Carbon-14 dating and Climate Breakdown

This is one of many topics that would not have been on the list of things to find out about before being prompted by climate breakdown.

https://skeptoid.com/episodes/4549

The first part of this audio and transcript from 2016 meant a quick foray into the world of carbon-14 and carbon-12.

When cosmic particles like protons, alpha particles, etc enter the earth's atmosphere, they occasionally collide with atoms to produce neutrons that can then collide with nitrogen-14 atoms (78% of atmosphere) to produce carbon-14 atoms, which are one of the isotopes of carbon.

Carbon-14 atoms have 6 protons and 8 neutrons as opposed to carbon-12 atoms which have 6 protons and 6 neutrons. Carbon-14 atoms are radioactive, with a half-life of about 5730 years. Their rate of creation varies over time, but can be calibrated using fossil tree rings, stalactites, stalagmites, etc.

The ratio of carbon-14 to carbon-12 atoms can be measured, and with calibration, can be used to say how old an organic object with carbon is, because once that object is no longer living, the carbon-14 starts to decay.

Carbon dating is useful for remains up to about 50-60,000 years old, because objects older than that have no carbon-14 left because sufficient half-life periods have elapsed.

Fossil fuels will have zero carbon-14 in them, so when burned, the CO2 produced will have only carbon-12 atoms, without any carbon-14.


The extract above together with the understanding of carbon-14 can be summarised as a set of annual emissions of CO2 in millions of tons, in 2016:
  • volcanic activity 200 million tons CO2 (carbon 12 only)
  • total 29 billion tons CO2 (carbon 12 only)
  • forest fires will create a mixture of carbon 12 and carbon 14 atoms
  • Nearly 29 billion tons CO2 produced by human burning of fossil fuels
  • The obvious point is that these changes affect the current ratio of carbon 12 to carbon 14 which will make life very difficult for the archaeologists of the future, with the obvious assumption.
More science on carbon dating:
http://www.whoi.edu/nosams/page.do?pid=40138

And the carbon cycle, slow and fast:
https://earthobservatory.nasa.gov/features/CarbonCycle/page1.php

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