Supply - and demand !

Australia has encountered a lot of criticism because it is the world's largest supplier of coal - and coal is a prime source of carbon pollution.

There are calls for coal exports to be curbed - and protests against new coal mines being established, but all this tends to run counter to the rules that apply to a basic tenet of commerce - the laws of supply and demand.

Without demand, there is no reason for supply to exist. It is a fact of life that the cheapest way to generate electricity in the quantities needed to light cities and drive industry is to burn coal.

If Australia reduced the supply of this commodity two things would happen. New mines would immediately appear in other countries to meet this demand - and the price of coal would increase because of the scarcity.

The only way coal use will be reduced for power generation is when science develops a better method that can reliably deliver the quantities needed at somewhere near the cost of burning coal - and so far that is a distant dream.

Work is in progress on everything from " hot rocks " deep in the earth to wave action, wind and solar - and steady progress is being made. In the interim, it is senseless to blame Australia for obeying a law of nature.

While demand exists - supply will follow !