Reducing the use of resources

In a nutshell

The Earth has a finite (limited) supply of resources, which must be used sustainably. Sustainable means using resources in a way which minimises harm to the environment and leaves enough resources for future generations. Overuse of resources, lack of recycling and pollution are issues in sustainability.

Resources

Definition

Resources are useful materials. Humans compete with other animals for natural resources, such as:

Food
Water
Space

Recycling

Definition

Recycling is converting resources, that have already been used, into other useful materials. Recycling is a sustainable practice and there are many materials which can be recycled, including:

Metal
Paper
Glass

Mining vs. recycling metal

Metals can also be extracted by mining. The table below compares the process of extracting metals by mining and recycling metals.

Extracting metals by mining	Recycling metals
Exploits high-grade metal ores, which are non-renewable and already running out.	Conserves high-grade metal ores.
High energy requirements in the mining process.	Lower energy requirements during the recycling process.
Harmful to the environment.	Less harmful to the environment.

Recycling brass

Brass is an alloy metal made of copper and zinc. Brass can be used to make locks, zippers and electrical plug sockets. The process of recycling brass is described below.

PROCEDURE

1.	Brass is collected and separated from other metals.
2.	In the processing step, the brass is squashed by machines to form a flat layer of metal.
3.	Solid brass is heated to form molten brass.
4.	Molten brass is purified to remove contaminants.
5.	The pure molten brass is cooled down to form a solid.
6.	The brass is transported to factories.

This process is used to recycle other metals too.

Recycling glass

Many glass products, such as bottles, can be reused, which is sustainable as it minimises the cost and energy to recycle the glass. Glass products may be recycled if they cannot be reused. The glass is sorted by colour and chemical composition and then it is crushed by machines so that it is easier to melt. Once the glass is melted, it can be reshaped to make different products, such as jars

Advantages and disadvantages of recycling

There are many advantages and disadvantages of recycling. These are listed below.

Advantages	Disadvantages
Conserves resources that are limited.	Sorting and purifying materials is time-consuming, costly and requires energy.
More space is available as landfill sites are reduced.	Transporting materials requires energy.
Less fossil fuels are burned to produce resources which reduces the the emission of pollutants, such as greenhouse gases.	The energy requirements of recycling are usually met by burning fossil fuels which contributes to the emission of pollutants, such as greenhouse gases.