One Nation senator Malcolm Roberts is yet to be convinced that climate change is real and is caused by humans.
He has asked chief scientist Dr Alan Finkel to spell out his logic in asserting that human-induced carbon emissions have been rising since the start of the Industrial Age, that this causes global warming and that warming produces climate change.
Senator Roberts told a Senate committee on Thursday his requested summary of the logic and the empirical evidence behind climate change did not need to be long: "like me - short and simple".
In September Senator Roberts sought to meet CSIRO scientists to see if they could convince him there was proof of human-related climate change.
Dr Finkel said it was established in 1896 that the more CO2 in the atmosphere, the more heat was trapped.
It had also been established that atmospheric CO2 levels had been rising measurably from human activity since the start of the industrial age and that global temperature was rising.
The effect of warming on climate wasn't clear.
"We have models to try to predict what that will be and that's difficult," Dr Finkel said, adding that models did predict significant climate change.
Senator Roberts requested the chief scientist to provide him with a summary of the logic and evidence at each stage.
"It doesn't have to be long. I just want to check the logic and the data," he said.
