Earth's resources and sustainability

Humans use the Earth's resources for warmth, shelter, food and transport.

• Natural resources, such as wood, wool, cotton and rubber, come from farming or from nature.
• Synthetic materials are made by chemists to supplement or replace natural ones. For example, synthetic fibres such as nylon are used alongside wool, and fertilisers from the Haber process add to manure.

Chemistry plays a big part in improving farming and industrial processes so they can meet the needs of a growing population.

Finite resources will run out, because they are being used much faster than they form. Examples: crude oil, coal, natural gas and metal ores.

Renewable resources can be replaced as fast as we use them. Examples: wood from managed forests, plant-based materials, and energy from the wind and Sun.

Sustainable development meets the needs of people today without stopping future generations from meeting theirs. Chemists help by finding processes that use less energy, produce less waste and use renewable raw materials.

To judge how sustainable a process is, ask:

• Are its raw materials finite or renewable?
• How much energy does it need, and where does that energy come from?
• How much waste and pollution does it make?
• Can the product be reused or recycled at the end of its life?

The answers often pull in different directions. A process can use renewable raw materials but need a lot of energy, so weigh each point and come to a judgement.

Fermentation uses a renewable raw material and less energy for heating, so on those points it is more sustainable. But growing the crops uses land that could grow food, and the ethanol needs extra energy to purify.