From: David Karoly Date: Thu, 26 May 2011 06:55:53 +1000 To: Paul Christenson Conversation: Alan Jones program Subject: Re: Alan Jones program

Hi Paul,

Thanks for the opportunity to participate in the Alan Jones show yesterday morning.

I would be grateful if you or Alan could correct two mistakes.

First, the podcast link for my interview labels me as a advocate. That is a mistake. I do not advocate for climate change. I am a climate change scientist. Please change that on the web site.

Second, I made a mistake and Alan Jones made a mistake with the maths that he did quickly at the start of the interview. He correctly said that CO2 is 0.04% of the atmosphere. He correctly said that human emissions of CO2 are about 3% of the annual fluxes of CO2 into the atmosphere. He correctly said that Australian emissions are about 1.5% of the 3%, or about 0.045% of the total annual production of CO2 going into or out of the atmosphere. He then made a series of mistakes. It is a mistake to multiply the first number 0.04% by the last number 0.045% to try to get the Australian contribution to actual CO2 in the atmosphere.

The actual number for the Australian contribution to CO2 in the atmosphere is 1.5% of the anthropogenic increase in CO2 in the atmosphere, 30% of the total, so that 0.45% of the total CO2 in the atmosphere is due to Australians. This has to be multiplied by 0.04% to give the Australian CO2 as a total fraction of the atmosphere, which is 0.00018%. This is still a small number, but it has a lot less zeroes than Alan said.

It was a mistake for me to agree with Alan on those numbers, as I didn’t have time to do the calculations in my head. I am happy to admit I made a mistake.

Given Alan’s obvious interest in the interview to get the numbers correct, and confirmed by me, I am sure that he will be keen to admit his mistake on air and give a correction.

Best wishes, David

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Prof David Karoly School of Earth Sciences University of , VIC 3010, ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~