Here’s a link to a PDF which explains that 4.2 tons pa per person is the optimum amount of carbon emitted. http://www.optimumpopulation.org/optjournal/opt.af.biocapacity.PDF
Here is the salient quote, “The constraint that the use of energy places on population is simple in global terms. The Earth’s carbon sinks are able to absorb about 9 billion tonnes of carbon dioxide a year, from the burning of fossil fuels. A probable mean lowest acceptable carbon dioxide emission is 4.2 tonnes per person per year.” 🙂
In 2009 Australians produced 19.6 tonnes per person pa, the outright worst in the world: https://spreadsheets.google.com/ccc?key=0AonYZs4MzlZbdFF1QW00ckYzOG0yWkZqcUhnNDVlSWc&hl=en#gid=0
I’ve got mine down to about 6 tonnes pa. However, owning a car and going on a couple of aeroplane trips in the past year blew my figure out but I’m getting there. 🙂
