Environmental risks of economic development

Cambridge IGCSE Geography 0460 · Paper 1 Geographical Themes · Theme 3 Economic development Syllabus: 2025 and 2026 Official syllabus point: 3.7

Read this before anything else. This subtopic is examined up to and including the November 2026 series and then stops. If you are sitting 0460 in 2027 or later, close this page. The 2027 syllabus has no topic called environmental risks of economic development. It handles environmental management differently, splitting the material across a new physical topic on climate change and a human topic on resource provision, and the case study requirement disappears. Section 2 below sets out exactly where each piece goes, so you can find the right page if you are in the 2027 cohort.

If you are sitting the June 2026 or November 2026 papers, this topic is live, it is worth studying, and it has supplied the 7 mark case study question on 14 of the 35 Paper 1 variants in our 2020 to 2024 question bank. That is roughly two papers in five.

1. What the syllabus actually says

Theme 3 is the third of the three sections on Paper 1. You answer one question from each section, each worth 25 marks, and Theme 3 questions are numbered 5 and 6. The mark pattern inside a question is fixed: part (a) is worth 1, 2, 3 and 4 marks, part (b) is worth 3 and 5 marks, and part (c) is the 7 mark case study question. That is 25.

Subtopic 3.7 prints three things candidates should be able to do:

The further guidance column names the threats you are expected to know:

Threats to the natural environment (including soil erosion, desertification, enhanced global warming and pollution [water, air, noise, visual]).

Note the word including. That list is not a closed list, and mark schemes routinely credit deforestation, loss of habitat, extinction of species, damage to food chains, acid rain and coral bleaching alongside the four named items.

There is one Case Study required for 3.7:

An area where economic development is taking place and causing the environment to be at risk.

Read the word area carefully. It is doing real work, and section 3 explains why.

2. What survives into the 2027 syllabus, and what does not

This matters if you are teaching both cohorts, or if you are a 2026 candidate wondering how much of this is wasted effort. The honest answer is that most of the content survives somewhere, but the topic does not, and the framing changes completely: in 2026 these are risks caused by economic development, and in 2027 they are challenges of supplying food, energy and water, or a physical topic in their own right.

The short version. If you are a 2027 candidate, the global warming and desertification work carries over almost intact, the sustainable development work carries over, and the air, noise and visual pollution work does not.

3. What the exam actually asks, and the place rule that is stricter than usual

Across the 2020 to 2024 papers, the 3.7 seven mark question comes in only two shapes, and they alternate.

Shape one: how an economic activity threatens the environment.

• "For a named area you have studied, describe how economic development is damaging the natural environment." (Oct/Nov 2020)
• "For a named area you have studied, explain how economic activity is causing the local natural environment to be at risk." (May/June 2021)
• "For a named area you have studied, explain how an economic activity may damage the local natural environment." (May/June 2022)
• "Name and locate an economic activity you have studied. Explain how this economic activity threatens the natural environment." (Oct/Nov 2023)

Shape two: how those risks are managed.

• "For a named area you have studied, explain how economic activity is managed to reduce the risks to the natural environment." (May/June 2021)
• "For a named area you have studied, explain how an economic activity is managed sustainably." (Feb/March 2022)
• "For an area you have studied, explain how the risks to the local natural environment of a named economic activity are being managed." (Oct/Nov 2022)
• "Explain how a named economic activity in an area you have studied is managed to reduce risks to the natural environment." (May/June 2024)

Alongside these sit the standalone questions on global warming and on desertification, which do not use the case study wording at all and instead say "you should refer to named areas affected".

The place rule, and why one named place is not always enough

Every 7 mark question in this topic caps you if you do not name a place, but 3.7 prints two extra restrictions that most other topics do not, and both are easy to fall foul of.

Restriction one: a whole country is usually too big. Two mark schemes four years apart say so explicitly.

• Oct/Nov 2020, on describing how economic development is damaging the natural environment: "Countries are Max 5 unless they are very small."
• May/June 2024, on managing an economic activity to reduce risks: "Named location must be smaller than a country and a named economic activity."

So "Brazil" or "China" will hold you at Level 2. You need a region, a river basin, a delta, a mining district, a national park, a stretch of coast, a named city or a named industrial zone, and you need to say which economic activity you mean.

Restriction two: some questions demand two places, not one. The Feb/March 2023 desertification question prints the stricter version of the cap:

MAX 5 if no references to places where desertification is occurring.
MAX 6 if only one reference to a place where desertification is occurring.

That double cap is not a one off. The same wording appears on the global warming impacts questions of Oct/Nov 2021 and May/June 2022, and the Oct/Nov 2023 version goes further still and states plainly: "Must refer to two place references."

So on a desertification or global warming question, one named place gets you 6 out of 7 at best. Learn two places for each. Section 12 gives you a bank of them.

Restriction three, which runs the other way. On the Oct/Nov 2024 question "Explain how economic activities can increase global warming. Refer to named examples", the mark scheme says: "Named examples are e.g. factories, transportation, deforestation, grazing, rice paddies, fracking, etc. and not specific places." Here a place name earns nothing. The examiner wants named activities. Read the stem, not the habit.

Exam trap: the Oct/Nov 2020 mark scheme adds a command word warning that costs candidates marks every year. On a describe question it says "Any development should be describing damage to the natural environment not explaining the causes of it." If the stem says describe the damage, do not spend half the answer explaining why the logging happens.

4. Economic activities and the threats they pose

This is the heart of the topic. Mark schemes for shape one questions accept any economic activity at any scale, so learn the mechanism rather than a list. The pattern the examiner wants is always the same three steps: name the activity, name the threat, and say how the one produces the other.

1. factory discharges warm effluent into the river
2. water temperature rises
3. warm water holds less dissolved oxygen
4. fish and invertebrates suffocate
5. the food chain above them collapses
6. the fishing families who ate and sold those fish lose both their food and their income.

Marks note: the mark schemes reserve development marks for exactly that kind of second and third step. "Factories cause pollution" is Level 1. "Factories discharge chemicals into the river which kill the fish" is Level 2. Adding the name of the factory, the river and the town gets you Level 3.

5. Pollution: the four types the syllabus names

The further guidance lists pollution in brackets as water, air, noise, visual. Learn all four. A related Oct/Nov 2021 mark scheme on types of pollution states "1 L2 max for each type of pollution", which means breadth is rewarded and depth on one type alone is capped. Write about several types, not one in enormous detail.

Water pollution

Causes from economic activity: industrial effluent and heavy metals; untreated sewage from settlements built for workers; fertiliser and pesticide runoff from commercial farming; oil spills from extraction, pipelines and shipping; hot water returned from power station cooling; mine tailings and toxic leachate; plastic and solid waste.

Effects the mark schemes credit, from the Feb/March 2023 and Oct/Nov 2022 papers:

• poisonous to aquatic life, harms or kills fish, animals and vegetation;
• decreases oxygen in the water;
• eutrophication;
• reduced biodiversity and extinction of species;
• reduction of food supplies for predators, and concentration of pollutants higher up the food chain;
• loss of habitat;
• bleaching or damage to coral reefs;
• decline of the fishing industry, poisonous seafood harming people, loss of tourism, smells.

1. fertiliser is applied to a cotton field
2. heavy rain washes nitrate and phosphate into the river
3. nutrient levels rise
4. algae bloom across the surface
5. light is blocked from plants below
6. the algae die and bacteria decompose them
7. oxygen is stripped from the water
8. fish suffocate and die.

Exam trap: the Feb/March 2023 mark scheme prints "Too vague: Damages ecosystems". Naming the ecosystem effect precisely, such as "disrupts the food chain because the small fish that the herons eat die first", is what earns the mark.

Air pollution

Causes: burning fossil fuels in power stations, factories, vehicles and homes; burning of forest and crop residue; dust from quarrying, mining and construction; industrial chimneys.

The May/June 2024 mark scheme is unusually generous about effects, and worth learning because it credits both human health and the wider environment:

• kills people and animals; breathing difficulties, asthma, emphysema, lung cancer and tuberculosis; heart problems; birth defects; irritation of skin and eyes;
• reduces visibility and causes smog;
• acid rain and ocean acidification, which erodes stonework on buildings and statues;
• destruction of the ozone layer, increasing ultraviolet rays and skin cancer;
• global warming and its consequences, including rising sea levels and coral bleaching;
• kills vegetation and restricts crop growth;
• affects food chains, reduces biodiversity, destroys ecosystems;
• restricts tourism, closes schools and businesses.

The same paper printed that carbon monoxide accounted for 38 per cent of air pollution in the USA on its own resource, so figures of that kind do appear and can be quoted straight from the insert.

Noise pollution

Underrated and easy marks. Sources: construction and blasting; factory machinery; road, rail and air traffic; mining equipment; tourist boats, jet skis and nightlife.

Effects: sleep disturbance and stress; hearing damage for workers; disturbance of wildlife and breeding behaviour; loss of amenity for residents; underwater noise disrupting marine mammals. Mark schemes credit "construction noise" and "noise" as free standing points in dam, quarry and shopping mall questions.

Visual pollution

Also underrated, and it appears in mark schemes more often than candidates expect. It means the spoiling of the appearance of a landscape.

Sources credited in past mark schemes: spoil and waste heaps from mining; power stations; quarries altering the shape of the landscape; hotel and shopping developments; advertising hoardings; litter; derelict buildings; overhead cables and wind turbines.

Effects: loss of the scenic quality that attracted tourists; falling property values; loss of enjoyment for residents; damage to a place's reputation. Mark schemes accept both "visual pollution" and the plainer "spoils the scenery" or "eyesore".

Exam trap: candidates commonly write only about air and water pollution. The syllabus names four types and mark schemes cap development on any one of them, so a paragraph on noise and a sentence on visual pollution are among the cheapest marks in the topic.

6. Enhanced global warming

The syllabus says enhanced global warming, and the word matters. The natural greenhouse effect keeps the Earth warm enough to live on. The enhanced greenhouse effect is the extra warming caused by human activity adding greenhouse gases beyond the natural level.

The mechanism, which is worth up to 5 marks on its own

Mark schemes award marks step by step for this chain, so write it as a chain and not as a single sentence.

1. economic activity burns fossil fuels
2. carbon dioxide and other greenhouse gases are released
3. they build up and form a layer or blanket in the atmosphere
4. short wave rays from the Sun pass through the layer
5. the rays strike the Earth's surface and are radiated back as long wave heat
6. the layer traps that heat and reflects it back instead of letting it escape into space
7. global temperatures rise.

Marks note: the Feb/March 2023 mark scheme prints "Too vague: Enhances greenhouse effect" as a non credit answer. Naming the process is not the same as describing it. Every arrow in the chain above is a separate mark, and a 4 mark question wants four of them.

Greenhouse gases and the activities that release them

Deforestation appears twice, and mark schemes credit both halves separately: burning the trees releases carbon dioxide, and removing the trees means fewer plants left to absorb it. The mark scheme calls the second one "loss of carbon sinks".

Impacts of global warming

Three different mark schemes between 2021 and 2023 converge on the same content list, which makes it a safe one to learn:

On the natural environment

• melting of ice caps and glaciers;
• rising sea levels and flooding of coastal lowlands and low lying islands;
• warming oceans and bleaching of coral;
• changing rainfall patterns, more drought, more desertification;
• more frequent and more severe tropical storms;
• wildfires;
• loss of habitat, impacts on species, biodiversity and food chains.

On people

• difficulty producing food, crop failure, starvation;
• lack of water supplies;
• flooding of homes and forced migration;
• spread of tropical diseases into new areas;
• heat stroke and heat related death;
• conflict over land and water.

Positive impacts are credited. The Oct/Nov 2023 mark scheme notes explicitly: "Accept positive impacts e.g. growth/ripening of vines in temperate countries etc." Longer growing seasons at high latitudes and new shipping routes through a less frozen Arctic are the standard examples. An answer that acknowledges one is stronger than one that does not.

Evidence that it is happening, which is what a "state three pieces of evidence" question wants, and which the May/June 2022 insert supplied directly: rising global mean surface temperature; each recent decade warmer than the one before; record national temperatures; retreat of glaciers and sea ice; rising sea level. That paper's own resource quoted a rise of 0.18 °C per decade and stated that 19 of the 20 hottest years had occurred since 2000.

7. Soil erosion and desertification as risks of economic development

Both are covered at length in the resource provision notes, where they belong to the food supply syllabus points. This section deliberately does not repeat the causes table or the management table you will find there. What follows is only the part that 3.7 asks for and 10 does not: the link from an economic activity to the damage, and the place rule.

Soil erosion is the removal of topsoil by wind or by running water faster than it can be replaced.

Desertification is the process by which land in semi arid areas becomes desert like, losing its vegetation, its soil fertility and its ability to support farming.

The 3.7 angle is that both are usually caused by an economic activity, and the exam wants that link stated:

1. a plantation clears forest for export crops
2. tree roots no longer hold the soil and there is no canopy to break the rain
3. raindrops strike bare ground and runoff increases
4. topsoil is stripped and gullies form
5. yields fall and the farmer clears a new patch of forest
6. the cycle repeats and the land degrades further.

Marks note: this is the topic where the double cap bites hardest. The Feb/March 2023 desertification question printed "MAX 5 if no references to places where desertification is occurring" and "MAX 6 if only one reference to a place where desertification is occurring". One named place holds you at 6 out of 7. Name two, for example the Sahel belt on the southern margin of the Sahara and the margins of the Gobi in northern China.

For the full causes, effects and management of desertification and soil erosion, including terracing, contour ploughing, stone bunds, shelter belts and the evaluation, go to the resource provision notes.

8. Local and global: the scale distinction the syllabus prints

The syllabus statement says threats to the natural environment and people "locally and globally". That is a deliberate instruction, and mark schemes note "Accept local or global impacts" and, on the deforestation question, "Impacts must be global natural environment" when the stem says global. Sorting your answer by scale is the fastest way to show range.

Exam trap: a question that says "the global natural environment" will not reward local impacts. The May/June 2021 deforestation mark scheme is blunt about it: "Impacts must be global natural environment". If the stem says global, write about carbon dioxide, temperature, ice, sea level and the places that lose out, not about the local villagers.

9. The need for sustainable development and management

The definition itself belongs to Theme 3's development subtopic and is set out in full in the development notes, so it is given here once and not expanded.

Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

What 3.7 asks for is different and narrower: why it is needed, and what sustainable management of an economic activity looks like. That is the shape of the Feb/March 2022 question, "explain how an economic activity is managed sustainably".

Why it is needed

• Resources are finite. Fossil fuels, minerals and old growth forest do not come back on a human timescale. Once used, they are gone for everyone who comes later.
• Damage is often irreversible. A species that is extinct cannot be restored. Topsoil takes centuries to form and can be lost in a season. Groundwater contaminated with heavy metals stays contaminated.
• The economy depends on the environment it is damaging. Fishing collapses when the fish are gone. Tourism collapses when the reef bleaches or the beach is fouled. Farming collapses when the soil blows away. Destroying the resource base destroys the industry.
• The costs fall on people who did not benefit. The factory is profitable in one place while the acid rain, the sea level rise and the polluted river arrive somewhere else, often in a poorer country.
• Populations and demand are still rising, so the same practices applied to more people cause more damage each year.

What sustainable management of an activity looks like

The test is the same one used for sustainable development generally, applied to a single activity. A scheme is sustainable if it passes all three:

• Economically: it earns enough to keep going without permanent outside subsidy.
• Socially: it improves the quality of life of local people and involves them in the decisions.
• Environmentally: it does not degrade the resource base it depends on.

1. a coastal resort limits hotel building, treats its sewage before discharge and charges a small reef fee
2. the reef stays alive and the water stays clean
3. tourists keep coming and keep paying
4. the fee funds the treatment plant and the wardens
5. local people keep the jobs and the fishery
6. the activity can continue indefinitely, which is what sustainable means.

Marks note: the Feb/March 2022 mark scheme accepts management at any scale, and gives fencing a vulnerable area of sand dunes to stop trampling as its small scale example and the creation of a National Park as its large scale one. Do not assume only big schemes count.

10. The importance of resource conservation

Resource conservation means using resources carefully so that they last longer, are not exhausted, and remain available to future users.

The distinction to start from:

• Non renewable resources exist in a fixed quantity and are used up: coal, oil, natural gas, metal ores, and groundwater in an aquifer that does not refill.
• Renewable resources are replaced naturally, but only if the rate of use stays below the rate of replacement: forests, fish stocks, soil and fresh water. Used too fast, a renewable resource behaves exactly like a non renewable one. Overfishing and deforestation are what that looks like.

Why conservation matters

• It extends the life of a finite resource, buying time to develop alternatives.
• It reduces the environmental damage of extraction, since less mining, drilling and logging means less habitat loss, less pollution and less spoil.
• It is usually cheaper than new supply. Insulating a house costs far less than building the power station to heat it. This is the single most useful judgement in an evaluation.
• It reduces waste going to landfill and the pollution that comes with it.
• It protects the resource base that a country's economy depends on, which is the point at which conservation and sustainable development become the same argument.

How it is done

Marks note: conservation questions are usually short recall or resource based, and the answers are simple. Do not overcomplicate them. The value of this section is that "conservation measures" and "education about recycling and water conservation" are creditable points inside longer water, energy and management answers as well.

11. Detailed case study: oil extraction in the Niger Delta, Nigeria

The syllabus requires one case study of an area where economic development is taking place and causing the environment to be at risk. Remember the mark scheme rule: the named location must be smaller than a country, and you must name the economic activity. "Nigeria" is capped at 5 marks. "Oil extraction in the Niger Delta" is not.

The area and the activity

The Niger Delta is the delta of the River Niger on the Atlantic coast of southern Nigeria, in West Africa. It covers roughly 70,000 square kilometres and contains the largest area of mangrove forest in Africa, along with freshwater swamp forest, creeks and lowland rainforest. Several million people live in it, most of them dependent on fishing and subsistence farming.

The economic activity is onshore crude oil and natural gas extraction. Oil was discovered at Oloibiri in 1956 and commercial production began at the end of that decade. Oil has since supplied the large majority of Nigeria's export earnings, and the delta is criss crossed with wellheads, flow stations and pipelines, many of them decades old. Ogoniland, in Rivers State, is the most closely studied part of it.

How the activity puts the environment at risk

Water pollution. Crude oil escapes from corroded pipelines, from equipment failure, from operational discharges and from illegal tapping and crude refining. Oil spreads across creeks, farmland and mangrove roots. Mangroves die where oil coats the aerial roots through which they breathe. Fish and shellfish are killed or contaminated. Drinking water wells in some communities have been found to be contaminated with hydrocarbons including benzene.

Air pollution and enhanced global warming. Natural gas produced alongside the oil has for decades been burned off at the wellhead in gas flares rather than captured, some of them burning continuously for years within sight of villages. Flaring releases carbon dioxide, methane and soot, contributes directly to enhanced global warming, produces acid rain locally, and causes the black soot deposits that residents report on roofs and crops. Nigeria has formally prohibited routine flaring since the 1980s, yet it has continued.

Loss of habitat and biodiversity. Mangrove is cleared for pipelines, access canals and terminals, and killed by oil. Mangrove is a nursery habitat, so its loss removes the breeding ground of the fish that the fishery depends on. Canals cut through the delta let salt water into freshwater swamp, changing the ecosystem beyond the immediate site.

Soil contamination and loss of farmland. Oil soaks into soil and, in the worst affected sites, has been found metres below the surface. Contaminated land will not grow crops.

Noise and visual pollution. Flares burn day and night, lighting the sky and generating constant roar. Flow stations, pipelines carried above ground and terminals dominate what was mangrove and farmland.

Threats to people. Fishing and farming, the two livelihoods of the delta, are both undermined by the pollution. Loss of income and of a local protein source follows. Communities report respiratory illness and skin problems. Contaminated drinking water carries a direct health risk. The combination has produced long running conflict between communities, companies and the state, and outward migration to cities.

1. old pipelines corrode and are also tapped illegally
2. crude oil escapes into creeks and onto farmland
3. oil coats mangrove roots and the trees suffocate and die
4. the nursery habitat for fish is destroyed and shellfish are contaminated
5. catches collapse and crops fail on oiled soil
6. fishing and farming families lose both their food and their income
7. young people migrate out and conflict over compensation intensifies.

How the risks are being managed, and how well

• The UNEP assessment of Ogoniland, published in 2011, was the scientific baseline. It found contamination far more widespread and far deeper than expected, recommended an initial capital injection of about US$1 billion into an Ogoniland Environmental Restoration Fund, and estimated that a full clean up could take 25 to 30 years. That timescale is itself the strongest evaluative point available: the damage of a few decades takes a generation to undo.
• The Hydrocarbon Pollution Remediation Project (HYPREP) was established by the Nigerian government in 2016 to carry out the UNEP recommendations. Progress has been widely criticised as slow, and clean up of many sites had not been completed years after it began.
• Litigation and compensation. After two large spills at Bodo in 2008, Shell agreed in January 2015 to a settlement of about £55 million with the Bodo community, most of it paid directly to individuals. Legal action has proved more effective than regulation at forcing payment, but it deals with damage after the fact rather than preventing it.
• Pipeline replacement and monitoring. Replacing corroded pipelines, installing leak detection and increasing surveillance address the largest single cause of spills, but the network is enormous and much of it is remote.
• Ending routine gas flaring. Capturing associated gas and piping it for use or export removes the flares and turns a pollutant into a product. Progress has been real but slower than successive deadlines required.
• Remediation and replanting. Contaminated soil is excavated or treated and mangrove is replanted. Mangrove takes many years to re establish, and replanting fails where oil remains in the sediment.
• Community involvement and alternative livelihoods. Training and employing local people in the clean up, and funding fish farming and other livelihoods, addresses the social pillar. Schemes that exclude the affected communities have repeatedly stalled.

How to write the evaluation. The honest judgement is that the technical solutions are known and the constraint is enforcement and money, not knowledge. Litigation has extracted compensation but only after the harm. Regulation has existed for decades without stopping flaring. The clean up that is scientifically necessary is measured in decades and billions of dollars, which is why the strongest answer is that preventing contamination through pipeline replacement and gas capture is far cheaper than remediating it afterwards, and that no scheme will hold unless the communities that live with the pollution are employed by and benefit from the clean up.

Why this case study works for both question shapes. It answers "how is economic activity putting the local natural environment at risk" and "how are those risks being managed" from the same set of facts. That is worth checking before you commit to any case study of your own.

12. Places to name, so you never hit the MAX 6 cap

The global warming and desertification questions need two named places, and they are places where the impact is felt, not where you live. Learn a short list and use two every time.

Global warming: places affected

Desertification: places where it is occurring

• The Sahel, the semi arid belt running across Africa on the southern margin of the Sahara, through countries including Mali, Niger, Chad and Sudan.
• Northern China, on the margins of the Gobi desert, where dust storms reach Beijing.
• North east Brazil, the semi arid sertão.
• The Aral Sea basin, in Central Asia, where the diversion of rivers for irrigated cotton has left salt flats and dust storms behind a shrinking sea.

Exam trap: naming two countries on the same continent affected in the same way is weaker than naming two places affected in different ways. "Greenland is losing ice, and the meltwater raises sea level in low lying places such as the Maldives" links them, which is what a Level 3 answer does.

13. Fieldwork links for Paper 4

Environmental risk is one of the easiest topics to link to fieldwork, and Paper 4 tests it directly through environmental quality work.

Hypotheses that appear

• Does environmental quality decline closer to the industrial area?
• Does environmental quality increase with distance from the village or the city centre?
• Is noise pollution greater along the main road than in the residential streets?
• Does litter increase at the most visited sites in the National Park?

Methods to be able to describe

• Environmental quality survey using a bi polar scale. Score each site on several criteria, for example litter, noise, air quality, vandalism, greenery and building condition, from a negative extreme to a positive extreme, then total the scores for each site. Past mark schemes use scales that run into negative totals, so be ready to plot negative values.
• Litter count. Tally items of litter within a fixed quadrat or a fixed length of street at each site, so the sites are comparable.
• Traffic and pedestrian count. Tally vehicles by type for a fixed period at each site, for example ten minutes, repeated at the same time of day.
• Noise measurement. Use a sound meter or phone app at each site for a fixed period, recording the average and the peak.
• Air quality. Sticky tape or petroleum jelly on card left for a fixed time at each site, then count the particles trapped.
• Field sketches and annotated photographs, which record visual pollution far better than a number can.
• Questionnaires and interviews with residents and workers about the problems they experience, which capture the effect on people rather than only on the environment.

Reliability points that earn marks

• Agree in advance what each descriptor on the bi polar scale means, or two students will score the same street differently.
• Have several students score independently and take an average, or compare and look for anomalies. The bias of a single observer is the main weakness of any quality survey, and the mark schemes reward saying so.
• Survey every site at the same time of day and on the same day of the week, because traffic, noise and litter all vary by hour.
• Run a pilot survey first.
• Increase the number of sites to make the pattern along the transect clearer.

14. Common exam mistakes

• Naming a whole country as the area. Two separate mark schemes say the location must be smaller than a country. "China" is capped at 5. "The Pearl River Delta manufacturing zone" is not.
• Naming only one place on a global warming or desertification question. The double cap holds you at 6 out of 7. Name two.
• Naming a place on the Oct/Nov 2024 style question that asks for named examples of economic activities. There the mark scheme says place names do not count, and it wants factories, transport, deforestation, grazing, rice paddies or fracking.
• Explaining causes when the stem says describe the damage. The Oct/Nov 2020 mark scheme warns about exactly this.
• Writing "damages the ecosystem" and stopping. The mark scheme prints that as too vague. Say which organism, and what happens to it.
• Writing "enhances the greenhouse effect" as the whole explanation. Also printed as too vague. Give the chain: gases build up, form a layer, the Sun's rays pass through, heat is trapped and cannot escape.
• Writing only about air and water pollution. The syllabus names four types and a related mark scheme caps development on each type, so noise and visual pollution are free marks that most candidates leave on the table.
• Writing only about the natural environment. The syllabus statement says "the natural environment and people", and the questions do too.
• Writing only about negative impacts of global warming. Mark schemes accept positive impacts such as longer growing seasons in temperate countries.
• Listing management methods without saying how each one works, or without any drawback, on a question that expects evaluation.
• Choosing a case study that only fits one of the two question shapes. Half the 3.7 case study questions ask about the risk and half ask about the management. Choose an area where you can do both.
• Confusing the natural greenhouse effect with the enhanced one. The natural effect is necessary for life. The enhanced one is the problem.

15. Quick revision

• Examined up to November 2026 only. In 2027 the content splits between Topic 5 Climate change, Topic 10 Resource provision, Topic 8 Development and river pollution in Topic 1. Air, noise and visual pollution disappear.
• Three content statements: threats from economic activity to environment and people, locally and globally; the need for sustainable development and management; the importance of resource conservation.
• Four named pollution types: water, air, noise, visual. Cover more than one.
• Named area for the case study must be smaller than a country, and you must name the economic activity.
• Global warming and desertification questions cap you at 6 out of 7 with only one named place. Use two.
• Global warming chain: fossil fuels burned → greenhouse gases released → form a layer → the Sun's rays pass through → heat radiated from the surface is trapped → temperatures rise.
• "Enhances the greenhouse effect" and "damages the ecosystem" are both printed as too vague. Give the mechanism.
• Impacts of global warming: melting ice, sea level rise, coastal flooding, coral bleaching, changing rainfall, drought, wildfires, food and water shortage, disease spread, migration. Positive impacts are credited.
• Eutrophication chain: fertiliser → runoff → nutrients rise → algal bloom → light blocked and algae decompose → oxygen stripped → fish die.
• Sustainable management passes three tests: economic, social and environmental. Fail one and it is not sustainable.
• Resource conservation: reduce, reuse, recycle, substitute, protect, regulate, price, educate. Conservation is usually cheaper than new supply.
• Case study: oil extraction in the Niger Delta, Nigeria. Spills, gas flaring, mangrove loss, contaminated water and soil, lost fishing and farming livelihoods. UNEP 2011 recommended about US$1 billion and estimated 25 to 30 years for clean up. Shell settled at Bodo for about £55 million in 2015.
• Paper 4 link: bi polar environmental quality survey, litter counts, traffic counts, noise readings. Agree the descriptors first and average across observers.

Not the topic you were looking for? Describe what you are stuck on in your own words and we will take you to the notes that answer it.