Notes

The resources on the Earth are limited. It is important that the things we do now do not make things difficult or impossible for future generations. To achieve sustainable development, we need to balance these things carefully:

the need for economic development, where standards of living improve
respect for the environment and the resources it provides for us
Recycling is an important way to help us achieve sustainable development. We can recycle many resources, including:

glass
metal
paper
Glass
Glass is easily recycled. It can be melted and remoulded to make new objects, such as bottles. The energy needed to do this is less than the energy needed to make new glass from its raw materials. However, we need to sort different coloured glass ready for recycling, and transport it to the recycling plant.

Metal
Just like glass, it takes less energy to melt and remould metals than it does to extract new metals from their ores. Aluminium is a valuable metal that melts at a relatively low temperature, and is particularly attractive for recycling. However, a lot of metals that we use are mixtures called alloys, and it can be difficult to sort different metals ready for recycling.

Paper
Paper is not melted when it is recycled. Instead, it is broken up into small pieces and reformed to make new sheets of paper. This takes less energy to do than making paper from trees. However, paper can only be recycled a few times before its fibres become too short to be useful, and the recycled paper is often only good enough for toilet paper or cardboard. But it can be used as a fuel or compost instead.