Medieval Warm Period Undeniable, Pronounced in Antarctica and Poland | Hacker News Reader

Medieval Warm Period Undeniable, Pronounced in Antarctica and Poland

wattsupwiththat.com

3 pointsdadjoker6 comments

The headline-ese will be seized on as an anti-AGW "aha" moment but really? this is science doing scienting. The models can't explain the period because it's not a CO2 driven event. So, the models need adapting and the current contribution understood. Does this invalidate AGW? Nope. Nor does this ocean current on it's own slam dunk the reasons why the warm period happened. It's a theory backed by indirect evidence from animal population studies.

Just musing on ways to repackage the logic-scenario there...

"You keep telling me that the car will break because I've gone 20k miles without changing the engine-oil and filter. But guess what!? An expert told me that weird noises and smells can happen for other reasons! Therefore your reason must be wrong, and you're trying to trick me into wasting my money."

I think thats a rather distorted take. This research shows the medieval warming period may have root causes in ocean currents and shows population studies of sea life to back it up.

The current models for climate focus on CO2 and cannot explain the medieval warming period.

The argument I throw is that this may be true, but it does not invalidate AGW, it only says there are other sources of warming, than CO2. It does not mean all warmings are because of Ocean current movements, or are unrelated to CO2 or anthropogenic pressures. It does not invalidate climate models which cannot explain the medieval warm period, it simply shows another potential source of warming at that time. Of course the question of why the currents shifted has to be asked. And in like sense, the question about the strength of current day ocean currents has to be asked. But there is no necessary nexus for why they changed then, and why they change now. On the other hand, the component of change over time which does track rise in global CO2 and other effects is large. I believe as others do, compellingly large.

I don't see how that fits your Analogy.

It's not an analogy of the research itself, it's an analogy of how someone might fallaciously use the research to declare that CO2-based warming is not happening.

Sure, it's possible the symptoms are due to some other unclear cause, but it's sufficiently unlikely that the person is being unreasonable.

I think the reductive view is "because the medieval warm period was caused by ocean currents all warming COULD be caused by ocean currents and since ocean currents aren't what the model says (about modern warming) the model must be wrong therefore AGW is wrong because it can't encompass this warming event"

Obviously this is not a view I espouse.

For additional context;

Watts Up With That (aka WUWT) is a long standing anti-AGW, human climate change skeptic site.

Which is fine, all the points raised there are worth looking into and are addessed elsewhere. That said WUWT is going to overstate the importance of any percieved cracks in the AGW argument and will misrepresent various things.

In this case, straight out of the gate:

  Medieval Warm Period Undeniable, [..]  the troublesome Medieval Warm Period, which has long been a thorn for climate alarmists [..] That’s why people would rather keep the Medieval Warm Period quiet.

That's a lot of emotive loading and passive aggressive accusation.

My background is large scale geophysical exploration for minerals and energy - country scale surveys, large area resource maps, etc. FWiW the majority of people involved in global scale geophysics working for industry have little to no issue with AGW .. it's fairly straightforward.

* Very few (none that I know) in the geophysical, climatic, etc. game deny the existence of the Medieval Warm Period - to imply that some "keep it quiet" or deny it is weasel phrasing.

* Climate alarmists.

You swing a ball on a long cable, it precesses. You heat up one end of a bar of steel, the heat flows. You put more blankets on the bed, your feet heat up. You put more insulation in the air, more energy is trapped.

That's AGW climate change - the implications should cause some alarm, it's more important to act.

So that's the WUWT framing on the MWP .. it's apparently contrary to AGW and can disprove it (it doesn't) and every paper tangential to MWP is cast to be stronger than it is and to be a secret source that breaks AGW.

Out in the mainstream climate scientists have no issue looking a the MWP, it's not CO2 based, it's generally thought to be quite localised to parts of Europe and elswhere and less of a global change in global mean surface energy than a specific kind of rebalancing (perhaps related to ocean currents).

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