Monday, November 5, 2007

Good on him!

Dr Karl has issued a correction. Let's hope it gets as much media coverage as the original statement!

Sunday, November 4, 2007

My run of luck ends

I was 4/4 for letters to major newspapers over the last couple of years. (Finding these is left as a Googling exercise for the reader). This time I have had a go at Dr Karl, and my letter has passed into limbo.

In this article in the Sydney Morning Herald on Friday, Dr Karl is quoted as claiming that Sydney produces a cubic kilometer of carbon dioxide every day, and that this makes carbon capture technologies ‘impossible’. Ignoring the dictum that the first person to mention the Nazis in an argument loses, he cites ‘clean coal’ as an example of Goebbels’ ‘big lie’.

Back in May we were told that Australians produce ‘more than five’ tonnes of carbon per capita per annum. That is, more than 18 tonnes of carbon dioxide per capita per annum.

This other site indicates that total Australian greenhouse gas emissions are of the order of 600 million tonnes of carbon dioxide per annum.

Thus, we can guess at 20-30 tonnes of carbon dioxide per capita per annum in Australia.

This gives 80-120 million tonnes of carbon dioxide per annum in Sydney.

This is 1.8-2.7 trillion moles of carbon dioxide.

Which is 40-60 trillion (1012) litres of carbon dioxide at atmospheric pressure.

Which is admittedly a lot.

There are a trillion litres in a cubic kilometre.

So, we have 40-60 cubic kilometres of uncompressed carbon dioxide per annum. That is more like one a week, not one a day.

Week, day, whatever. Near enough is good enough, as my uncle who builds space probes for NASA says.

The article claims that Sydney would produce a cubic kilometre of ‘compressed’ carbon dioxide per day. I don’t think Dr Karl would have said this, because it sounds too silly.

One mole of carbon dioxide at atmospheric pressure will occupy 22.4 litres. By pV= nRT, if we put it under a pressure of 100 atmospheres, it will occupy near enough to 1% of that. I don’t know what sort of pressure is appropriate for the zeroth-order ‘pumping it into empty oil and gas reservoirs’ sort of carbon capture technology. But I do know that the grail of this sort of thing is converting carbon dioxide into a solid.

One mole of carbon dioxide converted into, say, calcium carbonate, will occupy 37 cubic centimetres.

So, rather than ‘one cubic kilometre per day’ we have 0.10-0.15 cubic kilometres per day, which could be theoretically converted into 0.0002-0.0003 cubic kilometres of calcium carbonate per day. That would be about 20 times as much as the solid waste currently produced by Sydney per day. So it is still a lot. But, for the love of God, calling it a ‘big lie’ is a bit rich.

Here is how I ended my letter:

‘The fact that many different people are working on many different strategies to solve a problem should be a source of optimism and joy. That a group called the Climate Change Coalition would malign the motives of researchers pursuing carbon sequestration technologies is depressing, to say the least.’