The up and coming paper with all the graphs will be released in about six weeks.

oxygen isotopic ratios in the dating of ice cores-40

nikki hilton dating - Oxygen isotopic ratios in the dating of ice cores

Plants are ‘deficient’ in C13, and so, then, ought to be our fossil fuel derived CO2. We are 5.5 and plants are putting 121.6 into the air each year (not counting ocean plants).

The implication is that since coal and oil were from plants, that “plant signature” means “human via fossil fuels”. There is a lot of carbon slopping back and forth between sinks and sources.

Some years from January to January there may be a rise of 0 ppmv (ie no change), some years up to 3 ppmv.

If those changes were due to man-made CO2 then we should see more of those rapid increases in recent times as man-made emissions increased faster.

Instead the sources appear to be in places like the Amazon Basin, southeast Asia, and tropical Africa — not so much the places with large human emissions of CO2!

But CO2 is a well mixed gas so it’s not possible to definitively sort out the sources or sinks with CO2 measurements around the globe. Instead the way to unravel the puzzle is to look at the one long recording we have (at Mauna Loa, in Hawaii, going back to 1959) and graph the changes in CO2 and in C13 from year to year.

Word reached the Sydney Institute, which rushed to arrange for him to speak, given the importance of this work in the current Australian political climate.

The ratio of C13 to C12 (two isotopes of carbon) in our atmosphere has been declining, which is usually viewed as a signature of man-made CO2 emissions.

Salby says he sat on the results for six months wondering if there was any other interpretation he could arrive at, and then, when he invited scientists he trusted and admired to comment on the paper, they also sat on it for half a year.