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This final lesson brings together everything you have learned across Topics 7, 8 and 9 of the Edexcel B specification — the biosphere, forests under threat, and consuming energy resources. It provides key revision summaries, comparison tables, a glossary of essential terms, and detailed guidance on how to approach the Paper 3 decision-making examination. Use this lesson to consolidate your knowledge and sharpen your exam technique.
| Term | Definition |
|---|---|
| Biome | A large-scale ecosystem defined by its climate, vegetation and wildlife |
| Biosphere | The thin layer of the Earth where life exists |
| Ecosystem services | Benefits that humans receive from natural ecosystems (climate regulation, water purification, etc.) |
| Biodiversity | The variety of living organisms in an area |
| Nutrient cycling | The movement of nutrients between soil, living organisms and the atmosphere |
| Gersmehl diagram | A model showing nutrient stores (biomass, litter, soil) and transfers between them |
| Latosol | Deep, infertile, red soil found in tropical rainforests |
| Podzol | Thin, acidic, layered soil found in the taiga |
| Deforestation | The permanent removal of forest, usually to convert land to another use |
| Sustainable management | Using resources to meet present needs without compromising future generations |
| REDD+ | UN programme that pays countries to reduce deforestation |
| FSC certification | International certification for sustainably managed forests |
| Permafrost | Ground that remains frozen for at least two consecutive years |
| Energy security | Having reliable, affordable access to sufficient energy |
| Non-renewable | A resource that cannot be replaced once used (e.g. fossil fuels) |
| Renewable | A resource that is naturally replenished (e.g. solar, wind) |
| Intermittency | The variability of renewable energy sources that depend on weather |
| Fracking | Hydraulic fracturing to extract oil or gas from shale rock |
| Net zero | Balancing greenhouse gas emissions with removals from the atmosphere |
| Carbon sink | A system that absorbs more CO₂ than it releases (e.g. forests, oceans) |
| Positive feedback loop | A process where the output reinforces and amplifies the original change |
| Feature | Tropical Rainforest | Taiga (Boreal Forest) |
|---|---|---|
| Location | 0°–10° N/S of equator | 50°–70° N latitude |
| Climate | Hot (26–28°C year-round); wet (2,000–3,000+ mm/year) | Cold winters (−20 to −40°C); cool summers (10–20°C); low precipitation (300–600 mm) |
| Growing season | Year-round | 3–5 months |
| Dominant vegetation | Broadleaf evergreen trees; multi-layered structure | Coniferous trees (spruce, pine, fir, larch) |
| Soil type | Latosol — deep, red, infertile | Podzol — thin, acidic, layered |
| Nutrient cycling | Very fast — biomass is the largest store | Very slow — litter is a large store |
| Biodiversity | Extremely high (e.g. Amazon: 16,000 tree species) | Relatively low (fewer species, less complex food webs) |
| Carbon storage | ~250 billion tonnes (mainly in biomass) | ~1,770 billion tonnes (mainly in soils and permafrost) |
| Key adaptations | Buttress roots, drip tips, lianas, epiphytes | Needle leaves, conical shape, evergreen habit, shallow roots |
| Main threats | Agriculture (cattle, soy, palm oil), logging, mining, roads | Logging, oil/gas, mining, HEP, climate change (permafrost thaw, wildfires) |
| Key management | REDD+, ecotourism, indigenous rights, Soy Moratorium | Protected areas, FSC certification, sustainable forestry, indigenous rights |
| Feature | Non-Renewable (Fossil Fuels) | Nuclear | Renewable |
|---|---|---|---|
| Examples | Coal, oil, natural gas | Uranium | Solar, wind, HEP, geothermal, tidal, biomass |
| Availability | Finite — will eventually run out | Finite (uranium), but large reserves | Infinite — replenished naturally |
| CO₂ emissions | High (coal worst, gas least) | Very low during operation | Zero or very low during operation |
| Reliability | Very reliable — can generate on demand | Very reliable — 24/7 baseload | Variable — solar/wind are intermittent; HEP/geothermal are reliable |
| Cost | Relatively cheap (but volatile prices) | Very high construction costs; low running costs | Falling rapidly — solar is now cheapest new electricity in most countries |
| Environmental risk | Climate change, air pollution, oil spills | Radioactive waste; accident risk | Land use, visual impact, habitat disruption, mining for critical minerals |
| Energy security | Depends on imports for many countries | Uranium must be imported but small amounts needed | Domestic production possible almost everywhere |
You need named case studies with specific facts and statistics. Here is a quick-reference table:
| Case Study | Topic | Key Facts to Remember |
|---|---|---|
| Amazon (Brazil) | Rainforest deforestation | 80% caused by cattle; 215 million cattle; PPCDAm reduced deforestation 80% (2004–12); 17% of Amazon now deforested; tipping point at 20–25% |
| Indonesia (Borneo/Sumatra) | Palm oil deforestation | 85% of global palm oil; orangutan habitat loss (80%+; fewer than 100,000 remain); deforestation moratorium since 2011 |
| Costa Rica | Reforestation | Lost 50% forest cover by 1980s; payments for ecosystem services; 60%+ forest cover restored by 2021 |
| Canada's boreal forest | Taiga logging | ~1 million hectares logged/year; 90%+ by clear-cutting; woodland caribou declined 40%+ |
| Athabasca Oil Sands (Canada) | Oil extraction in taiga | 170 billion barrels of oil; 900 km² of forest destroyed; 220+ km² of toxic tailings ponds; only 1 km² reclaimed |
| Siberia (Russia) | Oil/gas and climate | 250,000+ km of pipelines; ~20,000 spills/year; 2021 wildfire season burned 18 million hectares |
| Sami people (Scandinavia) | Indigenous rights in taiga | ~80,000–100,000 people; reindeer herding threatened by mining, wind farms, climate change |
| European energy crisis (2022) | Energy security | EU imported 40% of gas from Russia; prices rose 400%+; accelerated renewables investment |
Paper 3 is unique among the Edexcel B GCSE Geography papers. It is a decision-making paper that uses pre-released resources (a resource booklet given to you several weeks before the exam). You will be assessed on your ability to use these resources, combined with your own knowledge, to analyse issues and make reasoned decisions.
| Feature | Detail |
|---|---|
| Duration | 1 hour 30 minutes |
| Total marks | 64 marks |
| Weighting | 25% of the total GCSE |
| Topics covered | Topic 7 (People and the Biosphere), Topic 8 (Forests Under Threat), Topic 9 (Consuming Energy Resources) |
| Pre-released resources | A resource booklet provided in advance; contains maps, data, photographs, graphs and text about a specific issue |
| Question types | Short answer, data response, extended writing, and a decision-making question |
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