I don’t try and hide it, I love radiocarbon. It has so many applications, how can you not love radiocarbon as an Earth Scientist? This time my beloved carbon isotope is in the news as it is being used to answer one of the more fundamental questions of climate change: How can we best measure CO2 emissions from the burning of fossil fuels? A rather important calculation if we want to verify emissions targets.
The report in Science last week covered findings that were presented at the Radiocarbon Conference in Paris earlier this month. Here scientists discussed how measuring the proportion of atmospheric CO2 that is labelled with radiocarbon, a.k.a carbon 14, could be the best way to attribute CO2 to fossil fuels.
At natural abundance, only one in around one trillion molecules of CO2 (1:1,000,000,000,000) contain radiocarbon. However when we burn fossil fuels we load the atmosphere with carbon dioxide that has no radiocarbon in it all. This is because fossil fuels are formed by reserves of ancient organic matter (think plants…and dinosaurs if you watch old Leslie Neilson movies*). Because radiocarbon has a relatively short half-life (5730 years), it has all decayed away by the time we get around to burning these ancient carbon stores. Therefore scientists, and people paying carbon taxes, should be very interested in increasing CO2 concentrations, and the relative decreasing concentration of radiocarbon in the atmosphere.
Measuring less than not very much is no trivial matter, and is why we rely on people like my supervisor, Dr Stewart Fallon, who is adept at running our instrument that is dedicated to measuring radiocarbon, the Accelerator Mass Spectrometer. I’m in the process of learning the instrument, but I have mastered producing a very, very small sample that we can get reliable numbers from. I’m thinking of getting us super hero capes; but that might just be because it’s very late in the day, and I should know better than to write posts when I ‘m giddy…
See the sensible article if you can access Science, here.
* – “Jacobs, I want to know absolutely everything that’s happened up till now”.
– “Well, let’s see. First the earth cooled. And then the dinosaurs came, but they got too big and fat, so they all died and they turned into oil…”
Flying High II (1982)