caerbannog

The following snippet has been lifted from one of the papers that scientists complained about in those leaked emails (link: http://climatedebatedaily.com/southern_oscillation...

"To remove the noise, the absolute values were

replaced with derivative values based on variations."

You can use your pdf reader's search feature to view this in its full context, if you wish.

Now, my question is: Is this application of the derivative operation really a good way to reduce noise, and is it appropriate for use on data where you wish to determine the presence or absence of a long-term trend?

Once again, I'd to give the skeptics here the first crack at this.

Dana1981, pegminer, linlyons, et al., feel free to jump in after the skeptics have given it a go. ;)

After reading http://www.realclimate.org/index.php/archives/2009... it would be hard to imagine otherwise.

In particular, someone who repeated the Superfreakonomics authors' claims about the impacts of solar-panel albedo in a high-school science class might well find himself repeating the class in a summer-school makeup session.

Note: Dr. Raymond Pierrehumbert, the author of the article I linked to above, is a geophysics professor at the University of Chicago and is one of the world's leading climate-science experts.

Note to those who think that the above article is wrong -- If you respond with an answer here, please provide detailed explanations of where Dr. Pierrehumbert went wrong (mistakes in his math, etc).

No tinfoil-hat conspiracy-mongering please.

Also, I already know that Al Gore is fat and his momma dresses him funny. So let's leave Gore out of this.

None of the responders to my previous question here (http://answers.yahoo.com/question/index?qid=200910... realized that my question was a parody. IMO, that's not the fault of those who responded.

Instead, could it be evidence that Poe's Law applies to the AGW "skeptic" community?

Poe's Law states that it is difficult to construct a parody of a fundamentalist/kook argument that is easily distinguishable from the genuine article.

See http://www.aaas.org/news/releases/2009/media/1021c... for more.

Specifically, does eigenvalue size really matter?

If you look at the eigenvalues computed from Mann's hockey-stick data, you'll see that the leading eigenvalue (associated with the hockey-stick PC) is about 0.4. (Google is your friend here.) The remaining eigenvalues rapidly decay to zero; only two or three other eigenvalues are more than a tiny fraction of the size of the first eigenvalue.

Now if you look at the eigenvalues of random noise data that has been "mined" for a hockey-stick, you will see that the leading eigenvalue is on the order of 0.05. The remaining eigenvalues decay away slowly enough so that you have 30 or 40 eigenvalues that are a significant fraction of the size of the first eigenvalue.

What does that tell you about the differences between Mann's data and random noise data?

In a post of his over at WUWT, Anthony Watts attempted to interpret temperature histograms generated from GISS, HadCRUT, UAH, and RSS data-sets. Here is a link to that post: http://wattsupwiththat.com/2008/02/28/a-look-at-4-... (you'll need to scroll down to the histogram discussion).

But Watts really "stepped in it" in his attempt to interpret the temperature histograms. Can anyone here explain to us what Watts' biggest blunder was?

As before, I'd like to reserve the first day for responses from "skeptics".

It would appear to be so according to its latest official position statement on global warming. Below are some excerpts (taken from http://www.geosociety.org/positions/pos10_climateC...

Global climate has warmed by ~0.7 °C since the middle to late 1800s, and human activities (mainly greenhouse-gas emissions) account for most of the warming since the middle 1900s. If current trends continue, the projected increase in global temperature by the end of the twenty-first century will result in large negative impacts on humans and other life forms. Addressing the challenges posed by future anthropogenic warming will require a combination of national and international emissions reductions and adaptations to those changes that occur.

GSA members are encouraged to take an active part in outreach activities to educate the public at all levels (local, regional, and national) about the science of global warming and the importance of geological research in framing policy development. Such activities can include organizing and participating in community school activities; leading discussion groups in churches or other civic organizations; meeting with local and state community leaders and congressional staffs; participating in GSA’s Congressional Visits Day; writing opinion pieces and letters to the editor for local and regional newspapers; contributing to online forums; and volunteering for organizations that support efforts to effectively mitigate and adapt to global climate change.

GSA members are encouraged to discuss with businesses and policymakers the science of global warming, as well as the opportunities for transitioning from our predominant dependence on fossil fuels to greater use of low-carbon energies and energy efficiencies.

GSA should actively engage and collaborate with other earth-science organizations in recommending and formulating national and international strategies to address impending impacts of anthropogenic climate change.

(from http://www.opinionjournal.com/extra/?id=110008220)

"Alarmists have drawn some support for increased claims of tropical storminess from a casual claim by Sir John Houghton of the U.N.'s Intergovernmental Panel on Climate Change (IPCC) that a warmer world would have more evaporation, with latent heat providing more energy for disturbances. The problem with this is that the ability of evaporation to drive tropical storms relies not only on temperature but humidity as well, and calls for drier, less humid air. Claims for starkly higher temperatures are based upon there being more humidity, not less--hardly a case for more storminess with global warming."

There's quite a whopper of an error in the above statement, an error that should be obvious to anyone with a basic understanding of Earth/physical science. Can anyone here spot the problem and explain what it is?

I'm going to ask "Dana1981", "Paul", and "Dawei" to hold off here -- I'm sure that they know the answer and I don't want them to spill the beans too soon. ;) ;)