15 December 2015

Deforestation has same 'fingerprint' as fossil fuel combustion

Several climate metrics are claimed to be fingerprints showing that human fossil fuel combustion caused the recent atmospheric carbon dioxide rise [1, 2]. These are:

1) Rising CO2 and falling oxygen
2) Falling 13C/12C ratio
3) CO2 is highest in ~800,000 years

04 December 2015

Decline in 13C/12C ratio not keeping pace with fossil fuel combustion emissions

One of the key "fingerprints" of human influence in the rise of atmospheric carbon dioxide is the declination in d13C, the ratio between 13C/12C.

Fossil fuels are supposed to have more of the carbon-12 isotope in comparison to the carbon-13 isotope compared to what's "average" in the atmosphere prior to burning. Hence burning fossil fuels should decrease the 13C/12C ratio. And this is what's found.

But while human emissions of CO2 from fossil fuel combustion are only increasing with time (you should see what China's doing)...