Kim Carr (Victoria, Australian Labor Party, Minister for Innovation, Industry, Science and Research) Share this | Hansard source

It is extremely unlikely that the warming that Australia has experienced can be explained by natural causes alone. The evidence is plain. Last year, the concentration of carbon dioxide in the atmosphere reached 386 parts per million. This is much higher than the natural range that has prevailed for at least 800,000 years. We are now more than 90 per cent certain that greenhouse gas emissions have caused most of the global warming since the middle of the 20th century. This is a very high level of certainty. How the Leader of the Opposition might wish that he could rely upon a 90 per cent certainty that Senator Joyce would get through the week without putting his foot in it!