Last month the City of Sydney declared that it had become Australia’s first carbon neutral government. It is important to note that whilst the total area of this southern metropolis is said to be equal to the size of London and nearly twice that of New York, at 4,000 square kilometres, the claim to carbon neutrality really only applies to the local government area called "Sydney." That spans the central business district and surrounding suburbs, and is about 26 square kilometres. But still, it's not a bad claim to fame.