IGCSE Environmental Management Topic 1: Natural resources — Challenge Prep

1 · What the two papers actually pay for▶

Everything on the Topic 1 syllabus is already taught in the study guide. This page is not more content. It is about the gap between an answer that knows the material and an answer that scores — which in Environmental Management is almost always a gap in technique.

Where the marks actually are

0680 has two papers. Each is 1 hour 45 minutes, each is 80 marks, and each is worth 50% of the grade. They are not the same paper twice.

Paper	AO1 knowledge	AO2 application	AO3 analysis & evaluation	What it feels like
Paper 1 Principles of Environmental Management	55	30	15	Mostly recall and short explanation, building to one longer discuss question.
Paper 2 Environmental Management in Context	30	30	40	Source led. Every question set hangs off a chart, a table or a map, and you are marked on what you do with it.

The single most important number on this page

AO3 is 40 marks in every 100 on Paper 2. That is 32 marks of the 80, and it is the half of the course that cannot be revised by reading. It is four repeatable moves — quote figures, say what the data does not show, weigh both sides, land a judgement — and they are the same four moves whatever the source is about. That makes them the highest-value thing in this whole guide.

Why Topic 1 in particular rewards technique

Three features of this topic decide most of the marks, and none of them is about knowing more facts.

Feature of Topic 1	Where it appears	What it is worth
Five definitions given word for word	ore (1.2.1), finite resource (1.3.1), sustainable management of resources (1.3.2), permeability (1.1.3), fracking (1.6.1)	One mark each, sometimes two, and they are free if you have the exact wording. They are also one-mark losses if you paraphrase them into something vaguer.
Two ordered chains	the rock cycle (1.1.2) and the formation of fossil fuels (1.4.1)	Ordered chains are marked in order. Learning them as a list rather than a sequence is what loses the marks.
Five separate "discuss the benefits and limitations" objectives	1.2.6, 1.3.4, 1.4.4, 1.5.3, 1.6.2	More than any other topic on the syllabus. Each is a 6 to 8 mark question in waiting, and they are all marked to the same shape.

Five discuss objectives, one shape

1.2.6, 1.3.4, 1.4.4, 1.5.3 and 1.6.2 all begin with the same four words: discuss the benefits and limitations. Learn one answer shape and it fits all five. Section 2 of this guide is that shape. Getting it right is worth more than any single fact in Topic 1, because it is worth about 30 marks spread across the two papers.

Command words, and what each one pays for

Command	What the answer must contain	The commonest way to lose the mark
Define	The syllabus sentence, given back. Nothing else.	Adding a detail from somewhere else, such as the word profitably in the definition of an ore.
State / identify	A name, a figure or a letter. One line. From a source, the figure and its unit.	Explaining when you were not asked, or giving the number without the unit.
Describe	What happens, in order, in enough detail to be unambiguous. From a source: with figures.	Describing a source without quoting a single number, which caps the whole answer at 1 mark.
Explain	A mechanism, with a so, a because or a which means in it.	Naming the thing instead of saying how it works.
Calculate	The working written down, then the answer with its unit, to 3 significant figures unless told otherwise.	Doing it in your head. The method mark survives an arithmetic slip; nothing survives a blank page.
Suggest	A reasoned answer that is not in the textbook, built from the source in front of you. There is no single right answer — the marks are for the reasoning.	Writing a recall answer that ignores the source completely.
Discuss / evaluate / to what extent	Both sides, then a judgement with grounds.	Stopping before the judgement, or writing one side at four times the length of the other.

Checkpoint — how the papers pay

Three questions on where the marks live.

Score: 0 / 3

Question 1

Paper 2 is 80 marks. How many of them are AO3?

A 15

B 30

C 32

D 40

AO3 is 40% of Paper 2, and 40% of 80 is 32. The 40 in the syllabus table is a percentage, not a mark total, and reading it as a mark total is an easy slip. Either way it is the largest single objective on that paper, and it is the one you cannot revise by reading.

Question 2

Which of these would score nothing in a define an ore question?

A Rock containing minerals and metals

B Rock that contains minerals and metals in it

C Rock from which a metal can be extracted profitably

D Rock containing metals and minerals

The 0680 definition at 1.2.1 is simply rock containing minerals and metals. The profitability version is a real definition used elsewhere, which is exactly why it is tempting, but it is not this syllabus and it imports an economic idea that belongs at 1.2.3, where cost and profit appear as a factor in the decision to extract. A, B and D are the same sentence in different words and all score.

Question 3

A question says "Describe the trend shown in Fig. 2. [3]". What is the surest way to lose two of the three marks?

A Writing more than three sentences

B Describing the trend correctly but quoting no figures from the graph

C Using the word increase instead of rise

D Mentioning the units

A describe question on a source is marked for figures. "It goes up and then levels off" is a correct description of a great many graphs, which is the problem — it could have been written without looking. Quote a pair of values so the marker can see the comparison you are making. Quoting the units is a good thing, not a bad one.

2 · The discuss frame — five moves that fit all five objectives▶

Topic 1 asks you to discuss the benefits and limitations of something five separate times. It is the most repeated instruction on the whole syllabus, and it is always marked to the same shape. Learn the shape once.

Objective	Discuss the benefits and limitations of …
1.2.6	strategies for managing landscapes damaged by extracting rocks, ores and minerals
1.3.4	sustainable management strategies for rocks, ores and minerals
1.4.4	the energy resources listed in 1.4.2
1.5.3	strategies for the management of energy resources
1.6.2	fracking

The five moves

A discuss answer is not an essay and it is not an opinion. It is five moves in order, and each move is worth marks that the move before it cannot earn.

Move	What you write	Why it earns
1 · Benefit	A named benefit with a so or a because attached.	Half the mark scheme is this column. A benefit with no reason is a label.
2 · Limitation	A named limitation, also with a reason.	The other half. An answer with no limitations is capped however good it is.
3 · Who bears the cost	Name who gains and name who pays. They are rarely the same people.	This is where evaluation starts. It converts a list into an argument.
4 · Over what timescale	Say when the benefit arrives and how long the cost lasts.	Almost every Topic 1 decision is a short gain against a long cost, or the reverse.
5 · Judgement	State what the decision turns on. Not "it depends" — on what it depends.	The last 2 marks of a 6-mark question, and the ones most candidates leave on the table.

The two ways this question is thrown away

Imbalance. Four paragraphs against fracking and one line for it is not a discussion. Cambridge is neutral on every one of these five objectives and the mark scheme has two columns, so a one-sided answer is capped no matter how good the one side is.

Stopping early. The final marks are not for more content. They are for saying what the decision turns on. If your last sentence is "so there are advantages and disadvantages", you have written a refusal to judge, and a refusal to judge scores nothing.

Moves 3 and 4, applied to all five objectives

These two moves are what separate a grade 6 from a grade 8, and they are worth learning as a table because the pattern repeats.

Objective	Who gains	Who bears the cost	Timescale
1.2.6 land restoration	The community that gets usable land back, and future users of the site	The mining company, which pays before it sees any return, and often the taxpayer if the company has gone	The damage is done in years; a restored soil and a planted woodland take decades to become what they replaced
1.3.4 recycling, legislation, alternatives	Future generations, who still have the resource	Today’s consumers and producers, through higher prices, sorting effort and the cost of inspection	The cost is immediate and visible; the benefit is spread far into the future and is never felt as an event
1.4.4 energy resources	Everyone who uses the electricity, wherever they are	The people who live beside the dam, the wind farm, the mine or the power station	A hydro-electric dam or a nuclear station is a commitment of 40 to 60 years and its waste lasts longer still
1.5.3 insulation, efficiency, storage	The household or country that pays a smaller bill afterwards	Whoever pays the installation cost up front, which is why the poorest households benefit least	Payback times run from months to decades, and that number decides whether the measure happens at all
1.6.2 fracking	The nation, through tax revenue and security of supply	The local community and its farmers: water, traffic, noise, tremor risk	A shale well produces for a few years; contaminated groundwater and the carbon dioxide released last far longer

The sentence to have ready

"The benefit is national and short term; the cost is local and long term" — or the reverse. One sentence in that shape, filled in from the question in front of you, earns the judgement mark on any of the five objectives. It works because it does the two things a judgement has to do: it takes a position, and it says on what grounds.

Checkpoint — the discuss frame

Four questions on the shape of a discuss answer.

Score: 0 / 4

Question 1

A 6-mark discuss question. How is the mark scheme most likely to be split?

A 6 for content, 0 for a conclusion

B Up to 4 for benefits and limitations, up to 2 for a supported judgement

C 3 for benefits, 3 for limitations, nothing for a conclusion

D 2 for a definition, 4 for content

This is the standard levels-style split and it tells you how to spend your time: two points each way, then a real ending. Notice what it means — a seventh excellent benefit is worth nothing, while two sentences of judgement are worth a third of the question.

Question 2

Which of these is a judgement?

A There are arguments on both sides of fracking

B Overall, fracking has advantages and disadvantages

C The case is strongest where the gas replaces coal and weakest where it replaces investment in renewables, so it turns on what the gas is displacing

D In conclusion, fracking is a very important issue

Only C states what the decision turns on. A, B and D are all ways of declining to answer, and they are the three commonest final sentences in the whole subject. A judgement needs a position and the grounds for it; being interesting is not grounds.

Question 3

In a discuss question about land restoration after mining, which of these is a limitation rather than a benefit?

A Trees planted on the site bind the soil and begin to rebuild a habitat

B Restoration is expensive and is paid for long before any return is seen, so a company that has closed may never do it

C Replacing the overburden returns the ground to something near its original level

D The land can be used again for farming or recreation

B names a cost, says who bears it and says when — three of the five moves in one sentence. That is what a full-mark limitation looks like. The other three are all genuine benefits of restoration.

Question 4

Why does the syllabus list legislation and enforcement as two separate strategies at 1.3.3?

A They mean the same thing and the list is repetitive

B Because making a rule and making it happen are different things, and a law that is not enforced changes nothing

C Because enforcement only applies to recycling

D Because legislation is international and enforcement is national

Two entries in a syllabus list means two marks are available. Legislation is writing the rule; enforcement is inspection, monitoring, fines and withdrawing licences. The distinction is also a gift in any discuss question, because "this depends on being enforced, and enforcement costs money and needs inspectors" is a limitation you can attach to almost every management strategy in Topic 1.

3 · Three answers, one question — and then you write one▶

The most useful thing anyone can show you is the same question answered three ways. Below are two six-mark discuss questions, each answered at a weak, a middling and a strong level — and, more importantly, exactly which words moved the mark.

The question · 6 marks

Discuss the benefits and limitations of recycling metals as a strategy for the sustainable management of rocks, ores and minerals. [6]

Six marks on a discuss objective means, almost certainly, up to 4 for benefits and limitations with at least one of each, and up to 2 for a supported judgement. Work out the structure from the number in the brackets before you write a word: two points each way, then a real ending.

Weak answer2 of 6

Recycling metals is good because it saves the environment and stops us running out of metal. It is also cheaper. But some people do not bother to recycle. So recycling is a good thing and everyone should do it.

What it earned: 1 for avoiding resource depletion, and 1 for a limitation, if the marker is generous about "some people do not bother" standing for the accessibility and education point at 1.3.3(b).
Why the other four were lost: "saves the environment" names no mechanism and no part of the environment. "It is cheaper" for whom, and than what? And the last sentence is not a judgement — "everyone should do it" is an instruction, and an instruction with no grounds behind it earns nothing at all. There is not one so or because doing real work anywhere in the answer.

Middling answer4 of 6

Recycling metals means less ore has to be mined, so the finite reserves last longer and less land is disturbed by quarries and open pits. It also uses far less energy than extracting the metal from its ore, which reduces the carbon dioxide released. However, metals have to be collected and sorted before they can be recycled, and this needs collection systems and public education, which cost money. Also not all products are easy to take apart. So recycling has both advantages and disadvantages.

What it earned: 1 for reduced ore extraction with its consequence, 1 for the energy saving with its consequence, 1 for the collection and sorting cost, 1 for the difficulty of separating mixed products. Four solid marks and a properly balanced answer.
Why the last two were lost: the final sentence. "Both advantages and disadvantages" is a refusal to judge, and the judgement is worth 2 of the 6. Nothing else needed to change — this answer is one sentence away from full marks, and that sentence is shorter than the ones already there.

Strong answer6 of 6

Recycling metals means less ore is mined, so a finite reserve is drawn down more slowly and less land is cleared for pits and spoil heaps (1). It also needs a fraction of the energy that extracting the metal from its ore does — aluminium from scrap takes about a twentieth of the energy of aluminium from bauxite — so less fuel is burnt and less carbon dioxide is released (1). Against that, the metal has to be collected, sorted and transported first, which needs collection systems, public education and money (1), and many products mix metals with plastics and other materials, so separating them is difficult and some metal is lost at every cycle (1). Weighing the two: the costs of recycling fall now, on today’s councils and consumers, while the benefit — a reserve that has not been used up — falls on people who are not yet born and is never felt as an event (1). That is why recycling rates depend so heavily on how easy and how cheap it is made to be, which means the decision turns less on whether recycling is worthwhile and more on whether the system around it is built well enough for people to use (1).

Why it is full marks: the first four marks are the same four ideas the middling answer had. The last two come entirely from moves 3, 4 and 5 — who bears the cost, over what timescale, and what the decision turns on. Notice that the strong answer is not much longer, and that it does not contain a single extra fact. It contains an extra argument.

The one-sentence diagnosis

Weak answers stop at the opinion. Middling answers stop at the list. Strong answers reach the judgement. Before you put your pen down, ask: does my last sentence say what the decision turns on?

The same treatment on an energy question

The question · 6 marks

Discuss the benefits and limitations of hydro-electric power as an energy resource. [6]

This is 1.4.4 applied to one resource. The trap here is that HEP is renewable, which makes it very easy to write six marks of praise and no limitations at all.

Weak answer1 of 6

Hydro-electric power is renewable so it will never run out and it does not pollute. It is much better than coal. Countries should use it more.

What it earned: 1 for it being renewable, with the consequence that the resource is not used up.
Why the rest was lost: "does not pollute" is unqualified and, for a large reservoir, not quite true. "Better than coal" is a comparison with nothing behind it. And there is not one limitation in the answer, which caps it hard however many benefits were added — a discuss question with one column filled in cannot reach the top band.

Middling answer4 of 6

Hydro-electric power is renewable, so the water is replaced by the water cycle and the resource is not used up. It releases almost no carbon dioxide while it is generating, unlike a coal or gas station. It can also be turned up and down quickly to match demand, and the dam can store water and control floods. However, building a dam floods a large area of land, which destroys habitats and can force people to move. It also costs a great deal to build. Overall it has good points and bad points.

What it earned: 1 for renewable with its reason, 1 for low emissions during generation, 1 for flooding land with its consequences, 1 for the construction cost. The response is balanced and the mechanisms are real.
Why the last two were lost: the same ending as before. "Good points and bad points" is the sentence that costs a third of the marks. There is also a missed opportunity: the answer never says who is flooded out and who gets the electricity, which is the sharpest thing about a large dam.

Strong answer6 of 6

Hydro-electric power is renewable, because the water that drives the turbines is replaced by the water cycle, so unlike coal or uranium the fuel is not drawn down (1). Once built, it releases almost no carbon dioxide while generating, and output can be raised or lowered within minutes, so it is useful for balancing intermittent wind and solar (1). The limitations are large. A reservoir floods a wide area, so habitats are lost and communities are moved off land they farm (1), and the construction cost is very high and paid decades before the electricity is sold, which puts it out of reach of many of the countries with the best sites (1). What decides the case is who ends up on each side of the ledger: the electricity goes to cities that may be hundreds of kilometres away, while the flooded valley, the lost farmland and the changed river below the dam are borne entirely by the people who lived there (1). And the timescales do not match either — the disruption is immediate and permanent, while the low-carbon benefit accumulates slowly over the forty to sixty years the scheme runs, so hydro is strongest where the site displaces a lot of fossil generation and weakest where it displaces a lot of people (1).

Why it is full marks: the final sentence is the whole of the difference. It names what the decision turns on, in one clause each way, and it does it using the material already in the answer rather than new content. That is precisely what the last 2 marks are for. Notice also the qualifier while generating attached to the emissions claim — small, accurate, and the sort of thing that keeps a strong answer out of trouble.

Now you write one — the fading sequence

Three versions of the same task, with less given each time. Work each one before you open the model.

Worked in fullDiscuss the benefits and limitations of land restoration after opencast mining. [6]

Read the model, then read the note underneath about which sentences earned which marks.

The answer

Replacing the stored overburden and improving the soil returns the site to something near its original level and profile, so the land can be farmed, built on or used for recreation again instead of being lost (1). Tree planting and bioremediation go further: the trees bind the surface and begin to rebuild a habitat, while plants and micro-organisms break down or take up pollutants left in the ground, so the site stops being a source of contaminated drainage (1). Against that, restoration is expensive and the money is spent after the ore has been sold, so a company has every reason to delay it and, if it closes first, the public may end up paying (1). And what is rebuilt is not what was there: a replaced soil has lost its structure and its organisms, so the ecosystem that returns is simpler than the one that was removed (1). Weighing these, the gain is spread across the whole community and the cost falls on one company at the point when the site has stopped earning (1), and the timescales are badly matched — the damage takes a few years to do and the soil and the woodland take decades to come back, so restoration works best when it is required and funded before extraction begins rather than promised for afterwards (1).

Why it scores 6 and not 4

The first four marks are two benefits and two limitations, each with a so. The last two are moves 3, 4 and 5 — who bears the cost, over what timescale, and what the decision turns on. The final clause, required and funded before extraction begins, is the judgement: it is a position, and the rest of the paragraph is the grounds for it.

What a weak version looks like

"Restoration is good because it makes the land nice again, but it costs a lot of money. So it has advantages and disadvantages." That is 2 marks. Both halves are real points; neither has a mechanism, and the ending is a refusal to judge.

Two benefits with reasons, two limitations with reasons, then who pays, over what timescale, and what it turns on.

Fading step 1 — the judgement is blankDiscuss the benefits and limitations of increasing the efficiency of extraction as a sustainable management strategy. [6]

The four content marks are written for you. You write the judgement — moves 3, 4 and 5, which is the last 2 marks.

Given: Extracting a higher proportion of the metal from each tonne of ore means more metal is obtained from the same amount of rock, so the deposit lasts longer and less new land has to be opened up (1). It also means less metal is thrown away in the waste, so the spoil heaps are smaller and contain less that could leach out (1). However, the improved processes generally need more energy and more water per tonne of rock, so part of the environmental saving is given back (1), and the new plant is expensive, so it is worth installing only where the metal price is high enough to pay for it (1).

You write: Weighing these, the gain falls on while the cost falls on , and over time , so the decision turns on .

Model judgement

Weighing these, the gain is shared — a deposit that lasts longer benefits the company, the workers and everyone who needs the metal later — while the cost is concentrated on the company, which has to pay for the new plant up front, and on whoever supplies the extra energy and water (1). Over time the balance shifts: the plant is a one-off cost and the saving continues for as long as the mine runs, but the extra energy is burnt every single day, so the strategy only pays environmentally if the electricity it uses is low carbon. The decision therefore turns on the metal price and on where the extra energy comes from, rather than on whether higher efficiency is a good idea in itself (1).

Marking your own

Did you name two different groups in the first clause? Did your timescale sentence say something that was not already in the content marks? And does your last clause finish the sentence "it turns on…" with a thing rather than with a shrug? If any of the three is missing, that is the mark.

Gain shared and lasting, cost concentrated and up front, and it turns on the metal price and the carbon intensity of the energy.

Fading step 2 — you write all of itDiscuss the benefits and limitations of ground source heat pumps as a way of managing energy resources. [6]

Nothing is given. Six marks means two benefits, two limitations, and a judgement worth 2. Remember what a heat pump actually does — the syllabus word at 1.5.2(c) is transfer, and getting that right is worth a mark on its own.

Model answer

A ground source heat pump transfers heat from the ground into a building rather than generating heat, so it delivers several units of heat for every unit of electricity it consumes and a house needs far less energy to stay warm (1). Because the ground a few metres down stays at much the same temperature all year, it works as well in winter as in summer, unlike an air source pump whose efficiency falls as the outside air gets colder (1). Against that, installation means digging trenches or drilling a borehole, so it costs a great deal up front and needs land, which rules it out for most flats and terraced houses (1). And it runs on electricity, so how clean it is depends entirely on how that electricity was generated — on a coal-heavy grid the emissions are simply moved from the house to the power station (1). Weighing these, the benefit goes to whoever occupies the building for the next twenty years, while the cost falls on whoever pays for the installation today, and those are often not the same person, which is why heat pumps spread fastest in owner-occupied homes and slowest in rented ones (1). So the decision turns less on the technology, which works, than on who can find the capital and on how quickly the grid is decarbonising (1).

The trap here

If you wrote that the pump "makes heat from the ground" or "generates energy", that is the mark gone. A heat pump moves heat that already exists. That is why it sits in 1.5, the conservation and management of energy, and not in 1.4 with the energy resources — it is not a resource at all.

Transfers, does not generate. Efficient and steady all year, but expensive, needs land, and only as clean as the grid.

Checkpoint — reading your own answer

Three questions on self-marking a discuss.

Score: 0 / 3

Question 1

The middling recycling answer scored 4 of 6. What was the cheapest available upgrade?

A Adding a third benefit

B Replacing the last sentence with a judgement that says who bears the cost and when

C Writing more about sorting and collection

D Defining recycling at the start

One sentence, two marks, and it is shorter than the sentences already in the answer. A third benefit is worth nothing, because the content marks were already capped at 4. This is the single highest-value habit in the subject: when you have two points each way, stop adding and start weighing.

Question 2

Which ending would earn the judgement marks on a fracking question?

A So fracking should be banned

B So fracking is both good and bad for the environment

C So it depends on the situation

D So the case is strongest where the gas displaces coal and weakest where it displaces investment in renewables

D takes a position and gives the grounds for it in the same sentence. A is an opinion with no support — and it would score no better if it said "should be allowed". B and C are the two standard ways of not answering; "it depends" only earns anything once you say on what.

Question 3

A student writes four paragraphs on the harm done by mining and two lines on its benefits. What happens?

A Full marks, because the four paragraphs are correct

B The answer is capped, because a discuss question is marked on two columns and one is nearly empty

C Marks are deducted for the extra length

D It depends on whether the student is right

The mark scheme has two columns and the top band needs both. Nothing is deducted for length — the problem is that the fourth paragraph of harm cannot be credited once the benefits column is capped, so the time spent on it bought nothing. Balance is not politeness; it is where the marks are.

4 · The AO3 toolkit — working from a source▶

AO3 is 40 marks in every 100 on Paper 2 — 32 of the 80. It is also the most trainable thing on the whole syllabus, because it is five repeatable moves rather than a body of knowledge. The moves are the same whether the source is about copper, coal or a river.

Demonstration source

Table 1 — two ways of supplying the same 500 GWh per year to region Z

Two schemes have been proposed to supply the same amount of electricity to the same region. Everything below is per scheme, not per year, unless the row says otherwise.

	Scheme A — hydro-electric dam	Scheme B — wind farm
Capital cost / $ million	420	300
Land flooded or occupied / hectares	3800	950
People moved off the land	1200	0
Output available on demand	yes	no
Expected working life / years	60	25

Table 1. Constructed for practice, not figures from a named scheme, but the shape of the comparison — a large, long-lived, high-impact scheme against a smaller, shorter-lived, intermittent one — is typical of a real choice.

Move 1 — read the headings and the units before you read the question

Two rows here are traps for anyone who does not. Capital cost is the cost of building, not of running. Land flooded or occupied covers two different kinds of loss under one heading. And every figure is per scheme, so nothing in the table is comparable until you have thought about the last row.

Move 2 — quote figures, and quote both ends

"The dam costs more" is a description that could have been written without the table. "The dam costs $420 million against the wind farm’s $300 million" is worth a mark, because a marker can see which two numbers you compared.

The calculation that flips the answer

Divide the capital cost by the working life. The dam is $420 m ÷ 60 years = $7.0 million per year of life. The wind farm is $300 m ÷ 25 years = $12.0 million per year of life. So the scheme that looked cheaper is the more expensive of the two once you account for how long it lasts. A single division turned the obvious reading of the table upside down, and that is exactly the kind of thing AO3 marks are for.

Move 3 — say what the data does not show

This is the move almost nobody makes, and it is usually a whole mark on its own. The question to ask is: what would I still need to know before I signed this off? Table 1 does not tell you:

the running and maintenance costs, or what it costs to take either scheme down at the end
what happens to the 1200 people who are moved, or whether they are compensated
whether the wind farm needs backup capacity for the times it produces nothing — the table says output is not available on demand, but not what fills the gap
what the land was being used for before. 950 hectares of poor upland and 3800 hectares of farmland are not the same loss, and a wind farm leaves most of its 950 hectares still farmable between the turbines
anything about the river below the dam, or about the birds and the noise at the wind farm

Do not answer with something the source does show

"It does not tell us how much land the dam floods" scores nothing, because it does: 3800 hectares. Read the row headings once more before you write this answer — the mark is for spotting a real gap, not for saying the source is incomplete in general.

Move 4 — weigh both sides

Weighing is not listing. A list says the dam is more expensive and floods more land, and the wind farm is intermittent and shorter lived. Weighing puts a number against a number: the dam occupies 4 times as much land as the wind farm, but it lasts 2.4 times as long and it delivers when it is asked to. Now the two columns are actually being compared.

Move 5 — land a judgement, and say on what grounds

Finish with what the decision turns on. For Table 1 that might be: the choice turns on whether the region can accept intermittent supply, because if it cannot then the wind farm needs backup and its real cost is not the $300 million in the table; and it turns on what the 3800 hectares are worth to the 1200 people living on them, which the table does not say. Both halves of that sentence are grounds, and grounds are what the marks are for.

Four questions to ask any source

1. What are the units, and is this a total or a rate? 2. What are the two most extreme numbers here, and what is the gap between them? 3. What would I still need to know? 4. Who gains, who pays, and over what period? Four questions, thirty seconds, and they cover most of the 32 AO3 marks on Paper 2.

Checkpoint — the AO3 toolkit

Four questions on working from a source.

Score: 0 / 4

Question 1

Using Table 1, which statement is the strongest AO3 point?

A The dam costs more than the wind farm

B The dam floods a lot of land

C The dam costs $420 m against $300 m, but over its working life that is $7.0 m per year against $12.0 m per year, so the dam is the cheaper of the two

D Wind farms are better for the environment

C quotes both ends, does something with the numbers, and reaches a conclusion the raw table appeared to contradict. A and B are true but could have been written without the figures. D is an opinion that the table does not support — the table says nothing at all about emissions.

Question 2

Which of these is a valid "what the source does not show" point for Table 1?

A It does not show the capital cost of the wind farm

B It does not show what fills the supply gap when the wind farm is not generating

C It does not show how many people are moved by the dam

D It does not show the working life of the dam

B is a genuine gap and an important one, because the answer to it changes the real cost of scheme B. A, C and D are all rows that are in the table — $300 m, 1200 people and 60 years — and naming something the source does show is the commonest way to throw this mark away.

Question 3

A question says "Suggest which scheme should be built. Justify your answer using Table 1. [3]". Which is true?

A Only one of the two schemes can gain full marks

B Either scheme can gain full marks; the marks are for the reasoning, not the choice

C You should choose both and explain why

D You should say it is impossible to decide

Suggest means there is no single right answer, and the mark scheme will say so. What it will not credit is a choice with no figures behind it, or a refusal to choose. Pick one, support it with two numbers from the table, and then name what the table cannot tell you and how that affects the decision — that third sentence is usually the third mark.

Question 4

Why is "the capital cost" row not enough on its own to say which scheme is better value?

A Because the numbers are in millions

B Because it is the cost of building only, and the schemes last for different lengths of time

C Because costs always rise

D Because the wind farm is smaller

Reading the heading is move 1 for a reason. Capital cost is the cost of building, so it excludes running, maintenance and decommissioning, and the two schemes run for 60 and 25 years, so the same capital buys very different amounts of service. Whenever a table gives you a lifetime, it is inviting you to divide by it.

5 · The eight Topic 1 traps▶

Eight places where Topic 1 answers lose marks that the student had the knowledge to earn. Each of these has appeared in the mark schemes of this topic’s papers, and each is a single sentence to fix.

Trap 1 — Nuclear power is not renewable

Nuclear generation releases almost no carbon dioxide, so it feels as though it belongs with wind and solar. The syllabus at 1.4.2(b) puts nuclear power using uranium firmly with the fossil fuels under non-renewable, because uranium is a mined ore and is not replaced.

The fix: Low carbon describes the emissions. Renewable describes the supply. A resource can be one without being the other, and this classification is about the fuel.

Trap 2 — A heat pump transfers heat — it does not make it

The syllabus wording at 1.5.2(c) and (d) is transfer of heat from the ground and from the air. A heat pump is not a generator and not an energy resource; it moves heat that already exists into the building, which is why it delivers more heat than the electricity it consumes.

The fix: If a heat pump made energy it would be in 1.4 with the energy resources. It is in 1.5, under conservation and management, because it is an efficiency measure. And it runs on electricity, so how clean it is depends on the grid.

Trap 3 — "Profitably" is not in the 0680 definition of an ore

An ore is rock containing minerals and metals. That is the whole of 1.2.1. The version you may have read elsewhere — rock from which a metal can be extracted profitably — is not this syllabus.

The fix: The profit idea is real, but it lives one objective away at 1.2.3(h), where cost and profit are a factor in the decision to extract. Definition: what the rock contains. Decision: whether it is worth digging up.

Trap 4 — Permeability is not porosity

Permeability is the ability of water to pass through the pore spaces of rock and soil. It is about water moving through. How much water a rock can hold is a different property, and the two do not have to go together.

The fix: Shale is the proof. It has pore spaces, but they are barely connected, so water and gas cannot move through it — and that is exactly why the rock has to be fractured before shale gas will flow. If you can explain shale, you have understood permeability.

Trap 5 — Legislation and enforcement are two marks, not one

They are listed separately at 1.3.3(e) and 1.3.3(f). Legislation is writing the rule — limits, licences, standards. Enforcement is inspection, monitoring, fines and withdrawing a licence when the rule is broken.

The fix: Two entries in a syllabus list means two marks are on offer. It is also the most reusable limitation you own: almost every management strategy in Topic 1 depends on being enforced, and enforcement costs money and needs inspectors.

Trap 6 — Restoration is not repurposing

1.2.5(a) restoration is putting the land back: replacement of overburden, soil improvement, bioremediation, tree planting. 1.2.5(b) repurposing is giving the site a new job: landfill, a lake, recreation, a nature reserve.

The fix: Answering a restoration question with "turn it into a lake" is a real answer to a different question, and it can lose every mark in the part at once. Read which of the two words is in the question.

Trap 7 — Phytomining uses plants; bioleaching uses bacteria

Both are biological extraction at 1.2.2(c), and they are listed as two methods. Phytomining: plants take up metal ions, are harvested, are burnt, and the metal is extracted from the ash. Bioleaching: bacteria produce a solution — a leachate — containing a compound of the metal.

The fix: Three stages in phytomining means three marks are available. The word phyto means plant; if your answer mentions bacteria, you have answered the other half of the objective.

Trap 8 — Coal comes from plants; oil and gas come from marine organisms — and every generation chain ends the same way

At 1.4.1, coal forms from buried plant material, while petroleum and natural gas form from the remains of tiny marine organisms. Both then need heat and pressure over millions of years.

The fix: And in 1.4.3, whatever the resource, the last two links are always the same: something turns a turbine, the turbine drives a generator, the generator produces the electricity. Leaving the generator out is the commonest way to lose the last mark of a three-mark generation question.

Checkpoint — the eight traps

One question on each.

Score: 0 / 8

Question 1

Why is nuclear power using uranium classified as non-renewable?

A Because it releases carbon dioxide

B Because uranium is a mined ore that is used up far faster than it is replaced

C Because nuclear power stations are expensive

D Because it produces radioactive waste

The classification at 1.4.2 is about whether the fuel is replaced, and uranium is not. Nuclear generation releases almost no carbon dioxide, so A is simply untrue. C and D are real objections to nuclear power and would be worth marks in a discuss question — but neither is the reason for the classification.

Question 2

Which sentence about an air source heat pump would score?

A It makes heat out of the air

B It generates energy from the outside air

C It transfers heat from the outside air into the building, so it delivers more heat than the electricity it uses

D It converts air into heat

The syllabus word is transfer. A, B and D all describe a device that creates energy, and describing a heat pump that way loses the mark even though the rest of the answer may be right. There is usable heat in air well below freezing, and the pump moves it indoors.

Question 3

Which is the 0680 definition of an ore?

A Rock from which a metal can be extracted profitably

B Rock containing minerals and metals

C A mineral that contains a metal

D Rock that has been mined

B is the syllabus wording at 1.2.1 and it is short enough that there is no excuse for losing the mark. A is the definition used in a lot of other courses, which is exactly why it is the tempting answer; the profitability idea belongs at 1.2.3.

Question 4

A rock has many pore spaces but the spaces are not connected to each other. What can you say about it?

A It is permeable, because it has pore spaces

B It is impermeable, because water cannot pass through it

C It must be an igneous rock

D It cannot contain any water

Permeability is about water passing through, which needs the pores to be connected. This is shale exactly: it holds gas formed inside it, but nothing can flow out, which is why fracking exists. C is wrong — shale is sedimentary. D is wrong — unconnected pores can still hold water.

Question 5

A 2-mark question asks how a government can manage mineral resources sustainably. A student writes "the government passes laws about mining". What is missing?

A Nothing; that is worth both marks

B Enforcement — checking the rules are followed and penalising those who do not

C The name of a country

D A definition of sustainability

Legislation and enforcement are 1.3.3(e) and 1.3.3(f), two separate entries, so two marks are on offer and the student has taken one. A law with no inspection behind it changes nothing, which is why Cambridge lists them apart.

Question 6

A question asks for strategies to restore land damaged by extraction. Which answer scores nothing?

A Replacing the overburden that was stripped off at the start

B Adding organic matter and nutrients to improve the soil

C Flooding the pit to make a lake for recreation

D Planting trees to bind the surface and rebuild a habitat

C is repurposing, 1.2.5(b), not restoration, 1.2.5(a). It is a perfectly good answer to a question that was not asked. Read which of the two words appears in the question — it is the difference between full marks and none.

Question 7

Which describes bioleaching rather than phytomining?

A Plants are grown on low grade ore and take up metal ions

B The harvested plants are burnt and the metal is extracted from the ash

C Bacteria are used to produce a solution containing a compound of the metal

D The plants concentrate the metal in their tissues as they grow

Bioleaching uses bacteria; phytomining uses plants, in three stages — grow, harvest and burn, extract from the ash. Both are biological extraction at 1.2.2(c), and both can be asked for by name.

Question 8

A 3-mark question asks how wind power is used to generate electricity. A student writes: "The wind blows the blades round and this makes electricity." What is missing?

A The direction of the wind

B That the turning turbine drives a generator, which is what produces the electricity

C The height of the tower

D The name of a country that uses wind power

The turbine turns; the generator produces the electricity. They are two different pieces of equipment and the mark scheme pays for both. The chain is the same for every resource in 1.4.3, so learning it once covers all of them: something turns a turbine, the turbine drives a generator, the generator produces electricity.

6 · Two source-led practice sets▶

Two complete source-led sets, of the kind Paper 2 is made of. Work each one on paper before you open the model answers — reading a model you have not attempted teaches almost nothing.

Practice set 1 · 12 marks · AO3

Figure 1 — the energy cost of a tonne of metal, from ore and from scrap

For each of four metals, the chart gives the energy needed to produce one tonne of the finished metal from its ore, and the energy needed to produce the same tonne from recycled scrap. Both bars are in gigajoules per tonne.

Figure 1. Constructed for practice and not measurements from named plants, but the size of the gap — enormous for aluminium, much smaller for steel — is typical of the real difference between smelting an ore and remelting scrap.

(a)(i)[1]

Using Figure 1, identify the metal for which recycling saves the largest amount of energy per tonne, and state that saving.

(a)(ii)[2]

Calculate the percentage of the energy that is saved by producing aluminium from scrap rather than from ore. Give your answer to 3 significant figures and show your working.

(b)[3]

Describe the pattern shown in Figure 1. Use figures from the chart in your answer.

(c)[2]

State two things Figure 1 does not tell you.

(d)[4]

A government adviser says: "Recycling effort should be concentrated on aluminium." Using Figure 1, discuss this view and reach a supported judgement.

Model answers — practice set 1Open only after you have written all five parts.

Each part is marked the way the real mark scheme is: figures for the describe, a method mark for the calculation, and a judgement worth its own mark at the end.

(a)(i) — 1 mark

Aluminium, a saving of 161 GJ per tonne (170 − 9). Both the metal and the figure with its unit are needed.

(a)(ii) — 2 marks

M1 for the correct fraction: (170 − 9) ÷ 170 × 100, or 161 ÷ 170 × 100. A1 for 94.7%. Dividing by the scrap figure instead of the ore figure gives 1790%, which should look wrong immediately — a saving cannot be more than 100% of what you started with.

(b) — 3 marks, 1 per point, capped at 1 if no figures are used

For every metal shown, producing it from scrap needs less energy than producing it from ore. The gap is by far the largest for aluminium, 170 against 9 GJ, which is about 19 times as much energy from ore. The gap is smallest for steel, 22 against 8 GJ, a saving of only 63.6% against aluminium’s 94.7%. Accept also: the scrap bars are all close together, 4 to 9 GJ, while the ore bars range from 14 to 170 GJ — so almost all of the variation between metals comes from the extraction, not from the remelting.

It gives energy only, so nothing about the cost, the water used, or the pollution released. It gives no quantities — how much of each metal a country uses, so the total energy at stake cannot be worked out. It says nothing about the energy needed to collect, sort and transport the scrap, which is part of the real cost of recycling. It does not say how much scrap is actually available, and you cannot recycle metal that has not been thrown away yet. It gives no information about quality — whether recycled metal is as good as new metal for every use.

(d) — 4 marks: up to 3 for both sides, 1 for a supported judgement

In favour, with figures: aluminium saves 161 GJ per tonne, which is 94.7% of the energy and more than the other three savings put together (32 + 14 + 10 = 56 GJ). Per tonne recycled, no other metal comes close. Against, with figures: the chart is per tonne, and the world uses far more steel than aluminium, so 14 GJ saved on each of a very large number of tonnes of steel could still outweigh 161 GJ on a small number of tonnes of aluminium — and the chart cannot settle that, because it gives no quantities. Concentrating on one metal also means the collection systems for the others are not built, and copper still saves 80.0%. Judgement: on energy saved per tonne the adviser is clearly right, but the decision turns on how much of each metal is actually thrown away, which is the one thing Figure 1 does not show. So aluminium should be the priority per tonne collected, not the only target.

Aluminium saves 161 GJ per tonne, 94.7%, but the chart is per tonne and gives no quantities — that gap is where the judgement mark is.

Practice set 2 · 10 marks · AO2 and AO3

Table 2 — five ways for a household to use less energy

A household is considering five measures. Electricity costs $0.20 per kWh. Payback time is the number of years of savings needed to cover the installation cost. One figure has been left out deliberately.

Measure	Installation cost / $	Electricity saved / kWh per year	Payback time / years
LED lighting throughout	120	400	1.5
Loft insulation	600	1500	2.0
Air source heat pump	9000	4200	not given
Solar panels with a battery	12000	3000	20.0
Double glazing	4500	900	25.0

Table 2. Constructed for practice. The savings are annual and assume the household keeps using the same amount of heating and lighting as before.

(a)[1]

Using Table 2, identify the measure with the shortest payback time, and state that time.

(b)[2]

Calculate the payback time for the air source heat pump. Give your answer to 3 significant figures and show your working.

(c)[3]

Explain why the measure that saves the most electricity each year is not the measure a typical household is most likely to install.

(d)[4]

A government has enough money to pay for one of these measures in every home in a town. Using Table 2, discuss which it should choose, and reach a supported judgement.

Model answers — practice set 2Open only after you have written all four parts.

Part (b) is the calculation the table left out on purpose. Part (d) is the five-move frame from section 2, applied to a table instead of to a topic.

(a) — 1 mark

LED lighting throughout, 1.5 years. The measure and the figure are both needed.

(b) — 2 marks

Annual saving in money: 4200 × $0.20 = $840 per year. M1 for $9000 ÷ $840, A1 for 10.7 years. The commonest error is dividing the cost by the kWh and reporting 2.14, which is dollars per kWh saved, not a time. Check the unit of your answer against the unit the question asked for.

The largest annual saving is the Air source heat pump at 4200 kWh per year (1). But it also has one of the highest installation costs, $9000, and the household has to find that money before it sees any saving at all (1). Its payback time is about 10.7 years, so the household only gains if it is still in the house a decade later — which is why the cheap, quick measures like led lighting throughout at 1.5 years and loft insulation at 2.0 years are the ones that actually get fitted (1).

(d) — 4 marks: up to 3 for both sides using the table, 1 for a supported judgement

The case for loft insulation: $600 per home is the second cheapest in the table, so the money reaches the most homes, and at 1500 kWh saved per year it delivers 3.8 times the annual saving of led lighting throughout for five times the cost. Its payback of 2.0 years is short enough that the households would probably not have needed help for long. The case for the heat pump: it saves 4200 kWh a year, nearly three times as much as insulation, and at $9000 it is the measure households are least able to afford alone — so it is where public money changes what actually happens rather than paying for something that would have been done anyway. Against each: the same $9000 buys a heat pump for one household or insulation for 15 households, and the table gives no lifetimes, no maintenance costs and nothing about how the electricity is generated, so it cannot tell you which choice saves more carbon dioxide. Judgement: if the aim is the largest total energy saving for the money, insulation wins on the figures in the table. If the aim is to reach the households that could never do it themselves, the heat pump wins. So the decision turns on which of those two aims the government has — and the table, which gives no incomes and no lifetimes, cannot settle it.

Shortest payback 1.5 years; heat pump 10.7 years. The judgement turns on what the money is for, which the table does not say.

Checkpoint — the practice sets

Three questions on what the two sources will and will not support.

Score: 0 / 3

Question 1

In Figure 1, why is "recycling saves energy for every metal shown" worth only one mark on a [3] describe question?

A Because it is not true

B Because it quotes no figures, and a describe question on a source is marked for figures

C Because it is too short

D Because it does not name a metal

It is true, and it is the right kind of statement — it just could have been written without looking at the chart. Attach numbers: 170 against 9 GJ for aluminium, 22 against 8 for steel. Two pairs of figures turn one mark into three.

Question 2

In Table 2, why does the measure with the largest annual saving have one of the longest payback times?

A Because it saves less money than it appears to

B Because payback compares the saving with the installation cost, and that cost is $9000

C Because electricity prices are falling

D Because it does not work in winter

Payback is cost divided by annual saving, so a big saving bought with a very big cost still takes a long time. At $9000 and 4200 kWh a year, the heat pump takes 10.7 years. This is the arithmetic behind one of the most important limitations in 1.5.3: the measures that save the most are the ones the households who need them most cannot afford.

Question 3

Which of these is a valid "what the source does not show" point about Table 2?

A It does not give the cost of double glazing

B It does not say how long each measure lasts, so the total lifetime saving cannot be worked out

C It does not give the payback time for LED lighting

D It does not give the price of electricity

B is a real gap and it matters: a measure with a 25-year payback is a very different proposition depending on whether it lasts 15 years or 40. A, C and D are all in the table or the caption — $4500, 1.5 years and $0.20 per kWh — and naming something the source does show is the standard way to lose this mark.