Packaging plays its protective role in various ways. It was originally used to protect foodstuffs from natural hazards and help prevent them from deteriorating. With the rise of commercial society, packaging became portable. The industrialisation and mechanisation of food manufacturing in the 19th century sped up its development and production. In the 20th century, new materials (PVC, PET) were added to the long list of natural materials, such as wood, tinplate and aluminium.
International trade has increased greatly over the past few decades. Food now travels thousands of miles thanks to more efficient means of transportation, although these come at an environmental cost, measured in food miles (the amount of CO2 emitted per mile for a tonne of food). However, it is not only the journeys that are responsible for greenhouse gas emissions. Cultivation of crops and storage and processing of food all have an environmental impact too.