Cambridge IGCSE Geography (0460): Theme 3.7 – Environmental risks of economic development – Revision Notes

For full explanations, worked answers and evaluation, read the Environmental risks study guide first.

These notes cover section 3.7 Environmental risks of economic development of the Cambridge IGCSE Geography (0460) syllabus for examination in 2025 and 2026, Version 2 (published November 2022). The section is assessed in Paper 1 Geographical Themes (1 hour 45 minutes, 75 marks), where you answer three 25-mark questions, one from each section. Paper 2 Geographical Skills can also set knowledge questions on the themes, so pollution or soil data may appear there.

Practise with the Environmental risks practice questions. Track your progress on the Cambridge IGCSE Geography hub and the IGCSE Geography checklist.

What you must be able to do

1. Describe how economic activities may pose threats to the natural environment and people, locally and globally. The guidance names soil erosion, desertification, enhanced global warming and pollution (water, air, noise, visual).
2. Demonstrate the need for sustainable development and management.
3. Understand the importance of resource conservation.
4. Case study: an area where economic development is taking place and causing the environment to be at risk.

Key terms

Term	Definition
Soil erosion	Removal of topsoil by water or wind faster than new soil forms
Desertification	Degradation of land in arid and semi-arid areas so it becomes more desert-like
Overgrazing	Keeping more animals on land than the vegetation can support
Overcultivation	Growing crops so intensively that the soil loses nutrients and structure
Natural greenhouse effect	Gases such as carbon dioxide and methane trap heat and keep the Earth warm enough for life
Enhanced global warming	Extra warming caused by greenhouse gases added by human activity
Gas flaring	Burning off gas that comes up with oil, instead of capturing it
Eutrophication	Nutrients from fertiliser or sewage cause algae to grow; their decay uses up oxygen and fish die
Acid rain	Rain made acidic by sulphur dioxide and nitrogen oxides from burning fuels
Noise pollution	Unwanted or harmful sound, for example from airports or quarry blasting
Visual pollution	Features that spoil the look of a landscape, such as spoil heaps or pylons
Sustainable development	Development that meets present needs without compromising the ability of future generations to meet theirs
Resource conservation	Using natural resources carefully so that they last longer and are not wasted
Environmental impact assessment	A study of a project’s likely effects on the environment before it is approved

Threats at a glance

Threat	Economic activity	Local effect	Wider or global effect
Soil erosion	Deforestation, overgrazing, ploughing down slopes	Lower crop yields; gullies	Silt fills rivers and reservoirs downstream
Desertification	Overgrazing, overcultivation, fuelwood cutting	Land can no longer support farming	People migrate; food shortages across a region
Enhanced global warming	Burning fossil fuels, deforestation, cattle, rice, flaring	Hotter, drier local conditions	Sea-level rise; extreme weather worldwide
Water pollution	Factories, sewage, fertiliser, oil spills	Fish die; unsafe drinking water	Pollution carried downstream or into the sea
Air pollution	Chimneys, vehicles, power stations	Breathing illnesses; smog	Acid rain across borders; greenhouse gases
Noise pollution	Airports, roads, factories, quarries	Stress, poor sleep, wildlife disturbed	Mainly local
Visual pollution	Quarries, spoil heaps, power lines	Spoilt landscapes; fewer tourists	Mainly local

Case studies and key sources at a glance

Who or where	What	Key details	One evaluation point
Niger Delta, Nigeria (case study)	Oil extraction putting the environment and people at risk	Oil found at Oloibiri, 1956; oil spills, gas flaring, mangroves and fishing harmed	Views differ on causes: oil companies stress theft and sabotage, communities stress poor maintenance, and critics say government enforcement is weak. New spills continue, so prevention matters more than repair
Ogoniland (UNEP, 2011)	United Nations assessment of oil pollution	Over 4,000 samples from more than 200 sites; benzene in one community’s drinking water about 900 times the WHO guideline; up to 30 years to recover; about US$1 billion for the first five years	Strong evidence base, but recommendations depend on governments acting
Bodo, Ogoniland	Two Shell pipeline spills that began in 2008	2015 settlement of £55 million after a London court case	Compensation helps people but does not clean the creeks by itself
Great Green Wall, Sahel	Response to desertification	Endorsed by the African Union in 2007; about 8,000 km; aim to restore 100 million hectares by 2030	Progress slower than planned; needs local people to protect new trees
Brundtland Report (1987)	Our Common Future	Gave the standard definition of sustainable development	Widely used, but does not say how to balance jobs against the environment
Paris Agreement (2015)	Global climate agreement	Aim to limit warming to well below 2 °C	Relies on each country keeping its own promises

Must-know distinctions

• Natural greenhouse effect vs enhanced global warming: the first is natural and necessary; the second is the extra warming from human emissions.
• Global warming vs ozone depletion: different problems with different causes. Do not mix them.
• Soil erosion vs desertification: erosion is loss of soil anywhere; desertification is land degradation in dry areas, and erosion is one part of it.
• Local vs global threats: noise and visual pollution are local; greenhouse gases are global; air and water pollution can be both.
• Renewable vs non-renewable resources: non-renewable resources are finite; renewable resources can still run out if used faster than they recover.
• Sustainable development vs conservation: sustainable development is the overall goal; conservation is one way to reach it.
• Threat to the environment vs threat to people: the syllabus asks for both, so say who is harmed.

Mini essay plan

“Economic development will always harm the environment.” To what extent do you agree? Refer to examples.

1. Introduction: define economic development and the four named threats.
2. Agree: oil in the Niger Delta caused spills, gas flaring and lost fishing income; UNEP found recovery could take up to 30 years.
3. Agree: overgrazing and overcultivation in the Sahel contribute to desertification; burning fossil fuels drives enhanced global warming worldwide.
4. Disagree: harm is not inevitable. Terracing and contour ploughing reduce soil erosion; filters and waste-water treatment cut pollution; renewable energy lowers emissions.
5. Disagree: development brings money for management, such as the Great Green Wall or clean-up agencies.
6. Judgement: development usually carries risk, but the size of the harm depends on management, laws and their enforcement. Harm is likely, not certain.

Quick self-test

1. State the four threats listed in the syllabus guidance.
2. State the four types of pollution the syllabus lists.
3. Define desertification.
4. Give two economic activities that add greenhouse gases.
5. Explain how terracing reduces soil erosion.
6. Explain eutrophication in one sentence.
7. Give one source and one effect of noise pollution.
8. State the Brundtland definition of sustainable development.
9. Explain why a renewable resource can still run out.
10. In a fictional village, 26 of 40 wells tested were polluted by oil. Calculate the percentage polluted.
11. Identify one threat from oil extraction in the Niger Delta that is local and one that is global.
12. Give two methods of resource conservation.

Answers

1. Soil erosion, desertification, enhanced global warming and pollution.
2. Water, air, noise and visual.
3. The degradation of land in arid and semi-arid areas so that it becomes more like a desert.
4. Any two: burning fossil fuels in power stations or vehicles; deforestation; cattle farming; rice growing; gas flaring.
5. Flat steps break the slope, slowing run-off so water soaks in instead of washing soil away.
6. Fertiliser or sewage nutrients make algae grow; when the algae die and decay, bacteria use up the oxygen and fish die.
7. Source: an airport, motorway, factory or quarry blasting. Effect: stress, poor sleep or disturbed wildlife.
8. Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
9. Because it is being used faster than it can recover, for example overfishing.
10. 26 ÷ 40 × 100 = 65%.
11. Local: oil spills killing fish and mangroves (or polluted drinking water). Global: gas flaring adding carbon dioxide to enhanced global warming.
12. Any two: reduce, reuse, recycle; energy efficiency; renewable energy; fishing quotas; replanting forests; water metering.

Where marks are usually lost

• Writing “global warming” with no reference to human emissions, so the answer does not show “enhanced”.
• Explaining global warming as a hole in the ozone layer.
• Listing threats with no economic activity as the cause, when the question asks how activities pose threats.
• Describing environmental damage but not the effect on people, or the reverse.
• Forgetting to say whether a threat is local or global when the question asks for both scales.
• Giving only “protect the environment” as a definition of sustainable development.
• Case study answers with no place names, dates or figures, or using a whole country with no named area.
• Describing management without judging how well it has worked.

Links

• Connect farming threats to the Food production revision notes.
• Connect pollution to the Industry revision notes.
• Review deforestation in Climate and natural vegetation.

Official syllabus

These notes follow the Cambridge IGCSE Geography (0460) syllabus for examination in 2025 and 2026, Version 2 (published November 2022), section 3.7 Environmental risks of economic development. Check the latest version on the Cambridge International website; your teacher will confirm anything the syllabus does not print.