Opposition Leader Tony Abbott's depiction of carbon trading as a whole bunch of nothing has revealed a whole bunch of something he has mostly kept hidden.

''Just ask yourself,'' Abbott said, his frustration bubbling to the surface, ''what an emission trading scheme is all about, it's a market, a so-called market, in the non-delivery of an invisible substance, to no one.''

It was a reductio ad absurdum, which runs counter to the message Liberals have been pushing for years, particularly to younger voters - that climate change is real, that it is human induced, and that the conservatives are genuine about addressing it.