The challenge facing the world economy today is to provide sustainable approaches to economic growth. Industrial processes have the potential to provide better living standards, improved education and health care. However, careless industrialisation can lead to negative development, such as pollution - a difficult and expensive problem to solve, which can often lead to the quality of living standards falling. One drawback of industrial processes is the creation of waste products. These waste products enter a ‘sink’ which can sometimes ‘overflow’, harming the environment so that the wider resource base may be depleted.