Climate Dynamics

, Volume 16, Issue 4, pp 241–255

CLIMAP SSTs re-revisited

  • T. J. Crowley

DOI: 10.1007/s003820050325

Cite this article as:
Crowley, T. Climate Dynamics (2000) 16: 241. doi:10.1007/s003820050325


Since the 1976 publication of the CLIMAP ice age sea surface temperature (SST) reconstruction showing a 1–2 C tropical cooling a substantial debate has arisen as to whether tropical SSTs may instead have been 4–5 colder than present. Herein I review the arguments for large SST variations and question a number of key findings, particularly the validity of ice-age coral SST estimates and “down-projecting” tropical snowline changes to the surface. GCM results indicate that an intermediate solution requiring ∼2.5 C warm pool cooling is consistent with most quantitative low elevation surface land data and is small enough to allow the persistence of tropical biota in the ocean during glacial times. The proposal reduces estimated ice-age climate sensitivity (for a doubling of CO2) from a “high-end” sensitivity of about 4.5 C (for a 5–6 C tropical cooling) to a “mid-range” sensitivity of about 3.0 C for a 2.5 C warm-pool decrease.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • T. J. Crowley
    • 1
  1. 1.Texas A&M University, Department of Oceanography, College Station, Texas 77843-3146, USA E-mail: tcrowley@ocean.tamu.eduUS

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