Another indication of MWP and LIA being global

From CO2 Science, another peer reviewed paper with a paleoclimatology reconstruction based on cores containing plankton shells, show that both the Medieval Warm Period (MWP) and the Little Ice Age (LIA) can be seen in Indonesia. In the past, critics have said these events to be “regional” implying they occurred only around Europe, due to lack of historical records in other regions of the world.

Since the Oxygen18 isotope dating method seems well proven, it would seem this study has a good basis for its claims. Even RC’s Gavin Schmidt likes it.

Co2 Science writes:

From the authors’ Figure 2b, adapted below, we calculate that the Medieval Warm Period was about 0.4°C warmer than the Current Warm Period.

The Makassar Strait (Wikipedia)

Foraminifera samples.

Description

Oppo et al. derived a continuous sea surface temperature (SST) reconstruction from the Indo-Pacific Warm Pool (IPWP), which they describe as “the largest reservoir of warm surface water on the earth and the main source of heat for the global atmosphere.” This history — which was based on δ¹⁸O and Mg/Ca data obtained from samples of the planktonic foraminifera Globigerinoides ruber found in two gravity cores, a nearby multi-core (all at 3°53’S, 119°27’E), and a piston core (at 5°12’S, 117°29’E) that were recovered from the Makassar Strait on the Sulawesi margin — spans the past two millennia and, as they describe it, “overlaps the instrumental record, enabling both a direct comparison of proxy data to the instrumental record and an evaluation of past changes in the context of twentieth century trends.” Reconstructed SSTs were, in their words, “warmest from AD 1000 to AD 1250 and during short periods of first millennium.”

Reference

Oppo, D.W., Rosenthal, Y. and Linsley, B.K. 2009. 2,000-year-long temperature and hydrology reconstructions from the Indo-Pacific warm pool. Nature 460: 1113-1116.