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Continental arc volcanism as the principal driver of icehouse-greenhouse variability

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Science  22 Apr 2016:
Vol. 352, Issue 6284, pp. 444-447
DOI: 10.1126/science.aad5787

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Erosion overwhelmed by eruption

Volcanism and erosion can feed into long-term climate change, but determining their relative importance is challenging. Erosion is known to be a carbon sink and is thought to play an outsized role in shifting global climate. However, McKenzie et al. suggest that long-term oscillations in climate may be tied to the amount of continental arc volcanism (see the Perspective by Kump). A global compilation of arc volcano-produced zircons over the past 700 million years revealed good correlation between warm and cool epochs with the waxing and waning of volcanism. Thus, volcanism may be a more important driver and erosion a less important sink for very long-term climate changes.

Science, this issue p. 444; see also p. 411

Abstract

Variations in continental volcanic arc emissions have the potential to control atmospheric carbon dioxide (CO2) levels and climate change on multimillion-year time scales. Here we present a compilation of ~120,000 detrital zircon uranium-lead (U-Pb) ages from global sedimentary deposits as a proxy to track the spatial distribution of continental magmatic arc systems from the Cryogenian period to the present. These data demonstrate a direct relationship between global arc activity and major climate shifts: Widespread continental arcs correspond with prominent early Paleozoic and Mesozoic greenhouse climates, whereas reduced continental arc activity corresponds with icehouse climates of the Cryogenian, Late Ordovician, late Paleozoic, and Cenozoic. This persistent coupled behavior provides evidence that continental volcanic outgassing drove long-term shifts in atmospheric CO2 levels over the past ~720 million years.

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