Thursday, April 5, 2012

Starting line on CO2-driven deglaciation

Background:  for a long time, it has been held as a basic arguing point by the climate skeptic crowd that there's an ice core record from Antarctica that shows global temperatures rising about 800 years before Earth's temperature started rising when the Earth's climate transition from glacial to interglacial conditions during the Pleistocene Era.  This is the so-called "lag" problem. 

Numerous informed blog posts have addressed this:

The lag between temperature and CO2 (Gore's got it right).

CO2 lags temperature - what does it mean?


Now, here's some of the better summaries of the most recent Nature paper, first-authored by Jeremy Shakun.  Put simply, combining a global (emphasis on the global) temperature proxy record plus a state-of-the-art climate model clarified the timing of events on a regional basis.  That's what has been lacking before.  And that's why anyone who clings to the "800 year lag" argument and is dismissive toward the continuing process of knowledge advancement via the scientific process is demonstrating CLASSIC confirmation bias.

1. Carbon dioxide caused Ice Age's end, pioneering simulation shows

2. How carbon dioxide melted the world

3. Greenhouse gas is no weakling

Here's the basic summary, from the second link:

"The global record shows that the end of the ice age was probably triggered by changes in Earth’s orbit and subsequent shifts in the ocean currents that move heat around the world. But rising CO2 levels amplified this initially regional warming.

It's not clear what caused the rise in carbon dioxide. One idea is that it leached out of the deep ocean when melting ice and shifting winds brought water rich in the gas up to the surface.

In Antarctica, the temperature rose more quickly than elsewhere owing to a slowing of the ocean currents that usually carry heat away from the south to the north. This accounts for the lag between the carbon dioxide and temperature records on that continent."

Regarding the recent paper, the uninformed masses at WattsUpWithThat are all over it.  And probably all wrong about it.  But I include this because it shows how the skeptical mind deals with contravening evidence by belittling and dismissing it without valid grounds to do so, based primarily on biased thinking.

http://wattsupwiththat.com/2012/04/04/a-new-paper-in-nature-suggests-co2-leads-temperature-but-has-some-serious-problems/

It should be noted that it only has serious non-peer-reviewed problems stated by people who have a mindset already attuned to only that evidence which confirms their viewpoint.

I hope to write a longer analysis of this later.  But this is a good start for now. 



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