If the society toward which we are developing is not to be a nightmare of exhaustion, we must use the interlude of the present era to develop a new technology which is based on a circular flow of materials such that the only sources of man's provisions will be his own waste products. Kenneth Boulding
Human activity is having a major impact on the planet. We consume or have diverted a large proportion of the productivity of the land and oceans. Our hunger for land crowds out fellow species. Our waste products pollute the waters, warm the atmosphere and acidify the oceans. Ian Goldin