1 mark]

   • AIt has large reserves of coal and gas
   • BIt has a very large population needing power
   • CIt has a low demand for energy
   • DIt has abundant geothermal heat and rivers fed by glaciers and rain

   (b)

   Why is geothermal power less affected by intermittency than wind or solar power?

   [1 mark]

   • AIt is available only when the sun shines
   • BIt provides a continuous output because the heat source is always present
   • CIt uses up a finite stock of fuel
   • DIt cannot be used for heating

   (c)

   Explain how energy conservation and efficiency could reduce Iceland's dependence on imported fuel.

   [2 marks]

   Total for question 5: 4 marks

6. 6
   In Germany most plastic and metal drinks containers carry a deposit of 25 cents, which is refunded when the container is returned to a shop. Many glass and plastic bottles are refillable, washed and reused many times, and the rest are collected and recycled into new bottles. More than 90% of deposit containers are returned. Germany also collects food and garden waste separately, and it composts or digests this rather than burying it. The schemes aim to cut the amount of waste that is sent for disposal.

   (a)

   Which waste management strategy is the most sustainable?

   [1 mark]

   • ABurying waste in landfill
   • BBurning waste to recover energy
   • CReducing the amount of waste produced, for example by refilling bottles
   • DRecycling waste after it has been collected

   (b)

   Which statement best describes a circular economy?

   [1 mark]

   • AMaterials are kept in use for as long as possible and waste is designed out
   • BResources are used once and then thrown away
   • CWaste is moved to other countries for disposal
   • DOnly renewable resources are used for energy

   (c)

   Explain why the deposit scheme is an example of a circular economy approach.

   [2 marks]

   Total for question 6: 4 marks

7. 7
   A city of 800,000 people produces 400,000 tonnes of solid domestic waste a year. Of this, 220,000 tonnes go to a landfill site, 80,000 tonnes are burned in an incinerator that generates electricity, 70,000 tonnes are recycled and 30,000 tonnes of food and garden waste are composted. The landfill site is nearly full, and the city is deciding how to manage its waste in future.

   (a)

   Calculate the percentage of the city's solid domestic waste that is recycled or composted. Show your working.

   [3 marks]

   (b)

   Compare the environmental impacts of landfill and incineration as options for waste disposal in the city.

   [4 marks]

   Total for question 7: 7 marks

8. 8
   Kenya produces about 40% of its electricity from geothermal power, much of it at Olkaria in the Great Rift Valley, close to Hell's Gate National Park. Hot rock lies close to the surface there because of the volcanic activity of the Rift. Kenya also has hydropower, wind and solar power, but it has no large fossil fuel reserves of its own and imports petroleum. Geothermal plants have high building costs but low running costs. Some Maasai families were moved to make way for the Olkaria IV plant, and compensation was disputed. The wells also release small amounts of carbon dioxide and hydrogen sulfide.

   (a)

   Explain the factors that have affected Kenya's choice of energy sources.

   [6 marks]

   (b)

   Evaluate the sustainability of geothermal power in Kenya.

   [6 marks]

   Total for question 8: 12 marks

End of questions