3.6 Sustainability

Natural sciences

Grade 8

Biodiversity

Module 29

Sustainability

The previous learning units focused on the survival strategies of organisms living on planet EARTH .

We know that the organisms and their habitats together make up the earth’s variety (biodiversity) and that nature is maintained in perfect balance because of this BIODIVERSITY .

There are 250 000 higher species of plants, 19 000 species of fish and 10 000 species of reptiles. Many more species of insects have been recorded. This wealth of life forms ensures that:

• there is an atmosphere that has the right combination and balance for our survival;
• the soil remains fertile for new plants to grow so that we and other animals will always have food;
• water is re-circulated.

South Africa is the only country in the world that has a complete plant kingdom within its borders, namely the fynbos biome of the Western Cape.

We in South Africa are fortunate to have a particularly rich variety of plants and animals in our own country. Are we aware of this wealth?

BIODIVERSITY SUPPORTS SUSTAINABILITY!

People are at the helm, but often fail to do the right thing

Activity: to take a stand on the maintenance of biodiversity in nature

Discuss the following question during the lesson:

• Are people part of a natural ecosystem, or are they unwanted guests who interfere and disrupt the balance?

Report the outcomes of the discussion in your own words (the dominant opinion within the group).

[ LO 3.2]

People are often accused of tapping nature’s resources for their own selfish needs.

If today were a typical day on planet Earth, 336 km² of tropical forest will have been destroyed by the end of the day to provide wood and by making way for roads, farms and plantations. A total of 112 km² will have changed into desert because of overgrazing or poor farming practices.

One and a half million metric tons of dangerous waste will have been dumped in the environment. Various estimates suggest that 50 to 100 plant and animal species will shortly become extinct.

By the end of the day, the world will be a little warmer, the rain will be a little more acidic and the earth’s web of life will be slightly more torn and tattered. (Chiras, 1993)

Scientists warn us against humankind’s destructive trends. the idea of sustainability suggests that it is possible for nature and human beings to exist in a win-win relationship. at the recent world conference in johannesburg, it became clear that many people believe that we can ensure a positive future for the whole world with the right management systems and the right inclination.

Activity: to reflect on the sustainability of the earth’s resources

1. List all the mistakes that people are making, with regard to the environment.

2. What do you understand as the meaning of SUSTAINABILITY?

3. Name THREE natural resources that are over-utilised.

4. Give the meaning of Mahatma Gandhi’s words (quoted below) in you own words:

"The world contains enough for everyone's need, but not for everyone's greed."

5. Why should we give serious reconsideration to our use of the environment?

Important terms are:

• HABITAT : specific place where an organism lives
• BIODIVERSITY : the variety of life on earth
• RESOURCES : everything that we use for our survival

Activity: to make a prediction about the earth’s future

The earth is like a spacecraft – all the provisions have been supplied and the journey has to be continued self-supportively!

Create an A4 poster to represent your view of the earth as a spacecraft.

Assessment of SUSTAINABILITY:

Could you answer the questions and provide a good representation of the earth for your poster?

[ LO 3.2]

Assessment

Learning outcomes 3: Science, society and the environment

The learner will be able to demonstrate an understanding of the interrelationships between science and technology, society and the environment.

This is evident when the learner

• understands sustainable use of the earth’s resources.

Memorandum

Activity: READING SKILL:

• Instruct the class to do silent reading.

Class activity: POSTER – SPACECRAFT EARTH

• The earth is like a spacecraft – all its supplies have been provided and it has to set out on its voyage – completely self-supportively!!
• Create an A4 poster to depict your image of the earth as viewed as a spacecraft in the present time.