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Climate Change – and the Sustainability Emergency

If we fail to tackle our climate crisis, it could be a turning point in human affairs that is so radical it would be almost impossible for us to imagine the lives of those who are affected. We could enter a world where nothing humanity has taken for granted for the last 10,000 years can be relied upon.

The extensive melting of Arctic sea-ice in the northern summer of 2007 clearly represents dangerous climate change, both more rapidly and at lower global temperature increases than previously projected.  The tipping point for this event was around two decades ago when temperatures were about 0.3°C lower than today. The loss in summer of all eight million square kilometres of Arctic sea-ice now seems inevitable, and may occur as early as 2010, a century ahead of the projections by the Intergovernmental Panel on Climate Change (IPCC).

We sometimes imagine that climate change may procede gradually, but that ignores the fact that the climate is a complex system.  Such systems have a number of stable states, and can move from one to the other not gradually but by sudden jumps.  These stable states are the “multiple equilibria” of the system.  Think of a beach ball that has rolled into a hollow between some sand dunes.  A gentle kick does not get the ball out of the hollow, it just rolls back down to the bottom.  However, a strong kick will knock the ball over the top of the dune and perhaps into the hollow next door.  The sandy hollows represent the multiple equilibria of the system and, just like the beach ball in a sandy hollow, a complex system can be resistant to further change once it arrives at a new equilibrium.  By increasing the level of CO2 a pre-industrial level of 280 ppm to over 385 ppm today this is the experiment we are now playing with the climate and we have no idea what the next equilibrium could represent for us or the rest of life on Earth.

A series of critical thresholds have been identified which, if crossed, could accelerate the onset of an era of dangerous climate change which  humanity will no longer have the capacity to reverse.  We would simply have to adapt to the consequences as best we can.

As more evidence is gathered it is becoming widely recognised that a temperature rise cap of 2°C, as proposed within the United Nations framework, would take the planet’s climate beyond the temperature range of the last million years and into catastrophe. The evidence has been building that we simply cannot add more carbon dioxide to the atmosphere and that we need to achieve this within a very short time frame.  One of the world’s leading climate scientists, James Hansen of the Goddard Institute at NASA and his colleagues, stated recently that:

“Humanity today, collectively, must face the uncomfortable fact that industrial civilization itself has become the principal driver of global climate. If we stay our present course, using fossil fuels to feed a growing appetite for energy-intensive life styles, we will soon leave the climate of the Holocene, the world of human history. The eventual response to doubling pre-industrial atmospheric CO2 likely would be a nearly ice-free planet. ...

Paleoclimate evidence and ongoing global changes imply that today’s CO2, about 385 ppm, is already too high to maintain the climate to which humanity, wildlife, and the rest of the biosphere are adapted.” (click here for the full summary).

They  suggest an initial objective of reducing atmospheric CO2 to 350 ppm, with the target to be adjusted as scientific understanding and empirical evidence of climate effects accumulate. This target must be pursued on a timescale of decades, as paleoclimate and ongoing changes, and the ocean response time, suggest that it would be foolhardy to allow CO2 to stay in the dangerous zone for centuries.  In practical terms, this will mean eliminating human greenhouse gas emissions, taking massive amounts of excess CO2 out of the air in order to restore the reflectivity of the Earth’s surface (with clouds and ice being the strongest influences) while maintaining adequate supplies of affordable food and securing the survival of the world’s biodiversity.

The challenge is great, but time is short - climate change does not send a price signal which markets can respond to, nor will the climate crisis be solved by incremental modification of the business-as-usual model. This means that we need to redefine the debate as a sustainability emergency that requires actions far beyond the imagination of current business and politics if we wish to create a realistic path back to a safe-climate world.    

In reality, most of the needed actions are things we should be doing anyway.  Given the fact that fossil fuels are limited in quantity and that we are already in view of the global peaks in oil, natural gas and coal, we must transition to a future which is less dependent on fossil fuel.  It will require unprecedented creativity at all levels of society but in a hundred years from now, whether or not we act, industrial society will have radically changed. What we do now, however, will determine whether those future generations live in an impoverished and unpredictable world, or one that is in the process of being renewed and replenished.