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Comment Re:we were just heading back into an ice age. (Score 1) 187

No. Since the last interglacial 120000 years ago (the Eemian, warmer than the current) and the one we're living in (the Holocene) there has only been a glacial period (cold ... ).

My mistake. Thanks for correcting.

"Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history."

XKCD would have done well to include the error bars. They do illustrate this additional variability towards the right side between 16,000 and 15,500. If you include the error bars you can see that there is no contradiction. Even still, Marcotte was published in 2013. We're about 0.3C hotter now than the hottest observed temperature at that time: . That may very well exceed even the error bars and cover that last 25%.

Comment We're committed - but not to the extent she says (Score 2) 187

I took away from her study that, as far as she could extrapolate from the available data on climate/temperature cycles going back 2 million years, that we were pretty much smack at the point of the two curves one would expect during this point in time

Not quite. We reached the peak of the current interglacial about 8000 years ago. That peak is the result of Milankovitch cycles and the carbon, albedo, and other feedbacks - just as the peaks that came before. Temperatures have been falling slowly since then until the last 150 years when we increased atmospheric CO2 by about 70% by burning fossil fuels. Temperatures have risen along with the recent CO2 increase, just as you'd expect. The question she's trying to answer is, if we stopped releasing CO2 today, how much more warming would we observe just due to the CO2 we've already released. She uses the CO2 and temperature correlation over the previous glacial/interglacial periods to estimate the impact of CO2 on temperatures.

Gavin Schmidt shows why this is flawed and, given our current circumstances, likely to overestimate the impact. Here is a snippet: "In the previous post, I outlined how the combination of carbon cycle feedbacks to the Milankovitch forcing and the climate system response to CO2 gives rise to this correlation and that – by itself – it can’t be used to define the latter term. Furthermore, because the regression is being defined over ice age cycles where the biggest changes are related to the (now disappeared) North American and Fenno-Scandanavian ice sheets, the regression might well be much less for situations where only Greenland and West Antarctica are 'in play'."

Comment Re:we were just heading back into an ice age. (Score 5, Informative) 187

There have been several glacial/interglacial periods over the last 120,000 years. The peak of the current interglacial occurred about 8000 years ago. Since then temperatures have been slowly falling... up until about 150 years ago when something happened and temperatures dramatically reversed course.. Here's just the last 20,000 years by XKCD:

Comment Re:She's right (Score 3, Insightful) 187

I think the XKCD comic is rather more clever as he uses peer reviewed science. Your other perspective presumes that temperatures in Greenland represent temperatures around the world. That's not going to work. It looks like he snipped only certain parts though as using the whole core wouldn't fool "even the dimmest denier at WUWT" as Sue explains here:

Comment Re:So we're already committed (Score 3, Informative) 187

James Hanson, the previous director of NASA GISS and Gavin's former boss, weighs in with his own perspective. In a comment to the post he says in part: There are various technical issues with both Schmittner and Snyder approaches that lead them toward their low and high values. Suffice it to say that I expect the true answer lie between the two, but closer to Snyder’s. The evidence favors a temperature change in the range ~4-5C for LGM-Holocene, and thus a fast-feedback climate sensitivity close to 3C or a bit larger. This then leads to an ESS sensitivity ~6C or somewhat higher as discussed in our 2013 paper.

Comment Re:So we're already committed (Score 3, Informative) 187

According to Gavin Schmidt, the director of NASA Goddard Institute for Space Studies: "The paper claims that ESS is ~9C and that this implies that the long term committed warming from today’s CO2 levels is a further 3-7C. This is simply wrong." He goes on to show why:

Comment How contrarians reconcile incompatible views. (Score 1) 2

Opponents of a theory are not required to offer a coherent alternative to demonstrate errors and fallacies in the one proposed.

What they end up doing is offering several contradictory theories in an attempt to undermine the consilience of evidence. This is a result of attacking the theory piecemeal rather than addressing the cohesive theory. A contrarian will say "Not A because Y and not B because Z" even though Y and Z are incompatible. This study examines the mechanism that allows contrarians to hold these impossible views.

The paper gives numerous examples of high profile contrarians holding several incompatible views. There are even examples where these incompatible views are expressed within a single publication. I encourage you to take a look.

You may also want to look at consilience to understand why it is a flawed question to to ask for one particular piece of evidence in favor of a conclusion or to think that undermining that one piece of evidence by whatever means necessary does not undermine the theory. The section "In history" is particularly instructive.

Submission + - mechanics of the rejection of science ( 2

Layzej writes: Science strives for coherence. For example, the findings from climate science form a highly coherent body of knowledge that is supported by many independent lines of evidence. Those who reject climate science often rely on several mutually contradictory ideas. Hence, claims that the globe “is cooling” can coexist with claims that the “observed warming is natural” and that “the human influence does not matter because warming is good for us.” A recent study examines this behavior at the aggregate level, but gives many examples where contradictory ideas are held by the same individual, and sometimes are presented within a single publication.

The common denominator among contrarian positions is the conviction that climate change either does not exist or is not human caused, and that either way it does not present a risk (or if it does, then adaptation will deal with the problem). In a nutshell, the opposition to GHG emission cuts is the unifying and coherent position underlying all manifestations of climate science denial. Climate science denial is therefore perhaps best understood as a rational activity that replaces a coherent body of science with an incoherent and conspiracist body of pseudo-science for political reasons and with considerable political coherence and effectiveness.

Comment The Conspiracy Theory Detector (Score 1) 448

You're way in over your head and you don't even know it.


Looks like they're removing stuff now.

What, every single group that does temperature reconstructions is "removing stuff" and just happen to end up with the exact same answer? That's one hell of a conspiracy theory! It's item 4 on the conspiracy theory detector.

In my humble opinion, his successor is lying a lot more. That's why every month this year has been a "record."

So, nothing to do with the El Nino? That's item 10 on the conspiracy theory detector.

Even featured here on slashdot it's so suspicious,

That one's off the chart.

This site has actual photos of newspaper articles.

But isn't discussing global temperatures so is not really relevant to our discussion...

Those stubborn facts again-

Well, yeah :)

Yet another analysis:

Also not discussing global temperatures...

I understand you're not a scientist. However for God sakes, look at the data! Go into the distant past to present! Analyze it! Come up with a theory!

We've already got one, and as I've shown, the data fits quite well!

Another clue is they want to put people in jail that disagree with man made GW.

Yes. Clue #7

What's very frustrating to me is I've predicted this for 20 years that their models wouldn't hold up

Yes. That's got to be frustrating given how well they have!

Wonder why I haven't been responding? I

Because you're losing our bet so badly and because of how cocky and condescending you were when you entered it and because you're not particularly fond of the taste of crow?

Comment Re:GPS Pilot, right-wing wanker (Score 1) 448

we're really returning to where we were about 1000 years ago.

We've blown past where we were even 6000 years ago at the peak of the current inter-glacial. And FAST! It's all occurred since industrialization.

There is the fact that the 1930s was the hottest decade of the 20th century

Not even close.

Did you look at their last graph from 1880 on? That doesn't line up with the CO2 levels worth a damn.

The cyclical variations from PDO/ENSO/etc on top of the secular warming from CO2 explain each peak and valley in the temperature record quite well. It is naive to think that you would have a monotonic rise in temperatures that matched the monotonic rise in CO2. This is certainly not what the models show.

Here's a neat tool you can use to explore this. Set CO2 to 2.4 and PDO to 0.13 and you already have a pretty good match to the temperature record.

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