2011-01-11 09:14:43Crux of a Core... Round 2
Rob Honeycutt



Okay gang.  Let's try this again...

Here is a rewrite of the article I tried to write many weeks ago.  Check it out and let me know what you think.



Added to this, I have a commitment from Peter Sinclair (Climate Denier Crock of the Week) to do a tandem project here.  If you guys like this article  then Peter will create a video that goes along with it and we'll post them at the same time.  As well, Peter has a gig going with Climate Progress where a day after Peter's video's post they do a short blog post on it there.  Kind of the same with SkS.  Joe Romm posts a bunch of SkS articles on his site.  This one will be a triple whammy.


2011-01-11 10:38:19



Can you get to the point sooner? I think a lot of readers would quit 1/3 of the way in.


2011-01-11 10:50:46
Daniel Bailey
Daniel Bailey

Nice job.  Thorough, well-written.  Maybe a link to an Alley video pointing to the bald spot in question: http://www.youtube.com/watch?v=-NQPolcYoIc.

Luv the Churchill quote at the end; one of my favs...





2011-01-11 10:57:42
Rob Honeycutt



Updated the opening paragraph.  See if that reads better.

2011-01-11 10:59:46
Rob Honeycutt



Thanks Daniel.  Will plug that in. 

2011-01-25 09:42:39Easterbrook running with this theme now
John Cook


I got this email this morning:

Could you comment on this article.

I replied with:

Two things come to mind when I read this article. Firstly, he's talking about temperatures at a single location in Greenland. Temperatures are always going to fluctuate more dramatically at a single location. Weather is heat shifting around - so individual locations will show big changes while the total amount of heat remains the same. So globally, temperature does not shift as much - the global temperature depends on how much heat the planet is gaining or losing (eg - the planet's energy imbalance).

So this whole argument uses the most common of climate skeptic tactics - cherry picking a single piece of data while neglecting the full picture.

However, that's not to say climate hasn't changed in the past - global temperature has changed dramatically in the past (Easterbrook is just over-interpreting the Greenland data). And on that point, there is a more fundamental flaw throughout the article's whole line of thinking.
Easterbrook argues that dramatic climate change in the past means there is nothing to worry about now. But in fact, what past climate change tells us is our climate is sensitive. In other words, when the planet warms for whatever reason, positive feedbacks amplify the warming.

Those same positive feedbacks are now amplifying the warming caused by rising CO2 levels. Just over the last few weeks, observations have come in finding the positive feedback from melting snow and ice is more than twice as great as what climate models were predicting (http://www.skepticalscience.com/Flanner2011.html). This is the lesson to be learnt from past climate change - and is well documented in the peer-reviewed literature. I can understand a blogger misunderstanding past climate change but how a scientist like Easterbrook can get it so wrong is completely beyond my understanding.

The Greenland core argument has gotten widespread enough, it deserves its own skeptic argument which I will probably add when Rob's blog post goes live.

2011-01-25 09:57:50Yay!
Rob Honeycutt



That's good!  I'll circle up with Peter Sinclair and see if we can wrangle a video out of him at the same time.


2011-01-25 09:58:57
Rob Honeycutt



Maybe there's a "Crux of a Core part 3 - Easterbrook."   :-)


2011-01-27 10:17:39
Andy S



I would be careful about this statement

1) GISP2 is clearly a local record of temperature for the summit of the Greenland ice sheet, not a proxy for global temperature.

I don't think it is strictly "local" but rather regional. My understanding is that the oxygen isotope ratio in rain or snow is largely influenced by where the water originally evaporated. But it's more complicated than considering it as just as the temperature at the nearest ocean upwind unfortunately. Repeated condensation/precipitation cycles can also concentrate the effect (imagine a chain of lakes that evaporate and then rain into the next one).  I also read somewhere that the isotopes can also be affected by conditions at the precipitation site, temperatures and the amount  sublimation of snow after it settles. What this boils down to is that the oxygen isotopes provide a rather fuzzy provenance for the proxy measurement, not only that but the provenance area could change through time for a specific core site as the climate changes. 

But I'm no expert and it's not easy to find accessible material on this. I think this would be a great topic for a guest post. Maybe John could persuade Alley to do something for us?