Humanity’s recent development has occurred primarily because of its ability to convert environmental assets into manufactured assets. Converting a forested area into farmland or extracting oil from the ground to convert into plastics, make for common examples. Economist Robert Solow coined the term weak sustainability to summarise this course of action. Weak sustainability is the concept that natural capital can be substituted for manufactured capital. Alternate to this is strong sustainability, which states manufactured capital and natural capital are complementary but not interchangeable, because natural capital must be maintained and enhanced as it performs functions that cannot be duplicated by manufactured capital e.g. pollination, rainfall and climate regulation. Humanity has exercised the first concept intensively whilst populating the globe; converting wilderness into farmland, ranches and urban spaces. As a species we have been ruthlessly efficient at this, so much so that in our 12,000 year history as agronomists, we have left only 22% of the world’s old growth forests intact.