The Glacial‐Interglacial CO 2 ‐Temperature Relationship

作者：B. B. Cael, Gavin L. Foster, Jonathan M. Gregory, Malte F. Jansen, Matthew Osman, Jessica E. Tierney · 发表于：Geophysical Research Letters · 年份：2026 · DOI：10.1029/2025gl121070 · 研究领域：Geology and Paleoclimatology Research、Climate change and permafrost、Paleontology and Stratigraphy of Fossils

Abstract The slope of the global mean surface temperature (GMST)–atmospheric carbon dioxide () relationship, sometimes termed Earth system sensitivity, is a holistic measure of Earth's response to radiative forcings. We identify a surprising trend in over the past 800 kyr, when it reflects the net carbon cycle feedback's response to GMST changes. We estimate roughly doubled over this period. This trend is robust to record completeness and reported age error, and across multiple GMST reconstructions and proxy types. Paradoxically, however, site‐specific records do not show increasing temperature variability relative to . This implies either age errors are substantially underestimated, or local variations in temperature became more synchronized over the more recent glacial‐interglacial cycles, possibly via either a strengthening ice‐albedo feedback or phase locking and spatially variable carbon cycle feedbacks.