Conspiracies, volcanoes, and two thousand years of ocean cooling and warming

Deniers at WUWT are (belatedly) trying to shoot down a paper published in Nature GeoScience last month. It's from authors who are part of the Ocean2k project, the ocean component of the PAGES 2K international consortium. The lead author is Helen McGregor from the University of Wollongong in Australia.

Anthony Watts was first to protest (archived here). In a bout of denial at WUWT, he claimed that just because there were a lot of volcanic eruptions on earth from somewhere around 1200 AD to 1800 AD, it doesn't mean they caused the observed cooling. He wrote a headline: "The new poster child for ‘correlation is not causation’: industrial revolution ended 1800 years of volcanic induced cooling".

In that one headline he rejected both greenhouse and volcanic forcing. Naturally, he didn't say what he thinks caused the earth to cool over time, or what is causing the current warming. More of the WUWT magic?