Sydney’s ecological footprint - a size 11 problem?

Albert Dennis, spokesman for the Australian Population Institute, argues that Australia should have a' threshold' population of 30-50 million by 2050. Several prominent politicians appear to agree. The only way we can maintain the tax base and present a credible defence strategy, it has been argued, is to dramatically increase the number of souls living on this, the driest continent on earth. The aging population, the declining rate of reproduction, the sparseness of our population in our northern shores and the need to expand our economy (read: increase our consumption of manufactured goods) have all been highlighted as reasons justifying a dramatic increase in population numbers for Australia.

In contrast, many ecologists (Tim Flannery for one) argue we should have a population much smaller than we currently have – perhaps even as low as 8-12 million.

But how do we think about this problem rationally and with reference to the facts? Is there an overarching philosophy that can help us make some informed decisions about Australia’s sustainable population size?

The concept of the Ecological Footprint (EF) is the answer. What is an EF? Ecological footprinting is a way of understanding our impact on the Earth – it gives us a measure of how many resources we use to maintain our lifestyle. It requires information readily available to the public and to governments. How much energy (all forms) is used by people (and industry), how much food (and of what type) is consumed, how many resources are used in infrastructure (schools, roads, houses) and how many resources are being used to deal with all the waste produced (all forms, from the euphemistically named biosolids, to paper and food waste)? The beauty of the EF is that it can be calculated for individual houses, cities, States and entire countries. It is expressed as the amount of bioproductive land required to produce the food, wood, energy and other materials used in our daily life.

There are about 10 billion hectares of bioproductive land in the world. There are about 6 billion people on this earth. Therefore, everyone is entitled to about 1.7 hectares of this bioproductive land to support them. If you need much more, you are using someone else’s resources.

Some countries have an average EF of about half of one hectare. Some countries have an EF of about 13 hectares. The global average is almost 3 hectares. Energy consumption is a major determinant of the EF. Not surprisingly, the good ol’ US of A leads the world in energy consumption per person in the population. What is perhaps not well known is that Australia is the third largest consumer of energy (per person). Canada is second.

It comes as no surprise therefore, that the top three countries in the footprint stakes are – the good ol’ US of A, Canada and yes – Australia. Australia’s footprint is 7 –8 hectares – that is almost 3 times the global average.

What of Sydney itself? Sydney’s footprint is about 7 hectares. Therefore the population of Sydney requires about 26 million hectares of land to provide the food, water, energy and waste disposal for its population.

How does this help us think about Australia’s sustainable population size? It tells us that if we halve our energy consumption we will halve our footprint. If we want to have an EF more in line with the global average, we could halve our population size and do nothing to our rate of energy consumption (per person), or maintain our current population size and halve our rate of energy use. If we want to double our population to about 40 million we will have to consume one quarter of the energy we currently use (per person),. Personally, I really can’t see Australians consuming one quarter of our current energy use, given our predilection for maintaining households with 2 cars, 2 fridges and 3 TVs. No matter how well our economy may grow with an expanding population, our supplies of water, agricultural soil and fossil fuels remain limited. Time to think seriously about footprints and see if we can fit a size 6. We’ve stomped around for long enough in a size 11.