The Four Spheres
Name the four spheres of the Earth.
Atmosphere, Lithosphere, Hydrosphere, Biosphere.
What does biodiversity mean?
The variety of all living things in an ecosystem.
What is an example of human-induced environmental change?
Urbanisation, deforestation, or pollution.
What is a natural environmental change?
A change caused by nature, not humans. E.g., floods or volcanoes.
How many body paragraphs for your extended response?
2 SEEL
Which sphere contains all living things?
The Biosphere.
Why is biodiversity important for ecosystems?
It helps ecosystems stay stable and resilient to change.
How does agriculture affect the environment?
It can cause soil degradation and water pollution from fertilisers; overgrazing/overfishing; land clearing; emissions.
How can flooding bring both positive and negative changes to an environment?
Floods can destroy homes and habitats, but they also deposit nutrients that make the soil more fertile and help plants grow.
What order should you complete the exam?
Longest to shortest / back to front (Extended Response - Short Answer - Multiple Choice).
How does deforestation show an interaction between spheres?
Removing trees (biosphere) changes soil structure (lithosphere) and affects rainfall (atmosphere).
Name one cause of biodiversity loss.
Habitat destruction, pollution, overfishing, or climate change.
How does urbanisation impact the environment?
It replaces natural habitats with buildings and roads, increases pollution, and changes water flow and temperature in local areas.
Explain how one natural change can impact all four spheres.
A bushfire affects the biosphere by killing plants and animals, the atmosphere by releasing smoke, the lithosphere by burning soil, and the hydrosphere when ash and debris enter waterways.
What should you do if a question asks you to use a source?
Explicitly reference the source - "In Source A..."; "Source B shows that..."
How does the hydrosphere influence the lithosphere during a flood?
Water erodes soil and reshapes landforms.
How does location impact biodiversity?
Latitude - temperate/rainfall; altitude - oxygen levels and temperature; access to water; human activities - land clearing/pollution/protected areas.
Explain how population growth contributes to environmental change.
More people need housing, food, and resources, leading to deforestation, pollution, and greater pressure on ecosystems.
What is an ecological footprint? Include the categories.
An ecological footprint measures the impact a person or community has on the environment by showing how much land and water is needed to support their resource use. Includes: carbon, forest, cropland, grazing land, fishing grounds, and built-up land.
What is an 'explain' question asking you to do?
Relate cause and effect. Provide why and/or how.
Explain how the hydrosphere, lithosphere, and atmosphere support the biosphere.
The hydrosphere provides water, the lithosphere supplies soil and nutrients, and the atmosphere provides air and climate. Together, they interact to create the conditions needed for life in the biosphere.
Explain how human activity can reduce biodiversity in both land and water environments.
Land clearing destroys habitats; runoff and pollution harm aquatic life.
Explain how human activity in one sphere can cause flow-on effects in others.
Example: Deforestation (lithosphere) increases carbon in the atmosphere, which changes rainfall (atmosphere) and harms ecosystems (biosphere).
Explain how the ecological footprint shows us how humans impact the biosphere.
Shows how the more resources we use, the more we reduce habitats, harm species, and disrupt ecosystems. Also shows the specific areas we are impacting e.g., oceans, carbon emissions.
What should you be doing between now and Monday?
Completing Revision Booklet & lots of practice questions. Give these to your teacher for feedback!