New research suggests that massive volcanic eruptions in the Arctic created vast basalt fields that stripped carbon dioxide from the atmosphere. This process triggered the Sturtian glaciation, one of the longest ice ages in Earth's history. Unlike previous models, this study proposes that the ice age occurred in cycles. As glaciers retreated, fresh basalt was exposed, restarting the carbon removal process and plunging the planet back into a freeze multiple times over 56 million years.
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Interesting look at natural carbon sequestration. It is basically the same chemistry behind enhanced rock weathering projects we see today, just on a planetary scale over millions of years.
The scale is the key here. Modern carbon removal policies focus on megatons per year, but this shows how geological tipping points can lock in climate states for millions of years if the carbon sink is large enough.
The model is a simplified box model, so I wonder how much the actual rate of basalt exposure varied. If the cycles were uneven, the oxygen recharge periods might have been too short for some aerobic life to survive.
True, but the sedimentary layers in Australia and Svalbard seem to back up the cycling theory. It is better than the old theory of one long freeze that should have killed everything.
