Past sea surface temperatures as measured by different proxies—A cautionary tale from the late Pliocene

The paleoclimate community uses a variety of different proxies to reconstruct past sea surface temperatures. Estimates from different paleothermometers are often used interchangeably despite a scarcity of studies exploring the validity of this practice. Here, we provide an orbital resolution case study from the Pliocene using Mg/Ca and alkenone paleothermometry that reinforces results from previous studies showing consistent estimates for some climate parameters and inconsistent results for others. We argue that the paleoclimate community should undertake an effort to more systematically evaluate if, when, and where climate estimates from different paleothermometers can be used interchangeably.