Global Systems Year 9 Science Summary

  • Global Systems

    • Humans are significantly impacting Earth's natural systems in the Anthropocene era.
    • Technological advances enhance understanding but increase resource demand, leading to environmental costs.
    • Need for change is critical for future generations' sustainability.

  • Essential Questions

    • How do biospheres support life?
    • Importance of Earth cycles?
    • Human impacts on systems?
    • Climate influences?
    • Climate change effects on sea levels and biodiversity?

  • 'Big Five' Mass Extinctions

    • Defined by loss of at least 75% of species within 2 million years.
    • Notable extinctions:
    • End Ordovician: 86% species lost.
    • End Permian: 96% species lost.
    • End Cretaceous: 76% species lost.
    • Current extinction driven by human actions, risking sixth mass extinction.

  • The Biosphere

    • Earth’s life-support system consists of:
    • Atmosphere: the air, containing vital gases.
    • Lithosphere/Geosphere: solid rock and sediments.
    • Hydrosphere: all water forms.
    • Biota: all living organisms.

  • Earth's Cycles

    • Focus on the Carbon Cycle:
    • Carbon found in various forms (gas, liquid, solid).
    • Key processes: Photosynthesis (carbon absorption) and Cellular respiration (carbon release).

  • Human Impacts

    • Deforestation, mining, population increase, and pollution harm ecosystems and cycles.
    • Cultural burning practices help manage landscapes and reduce emissions.

  • Climate Patterns and Change

    • Factors affecting climate include the Earth’s tilt, land-water absorption, and geographical features.
    • The greenhouse effect traps heat, but increased fossil fuel use leads to global warming.

  • Biodiversity

    • Global warming impacts plant and animal biodiversity.
    • Potential extinctions can disrupt food webs and ecosystem stability.

  • Solutions to Stop Global Warming

    • Reduce fossil fuel use, enhance energy efficiency, shift consumption habits, and increase recycling.
    • Incorporate renewable energy sources (solar, wind).
    • Engage in sustainable practices to preserve ecosystems and biodiversity.