Senator BIRMINGHAM (South Australia) (14:39): Mr President, I ask a further supplementary question. Given that the government introduced a carbon tax despite promising not to do so, axed its floor price of that carbon tax despite saying that a floor price was central to certainty and signed on to a second commitment period under Kyoto despite putting in previous submissions that doing so was conditional upon legally binding action by all major economies, how can anything this government says about climate change policies actually be believed? Government senators interjecting— The PRESIDENT: Order! I remind senators on both sides that the time to debate this is after three o'clock.