Abrupt climate change

An alternative view

Bibliographic Data

ID24086242
AuthorsCarl Wunsch (0000-0001-6808-3664, Massachusetts Institute of Technology, corresponding author)
Year2006
Volume65
Issue02
Pages191-203
Publication date2006-03-01
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueQuaternary Research (JOURNAL)
Journal identifiersISSN: 0033-5894 • E-ISSN: 1096-0287
PublisherCambridge University Press (CUP) (PUBLISHER)
DOI10.1016/j.yqres.2005.10.006
OpenAlexW2149926282
LanguageEN
Citations received12
References cited53

Hypotheses and inferences concerning the nature of abrupt climate change, exemplified by the Dansgaard–Oeschger (D–O) events, are reviewed. There is little concrete evidence that these events are more than a regional Greenland phenomenon. The partial coherence of ice core δ 18 O and CH 4 is a possible exception. Claims, however, of D–O presence in most remote locations cannot be distinguished from the hypothesis that many regions are just exhibiting temporal variability in climate proxies with approximately similar frequency content. Further suggestions that D–O events in Greenland are generated by shifts in the North Atlantic ocean circulation seem highly implausible, given the weak contribution of the high latitude ocean to the meridional flux of heat. A more likely scenario is that changes in the ocean circulation are a consequence of wind shifts. The disappearance of D–O events in the Holocene coincides with the disappearance also of the Laurentide and Fennoscandian ice sheets. It is thus suggested that D–O events are a consequence of interactions of the windfield with the continental ice sheets and that better understanding of the wind field in the glacial periods is the highest priority. Wind fields are capable of great volatility and very rapid global-scale teleconnections, and they are efficient generators of oceanic circulation changes and (more speculatively) of multiple states relative to great ice sheets. Connection of D–O events to the possibility of modern abrupt climate change rests on a very weak chain of assumptions.

Abrupt climate change · Climate change · Climatology · Effects of global warming · Glacial period · Global warming · Ice core · Ice sheet · Ocean current · Teleconnection · Thermohaline circulation · Atmospheric and Environmental Gas Dynamics · Climate variability and models · Geology · Geology and Paleoclimatology Research · Oceanography · Paleontology