Sustainability refers to the ability of an organization, system, or process, to function effectively and perpetuate without depleting vital resources or negatively affecting its own environment to the extent that its existence is threatened.

Nature is probably one of the best examples of sustainability. Live organisms and lifeless matter coexist and thrive sustained primarily by one major source of energy – the Sun. Another source of energy and constant change is the hot core of the Earth. Critical to life on earth is the presence of water: in the atmosphere, in bodies of water and in our own bodies. Life on Earth is a nothing short of a miracle. Science is like a flashlight in the dark – the more we see in its light, the more we realize how little we know and understand. The Earth itself hangs in the delicate balance of forces of our solar system, our galaxy and the universe. If there is one lesson we should learn as we become more and more knowledgable of our world, the micro-cosmos and the macro-cosmos, is that EVERYTHING IS CONNECTED. Albert Einstein, in his Special Theory of Relativity, uses the term space-time continuum to suggest that space and time are not independent. Sustainability is about realizing that our actions today affect the present and the future of the continuum we are living in, the continuum of space, time, matter and life in which our children, grandchildren, and future generations of humans will live.

We build cities, we change the course of rivers, we drill and mine for resources, we cultivate the earth and we transport people and goods on roads and bridges, by ship or through the air. We produce and consume goods, and generate waste. Unlike any other species, a significant portion of the waste we generate is not bio-degradable and creates an imbalance in the extraordinary complex eco-system of our world. In the process of building a modern, civilized world, we are changing our environment by fast consuming nonrenewable energy resources, polluting the atmosphere and our waters and contaminating the soil.

How will our actions affect the future of humanity and the world as we know it? At the beginning of the 21st century the alarm signal is on. The voices of the scientists have been heard and governments, public agencies, industries and individuals make efforts to become more “green.” The reality of climate change keeps the conversation going despite the skepticism of few. The “carbon footprint” emerges as the unit of measure for sustainability. While the concept applies to environmental sustainability it should be clear that the sustainability involves not only the environment but also the social and economic aspects of human life. The paradigm of sustainability is illustrated below. To be sustainable is to achieve a balance between the social, economic and environmental aspects at play in the life of a community or society. Sustainability paradigm