CLIMATE WATCH - Carbon Burps in the Geological Record

"Carbon Burps" ?? What are Carbon Burps?


They are sudden releases of carbon from ancient rocks.

They show up in the geological record as changes in geochemistry (so they are found by using fairly complex laboratory tests on rocks)

They are associated with extinction events, but the scale of extinction varies a lot.



The most extreme geological example of events like this is the end-Permian, when igneous activity broke through coal seams in Siberia.

The interaction of hot magma and coal produced lots of CO2.

The end-Permian event reduced oceanic biodiversity by about 92%.

Recovery of biodiversity took about 10 million years - the fossil record from the next part of geological time, the early Triassic, is very thin.

Messing with planetary systems isn't wise.

One event with possibly closer similarities to what we are doing was about 56 million years ago, the Palaeocene-Eocene Thermal Maximum.

The PETM mechanism (according to some good research) involved volcanic action breaking through carbon-rich sedimentary deposits.

This was related to the rifting that produced the North Atlantic, and we see some of the results of that volcanic activity in eg the Giant's Causeway, Arran, Skye, Mull, Ardnamrchan, Rhum.......




The interaction of hot magma with the sediments produced vast amounts of CO2 - a kind of natural parallel with our activities. But it took many thousands of years.....that's the very dangerous difference this time, the rate of change.

Life will survive, but human societies depend on climatic stability for food supplies - that's the weakest link in all this.




After the PETM, it took around 20 million years for CO2 levels to fall sufficiently for glaciation to begin in Antarctica, at the Eocene-Oligocene transition.

The CO2 was mainly taken up by weathering of the newly-rising Himalayas - when large mountain chains are formed they experience slow chemical weathering and this slowly reduces atmospheric CO2, cooling the Earth.

CO2 in rain makes a weak acid, which causes the chemical weathering.

Rivers carry the carbon compounds down to the oceans, where various processes (such as the formation of calcareous shells by organisms) eventually deposit the material on the ocean floor.

This is the long, slow, part of the carbon cycle.

(Scientific source ......"Terrestrial cooling in Northern Europe during the Eocene–Oligocene transition" - Hrena et al, 2013)

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