Thomas K. Bauska and his team have been collecting chunks of ice from Antarctica. The air bubbles trapped in the ice have over 20 000 years and have been studied by scientists over the last thirty years. In the study led by Bauska, they measured the isotopic composition, that is, the amount and type of isotopes (atoms with a greater number of neutrons in their nucleus) present in the bubble air. With those measures, they were able to reconstruct a key indicator of the sources of atmospheric CO2, covering a period of time from 22,000 to 11,000 years ago. The results show that during the last deglaciation (a period going from an ice age to a warmer climate), there was a rapid increase in the CO2 concentration in the atmosphere.
Credit Thomas K. BauskaReferences
- Bauska, T. K., Baggenstos, D., Brook, E. J., Mix, A. C., Marcott, S. A., Petrenko, V. V., … & Lee, J. E. (2016) Carbon isotopes characterize rapid changes in atmospheric carbon dioxide during the last deglaciation. Proceedings of the National Academy of Sciencesr, 201513868.