The Cooling Ants

Can ants reduce atmospheric carbon dioxide?

Decrease in atmospheric carbon dioxide over geological time scales has been crucial in keeping the earth habitable for humans. Biotic organisms are one of the many factors that can lead to CO2 absorption from the atmosphere. Indeed, many geological studies state that without these biotic organisms earth today would be inhabitable for all organisms except for some primitive microbes (1). But which biotic organisms are responsible for this elixir of life? Plants, certain microbial species and termites have all been found to be involved in this carbon reduction process. However, the organisms which may surpass all others are…ANTSSSS.

Image courtesy: Kasi Metcalfe (Flickr)

After collecting carbon stock measurement in rocks for 25 years, a study found that natural CO2 absorption by rocks (containing calcium or magnesium) increased by ~335 times in ant presence than in ant absence (2). That is a significant impact specifically considering that there are trillions of ants living on earth. These results open up many exciting research questions and the mechanisms behind these ant effects are yet to be discovered? Can this ant-mineral interaction be utilised to reduce the impacts of global warming? Are some ant species more effective than others in enhancing CO2 absorption? Are there other effective species?

The irony here is that species such as ants which have played a key role in cooling our world and making life possible for us. It is these species which may themselves be negatively affected due to global warming. Studies predict that ants living in lower elevation in the tropics will face the strongest negative effects of global warming (3). Unfortunately these are also the places where the highest abundance and diversity of ants exist.

* Additional information: CO2 is absorbed from the atmosphere through the Urey reaction where calcium silicate (CaSiO3) or magnesium silicate (MgSiO3) react with the atmospheric CO2 and form calcium carbonate (CaCO3) or magnesium carbonate (MgCO3) respectively. As silicates form majority of the earths crust, it is no surprise that the Urey interactions commonly occur and continue to reduce CO2 on our planet.

References:

  1. Schwartzman DW. Life, Temperature, and the Earth: the self-organizing biosphere. 2002. New York, Columbia University Press. 272 pp.
  2. Dorn RI. Ants as a powerful biotic agent of olivine and plagioclase dissolution. Geology. 2014;42(9):771–4.
  3. Diamond SE, Sorger DM, Hulcr J, Pelini SL, Toro ID, Hirsch C, Oberg E, Dunn RR. Who likes it hot? A global analysis of the climatic, ecological, and evolutionary determinants of warming tolerance in ants. Global Change Biology. 2012 Feb 1;18(2):448–56.