It didn’t take long for my last post to draw a reply from Ian Wishart, and — no surprises — it’s another lengthy diatribe. Unfortunately for Ian, it is also a very public own goal –demonstrating very nicely one of my central contentions: he doesn’t understand the stuff he’s writing about. Here’s the relevant passage (sorry about the lengthy quote, but it takes him a while to get his shot lined up):
…Gareth helpfully directs to a NASA feature on ocean cooling. There’s nothing in it that contradicts my usage of Willis in the book, but what it does say backs up one of my other assertions that Gareth had a problem with in our “anonymous” discussion thread on Tumeke previously about the impact of undersea volcanoes on ocean heat and GHG emissions.
When I pointed out scientists have recently discovered a massive volcanic field under the Arctic that began erupting in a catastrophic, albeit submarine, sense in 1999, Gareth, posting as “Response to Ian”, stated:
“If you are implying that they are influencing Arctic sea ice you are absolutely out in la-la land. The amount of heat released is miniscule compared to the heat capacity of the cold Arctic ocean.”
So if a large volcanic field under a relatively small area of ocean has no impact on warming the water, why does the NASA study on ocean cooling Gareth pointed us to say this:
“They are also exploring how volcanic eruptions influence ocean heating, and whether a better understanding of how volcanoes influence the energy balance of the ocean will help explain short term variability in ocean warming and cooling”
The NASA feature then quoted the CSIRO research team directly:
“One thing we found was that climate models that do not include volcanic forcing tend to overestimate the long term change, and their simulated decadal variability is not in agreement with the observationsâ€¦this kind of result tells us volcanic forcing is important, but that we don’t totally understand it yet”.
Another example, then, of Trufflehunter shooting from the lip because he isn’t across the latest scientific research. 95% of the world’s active volcanic vents are underwater. I quoted other scientists in the book who thought volcanic and tectonic activity might well be significant in regard to sea levels and thermal expansion, but Gareth’s response was:
“One possibility that Wishart fails to consider is that tectonics and volcanoes weren’t ignored and their effects are trivial.”
Well, Gareth, go back and read the report you referred us to. Apparently other scientists don’t think they’re trivial at all.
And the ball’s in the back of his own net! It’s a mistake that only someone who had no real grasp of the subject could make, and Wishart makes it in a typically aggressive manner. The CSIRO team are (of course) talking about the cooling effects of large, Pinatubo-style volcanic eruptions (you know, the ones that occur above the surface of the sea) as a brief check of their paper would have told him…
Church et al. (2005) show that large volcanic eruptions cool [my emphasis] the global ocean and produce a drop in global sea levels. While this volcanic signal is clear in appropriately forced models and the global tide-gauge record, it is not as clear in the global thermosteric sea level record (the component of sea level change due to the thermal expansion of the ocean and closely related to ocean heat content), and there are several instances where global sea level is rising but steric sea level is falling…
[Update 7/5: Wishart concedes and admits to "winging it", but then proceeds to enlarge the deep hole he's already dug for himself. Any readers care to explain for his benefit precisely why undersea volcanism has a trivial impact on oceanic heat budgets? The rest of his post is just wibble.]