March 2021
Vol 7, Issue 13

About The Cover

Cover image expansion

ONLINE COVER Although the interglacial periods before the Mid-Brunhes Event (MBE), a climate shift that occurred more than 400,000 years ago, are considered to be cooler than those that came later, modeling and evidence from regional-scale studies at northern latitudes point to MBE climates warmer than those today. These global and regional inconsistencies have been difficult to reconcile due to a lack of paleoclimate records with clearly defined dates. To investigate what ancient northern climates may have been like before the MBE, Moseley et al. used uranium-series dating to calculate the age of a 12-centimeter-thick sample of flowstone collected from a cave during a 2015 expedition to northeast Greenland. Their findings suggest that the Arctic was at least 3.5°C warmer than today during an interglacial warming event between 588 and 549 thousand years ago, even though Earth's global climate was cooler at the time. The study may inform researchers' understanding of how the Arctic responds to modern-day climate change, demonstrating that the Arctic heats up much faster than the rest of the Earth during periods of global warming. [CREDIT: ROBBIE SHONE]