A sustainable environment is a precondition for sustainable economic development. When an economy produces GDP by using energy and other inputs, the planet produces an invisible product, known as photosynthetic product of the planet (PPP) as a natural process. This PPP however contributes to the production of GDP as an invisible input. As GDP increases, there are adverse effects on the growth of PPP due to utilisation of environmental and natural resources. If degradation of the environment is not arrested and exhaustible natural resources are not conserved, the natural growth of PPP and consequently, future GDP growth will decline. In other words, the environmental cost of producing GDP will tend to increase, alongside the threats posed by global warming.
Shyam Nath, “Sustainable energy from renewable biological resources: The case of sugarcane bagasse”, in Workshop on energy efficiency, sustainability and societal change, University of California, Santa Barbara, USA, 2008.