From my understanding Viper that is very much the case. As soon...

From my understanding Viper that is very much the case. As soon as you say coal it is straight away frowned upon. Not understanding that coking coal is a coal used for the production of steel from iron ore, there is not much of an alternative to get the temperatures required from other avenues that would be economical & viable.
Last year there was a shortage due to the Queensland flooding that stopped the coal trains delivering to the shipping ports. So supply is very much in demand & as you say sustainable.