Scientists show accelerating carbon dioxide release from rocks in Arctic Canada with global warming

10 October 2024

Researchers from the Department of Earth Sciences at the University of Oxford have shown that weathering of rocks in the Canadian Arctic will accelerate with rising temperatures, triggering a positive feedback loop that will release more and more CO₂ to the atmosphere. The findings have been published today in the journal Science Advances.

For sensitive regions like the Arctic, where surface air temperatures are warming nearly four times faster than the global average, it is particularly crucial to understand the potential contribution of atmospheric CO₂ from weathering. One pathway happens when certain minerals and rocks react with oxygen in the atmosphere, releasing CO₂ via a series of chemical reactions. For instance, the weathering of sulfide minerals (e.g., 'fool's gold') makes acid which causes CO₂ to release from other rock minerals that are found nearby. In Arctic permafrost, these minerals are being exposed as the ground thaws due to rising temperatures, which could act as a positive feedback loop to accelerate climate change.

Up to now, however, it has been largely unknown how this reaction will respond to temperature change and much extra CO₂ could be released.

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The results demonstrated that across the catchment, sulfate concentrations rose rapidly with temperature. During the past 60 years (from 1960 to 2020), sulfide weathering saw an increase of 45% as temperatures increased by 2.3°C. This highlights that CO₂ released by weathering could trigger a positive feedback loop that would accelerate warming in Arctic regions.

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