A-Level Geography Past Papers & Drilling (Paper 4): Climate and Disease Themes

Question 1

(a) Total emissions = 6.2 x 7,500,000 = 46,500,000 tonnes = 46.5 Mt; after a 40% cut the target is 46.5 x 0.6 = 27.9 Mt, a reduction of 18.6 Mt. (3 marks)

(b) Over 30 years the rise is 3.7 x 30 = 111.0 mm (11.1 cm) and over 80 years 3.7 x 80 = 296 mm = 29.6 cm. This is a linear estimate: in reality the rise accelerates through ice-sheet feedbacks. (4 marks)

(c) A mitigation tool such as carbon pricing or replacing coal with renewables acts on the source of emissions and lowers the concentration of greenhouse gases, whereas an adaptation measure such as higher sea walls or relocating low-lying infrastructure addresses impacts that are already happening and cuts the losses they cause. (3 marks)

Question 2

Line of argument: mitigation sets the long-term ceiling on risk while adaptation deals with losses now; the two are not substitutes, and the priorities differ between developed and developing regions.

(1) Mitigation: with emissions of 46.5 Mt and a 40% cut target of 27.9 Mt, mitigation requires structural change – coal still supplies 42% of electricity; carbon pricing, emissions trading and renewable subsidies can cut emissions, but success depends on international coordination and the risk of carbon leakage.

(2) Adaptation: with sea level rising 11.1 cm in 30 years and 29.6 cm in 80, coastal cities need engineering (sea walls, drainage) alongside non-structural measures (planning, warning, insurance); the benefits are immediate but do not tackle the cause.

(3) Equity and capacity: low-emitting regions often face the greatest impacts, so adaptation depends on international finance and technology transfer, and cities with weak governance struggle with both.

(4) Evaluation: the most effective response pairs mitigation to cap long-term risk with adaptation to cut present losses, tracked against emissions, temperature and tide-gauge data; mitigation alone leaves vulnerable communities exposed first, while adaptation alone becomes more expensive as warming continues. (20 marks)

Question 3

(a) Attack rate = 180 / 2400 x 100 = 7.5%; incidence = 180 / 2400 x 1000 = 75 per thousand. (4 marks)

(b) Prevalence = 420 / 100,000 x 100 = 0.42%; the herd immunity threshold is (1 – 1 / 2.5) x 100 = 60.0%. (3 marks)

(c) Doublings = log(480 / 120) / log 2 = 2, so the doubling time is 14 / 2 = 7 days. Geography matters because population density and housing shape contact rates, mobility (commuting, air travel) extends the range of spread, and access to healthcare and vaccination coverage decide whether an outbreak can be contained. (3 marks)

Question 4

Line of argument: geographical factors set the speed and reach of spread, but policy intervention and vaccine coverage can rewrite the outcome, so geography is a risk factor rather than a destiny.

(1) Density: higher density raises contact rates – here an attack rate of 7.5% (75 per thousand) – and airborne disease spreads faster in crowded housing.

(2) Mobility: cases rising from 120 to 480 in 14 days (a 7-day doubling time) show how transport hubs and cross-border movement turn a local outbreak into several clusters, and air networks shrink the friction of distance.

(3) Access to healthcare: remote areas have lower testing and vaccination coverage, and with R0 at 2.5 an outbreak needs 60% herd immunity to stop, which under-resourced regions rarely reach, so waves recur.

(4) Evaluation: geography explains much of the variation, yet policy (lockdowns, testing, vaccine allocation) and socio-economic conditions (housing, occupational exposure) matter just as much; strengthening primary care and community surveillance offsets geographical disadvantage better than border controls alone. (20 marks)

Question 1

Trade balance = 512 – 468 = a surplus of 44 bn; trade is (512 + 468) / 3200 x 100 = about 30.6% of GDP; aid is 18 / 240 x 100 = 7.5% of government spending. An open economy is sensitive to external demand, and high aid dependence ties public investment to donor policy.

Question 2

Daily landfill input = 2600 x (1 – 32%) = 1768 tonnes a day; annual input = 1768 x 365 = 645,320 tonnes; capacity lasts 6,200,000 / 645,320 = about 9.6 years. Raising the recycling rate, separating food waste and producer-responsibility schemes all extend it by cutting waste per person.