Course review
Review each learning objective in this topic, then open its concept explanation or question set.
Learning objective
• Ensure chemical elements remain available to living organisms • Human impact affects ecosystem sustainability
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Stores: equilibrium with environment • Sinks: net accumulation • Sources: net release
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Organic: organisms, crude oil, natural gas • Inorganic: atmosphere, soils, oceans
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Photosynthesis, feeding, defecation, respiration, death, decomposition
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Capturing atmospheric CO₂ and storing as solid/liquid • Natural: trees absorb CO₂ → biomass • Fossilization into coal, oil, natural gas
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Sink: photosynthesis > respiration (e.g., young forest) • Store: balanced (e.g., mature forest) • Source: respiration > photosynthesis (e.g., forest fire)
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Fossil fuels are stores of carbon with unlimited residence times • They were formed when ecosystems acted as carbon sinks in past eras and become carbon sources when burned • Consider: the concept of fossil fuels but not the detail of how and when coal, oil and natural gas were formed
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Agricultural systems can act as carbon stores, sources and sinks, depending on the techniques used • Regenerative agricultural methods, such as crop rotation, cover crops and no till, will promote the role of soil as a carbon sink whereas drainage of wetland, monoculture • Cropping over a longer timescale (e.g., timber production) and the subsequent use of harvested products will also affect these roles
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Carbon dioxide is absorbed into the oceans by dissolving and is released as a gas when it comes out of a solution • While oceans act as a carbon sink, the human use of fossil fuels releases inorganic carbon at a faster rate than oceans can absorb it
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Increases in concentrations of dissolved carbon dioxide cause ocean acidification, harming marine animals • Small decreases in pH can interfere with calcium carbonate deposition in mollusc shells and coral skeletons
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Measures are required to alleviate the effects of human activities on the carbon cycle • Consider at least three required measures • These include low-carbon technologies, reduction in fossil-fuel burning/soil disruption/deforestation, carbon capture through reforestation and artificial sequestration
Start with the concept explanation, then practise to create mastery evidence.