Thus, we take 4.5 °C as our best estimate for LGM cooling, implying an amplification of surface temperature change by a factor of two relative to deep ocean temperature change for this climate interval. (rsta.royalsocietypublishing.org)
«deep ocean temperature change does not provide a good indication of surface temperature change when the deep ocean approaches the freezing point, as quantified by Waelbroeck et al. (2002). (skepticalscience.com)
In fact, Bova et al. (2016) conclude that deep ocean temperature changes for the last 200 years are apparently so negligible they are «below the detection limits». (notrickszone.com)