Table 1 shows the recorded atmospheric composition and average internal temperature of a closed-system planetary simulator, 'Gaea-II', over four distinct experimental phases of biological succession.
| Experimental Phase | Dominant Biological System | Carbon Dioxide (CO2CO_2CO2) Concentration | Oxygen (O2O_2O2) Concentration | Average Simulator Temperature |
|---|---|---|---|---|
| Phase 0: Baseline | Sterile (No biological organisms) | Extremely high (85%) | 0% | 42∘C42^\circ\text{C}42∘C |
| Phase I: Microalgae | Engineered cyanobacteria inoculated | Intermediate (12%) | Trace amounts (1.5%) | 28∘C28^\circ\text{C}28∘C |
| Phase II: Canopy | Mature, high-density vertical forest farms | Low (approx. 0.04%) | High (approx. 20.5%) | 15∘C15^\circ\text{C}15∘C |
| Phase III: Harvesting | Clear-cutting / crop removal (reduced biomass) | Increasing (approx. 0.08%) | Stable (approx. 20.5%) | 18∘C18^\circ\text{C}18∘C |
Explain the mechanisms by which the introduction and subsequent harvesting of photosynthetic life modified the atmospheric composition and the internal temperature of the Gaea-II simulator.
In your answer, refer to the data in Table 1 and include:
97 exam-style questions on Edexcel GCSE Chemistry 9.2 Earth and atmospheric science, covering 9.2.1 The Earth's early atmosphere, 9.2.2 How the atmosphere evolved, 9.2.3 Chemical test for oxygen, and 9.2.4 The greenhouse effect and climate change. Each one has a worked solution and a mark scheme showing where the marks go.