Actually, we can trace the presence of sustainability till the earliest civilizations. According to archeologists the sustainability of past civilization resulted in the ability to resolve arise problems and overcome decline and being able to maintain their needs at the same time. In other words, sustainable decisions were a way to prosperous and long existence for our ancestors (1).
The industrial revolution forced the modern society to rely more and more on fossil fuels, because more powerful machines were needed to satisfy the growing demands of the population. This is when the first responses to an increased level of air pollution occurred and initiated the so called ‘environmental movement’. In the middle of the 20th century this movement brought to the light the concerns about the undefined environmental costs of some innovative materials, such as plastics, nuclear energy, pesticides, etc. Since then more and more environmental problems were being looked at. In the report “Our common Future” from 1987 Brundtland Commission used the term sustainable development. This is the most quoted definition of sustainable development: "development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”(2) In the beginning of the 21st century the awareness of the harmful effect of our society has reached global scale. Topics about renewable energy sources, greenhouse effect, urban island effect and many more are not new to us anymore.
Regarding the question about the “age” of sustainability, I would probably state, that sustainability is not new, because being unsustainable leads only to decline. Maybe our approach of today towards sustainability is more scientific and technology based and previous civilizations were sustainable more on the intuitive level. Therefore, it doesn’t matter how it was called or to what extend sustainability existed in human-beings daily lives, because being sustainable is the only way towards the future.
The Origins of sustainability (http://www.webpages.uidaho.edu/sustainability/chapters/ch01/ch01-p01.asp), retrieved on 20-11-2014
United Nations, ‘Report of the World Commission on Environment and Development.’ General Assembly Resolution 42/187, 11 December 1987.