SHS DirectorySHS MatchLesson PlansGES Promotion Past QuestionsStudent Lesson NotesBlogs

Basic 5 · Our World and Our People · The Environment and the Weather

Caring for the Environment and the Shape of the Earth

In this topic you will explain ways to care for the environment and describe the shape of the earth with evidence.

By the end of these notes you should be able to:

  • Explain ways to reduce greenhouse gases and care for the environment
  • Describe the shape of the earth
  • Give evidence that the earth is round

What you already know

  • Greenhouse gases and climate change

Copy everything that has a blue line on its left into your notebook. The other parts are for reading.

Strand
All Around Us
Sub-strand
The Environment and the Weather
Indicator
B5.2.1.2.1 – Explain ways to care for the environment and describe the shape of the earth

Introduction

The earth is our only home. To protect it, we must care for the environment. Scientists and explorers have also shown that this home is shaped like a ball.

1. Ways to Care for the Environment

Caring for the environment
ActionHow it helps
plant treestrees absorb carbon dioxide and give shade
stop bush burningreduces smoke and protects soil and animals
use gas or improved stovesburns less charcoal and firewood
use solar energyreduces fuel burning
walk or cycle short distancesreduces vehicle smoke
reduce, reuse and recycleless waste in dumps
dispose of waste properlyprevents pollution and methane from open dumps
switch off lights and appliancessaves energy

2. The Shape of the Earth

The earth is round, shaped like a ball. Its shape is called a sphere. It is very slightly flattened at the North and South Poles and bulges a little at the equator, so scientists call it an oblate spheroid. Because the earth is so big, it looks flat to us when we stand on it.

The earth photographed from space showing Africa
Figure 1: The earth is round Draw the earth as a sphere and mark the equator and the poles.Photo: NASA Goddard Space Flight Center from Greenbelt, MD, USA, Public domain, via Wikimedia Commons

3. Evidence That the Earth Is Round

Evidence
EvidenceExplanation
photographs from spaceastronauts and satellites show a round earth
ships at seaa ship sailing away disappears hull first, then the mast, because of the earth's curve
sailing round the worldFerdinand Magellan's expedition (1519–1522) sailed west and returned to its starting point
eclipse of the moonthe earth's shadow on the moon is always curved
the horizonfrom a high place, the horizon appears curved and you can see farther
sunrise timesthe sun rises at different times in different places

4. Caring for Our Round Home

Because the earth is a sphere, the air and seas are shared by all countries. Smoke from one country can affect another, and plastic thrown into the sea at Accra can wash up on beaches far away. Caring for the environment is therefore everyone's duty, and countries work together through agreements such as the Paris Agreement on climate change.

New words

sphere
A perfectly round, ball-shaped object.
oblate spheroid
A sphere slightly flattened at the poles.
horizon
The line where the sky seems to meet the earth or sea.
eclipse
When one object in space blocks the light to another.
satellite
An object that moves around the earth in space.
recycle
To make used materials into new products.

Summary

  • Planting trees, stopping bush burning and saving energy protect the environment.
  • The earth is a sphere, slightly flattened at the poles.
  • Photos from space, ships and eclipses prove the earth is round.
  • Caring for the earth is the duty of all people and nations.

Class activity: Ship Over the Horizon

  1. Place a paper ship on a ball (globe).
  2. Move it around the curve while a friend watches at eye level.
  3. Record which part disappears first.

You need: Locally made clay globe, Ghana map, Printed photographs of clean, Polluted Ghanaian surroundings

Exercises

Answer in your exercise book first, then check your answers.

  1. 1. What is the shape of the earth?

    • A. Sphere
    • B. Flat square
    • C. Triangle
    • D. Cube
    Show answer
    Answer: SphereIt is round like a ball.

  2. 2. When a ship sails away, which part disappears first?

    • A. The hull (bottom)
    • B. The mast
    • C. The flag
    • D. Everything at once
    Show answer
    Answer: The hull (bottom)Because of the earth's curve.

  3. 3. Which action reduces greenhouse gases?

    • A. Planting trees
    • B. Bush burning
    • C. Burning tyres
    • D. Cutting forests
    Show answer
    Answer: Planting treesTrees absorb CO₂.

  4. 4. Photographs from space show the earth is round.

    • A. True
    • B. False
    Show answer
    Answer: TrueTaken by astronauts and satellites.

  5. 5. The earth's shadow on the moon is straight.

    • A. True
    • B. False
    Show answer
    Answer: FalseIt is always curved.

  6. 6. A sphere slightly flattened at the poles is an oblate ______.

    Show answer
    Answer: spheroidThe earth's true shape.

  7. 7. Give three pieces of evidence that the earth is round.

    Show answer
    Answer: Photographs from space, ships disappearing hull first, Magellan's voyage (or lunar eclipse).Any three.

  8. 8. Why is caring for the environment a duty for all countries?

    Show answer
    Answer: The earth is one sphere with shared air and seas, so pollution in one place affects others.Shared home.

Homework

  1. Make a model of the earth using clay or paper and mark Ghana on it.