Mr President, I have a supplementary question and I wonder if the minister can respond to it directly. Given that some states in the US were supposedly able to achieve a 23 per cent reduction in emissions with a $2 a tonne price on carbon, why is it that under Labor's $23 a tonne carbon tax, the biggest carbon tax in the world, domestic emissions are expected to increase from 578 million tonnes of carbon dioxide in 2010 to 621 million tonnes of carbon dioxide in 2020?