Planetary Boundaries: Are we pushing our planet off the cliff?

by Terence Jeyaretnam

Everything that we know has limits, whether they relate to physical, psychological or capital stocks. Stocks need to be replenished; assets maintained; brains rested for them to keep going, except perhaps one quite relevant phenomenon, human stupidity, according to French novelist Gustave Flaubert, who once proclaimed "earth has its boundaries, but human stupidity is limitless".

The notion that the Earth has limits has only been around for a relatively short time, which is surprising, yet understandable. A pre-1970’s world population of under 4 billion people wasn’t enough to stress test Earth’s capacity. Furthermore, economics as a discipline is dominated by the notion of an unlimited world with unlimited resources. Limits to Growth by the Club of Rome in 1972, was the first comprehensive research publication to show that human impact on Earth was going to reach planetary boundaries within decades under business as usual scenarios. It presented a model in which five variables: world population, industrialization, pollution, food production, and resources depletion, were examined along with technology, under three scenarios. Two of the three scenarios saw the models crash through a collapse due to exceeding planetary boundaries.

More recently, the notion of planetary boundaries has emerged, which is the central concept in an Earth system framework, proposed by a group of scientists, including Will Steffen from our own Australian National University, designed to define a “safe operating space for humanity”. The group identified nine planetary life support systems – climate change, land use, biodiversity loss, freshwater use, phosphorus cycle, nitrogen cycle, ozone depletion and ocean acidification. According to the authors, since the industrial revolution the planet has entered a new epoch, out of Holocene into the Anthropocene. In the Anthropocene, humans have become the main agents of change to the Earth system.

Limits to Growth and planetary boundaries both represent starting points in defining critical limits. There’s much more research to do, and science to be refined. What concerns me is the lack of resources dedicated by nations to better crystalise nations’ and planet’s carrying capacity so that economic theory through to global and state policies could be based on a notion of safe operating limits.

Sources: Rockström, J; Steffen, WL; and 26 others (2009), "Planetary Boundaries: Exploring the Safe Operating Space for Humanity", Ecology and Society 14 (2): 3 and Steffen, W.; Rockström, J.; Costanza, R. (May 2011), "How Defining Planetary Boundaries Can Transform Our Approach to Growth", Solutions 2 (3)

Terence Jeyaretnam is a Director of Net Balance (, 
one of the world’s leading sustainability advisory firms.
Terence is based in Melbourne.

Twitter: TerenceJey

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