Renewable resources are resources that can be replenished if they run out.
One example of a renewable resource is timber. Timber is a type of wood used for manufacturing furniture, constructing buildings, and making frames. Only a limited supply of Timber is available naturally, but it can be grown again once depleted. Trees and forests can be replanted once they run out, although it may take several decades for them to grow back.
Some natural products that are limited can be replaced by synthetic alternatives. For example, until the early 1900s, fertilisers were obtained from natural sources such as manure. However, artificial fertilisers were developed, which provide much more nutrients to plants.
The Haber process takes nitrogen from the air and reacts it with hydrogen to produce ammonia, which is the base of synthetic nitrogen fertilisers. The easy availability of fertilisers has increased crop yields and the quality of those crops. This higher crop yield is capable of supporting a growing population.
Another example of a natural resource that has been widely replaced by its synthetic alternative is rubber. People used to extract rubber from the sap of trees. However, scientists have synthesised polymers that are a substitute for natural rubber. Currently, around two thirds of the rubber used in the world is synthetic.
Non-renewable resources are resources that cannot be replenished once they run out.
One of the most important non-renewable resources is crude oil, which is extracted from the Earth’s crust. The oil is then processed by a method called fractional distillation. This process extracts a number of useful products from the oil, then condenses and purifies them for various uses.
Metal ores found in the Earth’s crust are another example of finite resources. There is a limited amount of each element present in the Earth’s crust, and extracting natural resources from these ores requires a large amount of energy. Therefore, this process becomes less sustainable as the Earth’s natural resources are being depleted.