Volcanism spiked global temps during past hothouse

Roughly 56 million years ago, global temperatures rose 5 degrees Celsius within a few thousand years in an event called the Paleocene-Eocene Thermal Maximum (PETM). Scientists have often attributed the relatively rapid warming of the PETM — frequently used as an analogue for understanding modern warming trends — to large-scale biogenic methane emissions from seafloor reservoirs. But in a new study, researchers tracking carbon and boron isotopes preserved in the shells of tiny marine creatures called foraminifera, or forams, question the conventional wisdom, instead pointing to a volcanic source for the carbon emitted during the PETM.

Full content for EARTH is available to subscribers. If you would like to gain access to the full version of this article, as well as all EARTH content, please subscribe today.

If you are connecting using a Library (IP-based) Subscription, please access full issues of the magazine through our Library Access portal.

Mary Caperton Morton

Mary Caperton Morton

Morton (https://theblondecoyote.com/) is a freelance science and travel writer based in Big Sky, Mont., and an EARTH roving correspondent.  

Monday, December 25, 2017 - 06:00