Rosenthal et al have put out quite a humdinger of a paper. They’ve reconstructed the temperature of the water flowing out of the Pacific to the Indian Ocean over the last 10,000 years and as deep as 900m.

The Indonesian Throughflow  is pretty significant in global ocean currents. There’s narrow routes for Pacific upper waters to squeeze through to the Indian Ocean through the Makassar and Lombok Straits, and via the Lifamatola Passage through the Banda Sea, and water comes in from both the North and South Pacific.


Points to note (assuming the study is right):

1.Temperatures started rising around 1700AD –  long before our carbon emissions.

2.That temperatures were much warmer (0.65C)  in 1100AD than they were in 1950.

3.8,000 years ago water was 1.5 to 2 degrees warmer — isn’t that meant to be a global catastrophe? Apparently coral reefs, fish, and turtles survived.

http://joannenova.com.au/

Observed increases in ocean heat content (OHC) and temperature are robust indicators of global warming during the past several decades. We used high-resolution proxy records from sediment cores to extend these observations in the Pacific 10,000 years beyond the instrumental record. We show that water masses linked to North Pacific and Antarctic intermediate waters were warmer by 2.1 ± 0.4°C and 1.5 ± 0.4°C, respectively, during the middle Holocene Thermal Maximum than over the past century. Both water masses were ~0.9°C warmer during the Medieval Warm period than during the Little Ice Age and ~0.65° warmer than in recent decades. Although documented changes in global surface temperatures during the Holocene and Common era are relatively small, the concomitant changes in OHC are large.

http://www.sciencemag.org/content/342/6158/617