Shorten doubts the tax he says we need John Howard this week confessed he just gave in to fearmongers when he agreed to a carbon tax, and he never really believed in catastrophic warming. Turns out another leader is also a private doubter - at least of the tax: Privately Shorten was a staunch opponent of the carbon tax. He did not believe it should have been Labor policy. If every politician who privately doubts either catastrophic man-made warming or a carbon tax spoke up, the debate would be instantly changed. Instead, they keep silent, thinking that everyone else's silence shows the believers are too many to be defied.