Senator BOB BROWN (Tasmania—Leader of the Australian Greens) (14:21): My question is to the Minister representing the Minister for Climate Change and Energy Efficiency. Is the minister aware of the letter from the Prime Minister of the UK to our Prime Minister, Julia Gillard, in reference to the carbon package saying: Your announcement sends a strong and clear signal that Australia is determined to make its contribution to addressing this challenge and it will add momentum to those in both the developed and the developing world. Honourable senators interjecting— The PRESIDENT: Senator Brown is entitled to be heard in silence. Senator BOB BROWN: Mr Cameron went on to say: Your action will add momentum to those, in both the developed and developing world, who are serious about dealing with this urgent threat. Honourable senators interjecting— The PRESIDENT: If this is the way you wish to waste the time of question time, then that is your choice. But I am entitled to hear the question and Senator Brown is entitled to be heard in silence. Senator Brown, continue. Senator BOB BROWN: I ask the minister: is it not an embarrassment that Australia has a Leader of the Opposition, a conservative, in London, who, to take the Prime Minister of Britain's words, is neither serious about action on climate change nor prepared to have Australia play its role in contributing to addressing that challenge?