Vor einigen tausend Jahren: Pazifik erwärmte sich innerhalb von nur zwei Jahrhunderten um mehr als 2 Grad

Publikation von Bova et al. 2016 in den Geophysical Research Letters:

Rapid variations in deep ocean temperature detected in the Holocene

The observational record of deep ocean variability is short, which makes it difficult to attribute the recent rise in deep ocean temperatures to anthropogenic forcing. Here we test a new proxy—the oxygen isotopic signature of individual benthic foraminifera—to detect rapid (i.e., monthly to decadal) variations in deep ocean temperature and salinity in the sedimentary record. We apply this technique at 1000 m water depth in the Eastern Equatorial Pacific during seven 200 year Holocene intervals. Variability in foraminifer δ18O over the past 200 years is below the detection limit, but δ18O signatures from two mid‐Holocene intervals indicate temperature swings >2°C within 200 years. More vigorous transport between the surface and deep ocean or stronger eddy variability than that observed in the historical record are potential explanations. Distinguishing externally forced climate trends in deep ocean properties from unforced variability should be possible with systematic analysis of suitable deep sea cores.