Senator BIRMINGHAM (South Australia) (14:05): Mr President, I ask a supplementary question. Speaking of falsehoods, I refer the minister to this updated modelling and the assumption and all the modelled scenarios within it that 'Australia introduces a domestic carbon price in a world where other countries also act to mitigate climate change'. Does the government believe that other countries, particularly the United States and China, have policies in place that will ensure they comply with this assumption? If not, how quickly will they have such policies in place?