It is bullshit. Former Snowy Hydro boss Paul Broad is far from alone in his expert, if refreshingly colloquial, view that Australia’s farcical state, federal and corporate greenhouse gas emissions targets are simply unattainable – and never were. And now, the head of the world’s second-biggest miner, Rio Tinto, says his company’s scope 1 and 2 emissions targets were a mistake – and he won’t join rivals BHP, Vale, Glencore and Fortescue (with its ambitious net zero by 2040) in pretending he can set achievable targets for the scope 3 emissions of Rio’s overseas customers, over which Rio has no...