Achieving Sustainability Carol Boyle Deputy Director International Centre for Sustainability Engineering and Research University of Auckland

Sustainability Ensuring the needs of the current generation are met without compromising the needs of future generations 4 generations = 100 years

Damascus - Over five thousand years old

Athens – nearly 7000 years old

Prague – 2000 years old

London – 2000 years old There are hundreds of cities over 1000 years old

Assumptions for the Future  Humans will be here  Current cities will be here  Food will still be grown  Materials and energy will still be required  Human basic needs will not have changed

1000 year Framework  Physical characteristics which define the limitations of the land ¥ Geology ¥ Topography ¥ Hydrology ¥ Climate ¥ Soil structure, quality, depth, regeneration ¥ Plate tectonics/seismology ¥ Proximity to coast

Constraints  Once we recognise the limits, this imposes some constraints or considerations on resource use  For example, availability of water will constrain population, industry and agriculture  While water can be brought in, it results in an economic and energy cost  This places a burden on future generations

Timeframes  The timeframes for management of resources needs to be identified  While some aspects must be managed on an annual basis, others must consider longer timeframes  Short, medium and long term aspects must be taken into account

Risk Based Future Thinking  How resources are managed affects the risk for future generations  Risk includes environmental, social and economic factors and is the cumulative probability of system failure over time  Risk can then be reduced through long term planning and management  System failure can be assumed when the system’s limits are exceeded

Sustainability  Thus the sustainability (S) over time is S T = 1-(  R T ) With R T = p(C>L | t = T) R T = Risk over time T L = System limit C = Consequences p = Probability

Systems Sustainability - Physical/Chemical  Includes hydrological, carbon, nutrient cycles, erosion, climate, energy systems, soil and rock formation  Operate on variety of timeframes and cycles which are interlinked  Climate change modelling has shown how complex the linkages between physical/chemical cycles are

Systems Sustainability - Environmental  Environmental systems are constantly changing due to both internal and external fluctuations  Some systems are years old usually characterised by: ¥ little growth of the dominant large species ¥ infrequent disturbances ¥ adequate land to buffer disturbances ¥ high biodiversity may provide resilience

Systems Sustainability - Environmental  The ability of an environmental system to withstand change depends on its resilience, vigour and diversity  Positive feedbacks amplify changes  Negative feedbacks provide major controls  Ecosystems however are complex, chaotic interactions of both negative and positive feedbacks

Systems Sustainability - Social  Human societies are highly varied  All are dependant on extraction of resources from environmental, physical and chemical systems  None provide a perfect example of effective government, economic distribution or equality

Systems Sustainability - Social  Tainter analysed the collapse of past societies and found four basic concepts: ¥ Human societies are problem-solving organisations; ¥ Sociopolitical systems require energy for their maintenance; ¥ Increased complexity carries with it increased costs per capita; and ¥ Investment as a problem-solving response reaches a point of declining marginal returns

Systems Sustainability - Social/Economic  Declining marginal returns can be seen in agriculture, mineral and energy production, education, health, management and productivity  As natural capital is depleted and ecosystems are degraded, the options available for recovering from change or disaster are reduced as only technical solutions will be available

Systems Sustainability - Social/Economic  To be sustainable the overall balance of activities within a society must ensure that maintenance, replacement and renewal equals or exceeds the processes of depreciation, degradation and loss  Sustainable products and services do not result in a sustainable society

Sustainability and Risk  Risk to current and future generations is increased when the solutions are: ¥ relatively new and untested ¥ complex ¥ reliant on resources which are in low supply ¥ reliant on systems which are controlled by those who have other agendas

Conclusions  A 1000 year scenario does not mean that change should not occur  It does mean that the limits posed by physical, chemical and environmental systems need to be understood and the risks of breaching those limits must be clarified

Conclusions  Both scientists and engineers have to identify the limits and risks of human activities  Paradigm shifts in economic thinking, technology design and what constitutes quality of life are needed  Recognising that societies will be here in 1000 years will help plan for that future

“…what now remains compared with what then existed is like the skeleton of a sick man, all the fat and soft earth having wasted away, and only the bare framework of the land being left…” Plato writing about Attica, 2,400 years ago