Thursday, November 03, 2011

Sort of annoying to see the Carbon Cultists and the realists constantly bickering over the statistical methods used in averaging and adjusting a figure called the Global Temperature.

Before you start arguing about the best way to form this Global Temperature, you have to ask whether it's valid to form a Global Temperature. Validity is not an assumption you can take as given; it's a hypothesis you need to prove first.

(Of course the Carbon Cult doesn't bother to ask any questions. They simply observe each instance of increase and declare with Prophetic Certainty; no evidence needed; that the increase is caused by Carbon. )

What struck me just now: Averaging temperatures at two locations to make a single temperature is a really basic statistical error that I learned about in junior high science class.

Remember this? The teacher turns on a cold faucet and a hot faucet; puts her right hand under the cold faucet and her left hand under the hot. Says "My right hand is at 40 degrees and my left hand is at 110 degrees. Therefore my average hand is at 75 degrees, which is Just Right!"

The more alert students get the point immediately and laugh.

= = = = =

The only valid thing you can do is to examine the trends of the various locations. If all trends run up and down together, then you can start asking questions about some influence that might affect all of them. And when you ask those questions, you'll find sunspots.

But that is NOT what we have on this particular planet in this particular century. What we have is unconnected trends. (You can use this useful NOAA graphing tool to examine those trends for yourself.) Some areas show a fairly steady upward trend over the century, some areas show a fairly steady downward trend. From this real situation you can't draw any conclusions about the whole globe. You can only say that different patterns are affecting different areas. Most of those patterns may be tied to sunspots, maybe some relate to soot, some are urban heat islands, some relate to ocean currents, etc, etc.

When you start with the assumption that there is an Average Global Temperature affected by some universal global influence, you're committing the sin of circular reasoning. The assumption is not automatic. It needs to be justified independently before you try to form a number that supposedly represents all changes on the globe at once. Any "conclusion" that follows from a circular start is prima facie invalid.

= = = = =

Sidenote: Even aside from this specific piece of illogic, the arithmetic mean is very rarely an appropriate way to form a typical value. For money (income, house values) the median is best. For numbers that relate to human perception (light intensity, sound intensity) a geometric average or RMS is best.

Labels: ,

Name:
Location: Spokane

Polistra was named after the original townsite of Manhattan (the one in Kansas). When I was growing up in Manhattan, I spent a lot of time exploring by foot, bike, and car. I discovered the ruins of an old mill along Wildcat Creek, and decided (inaccurately) that it was the remains of the original site of Polistra. Accurate or not, I've always liked the name, with its echoes of Poland (an under-appreciated friend of freedom) and stars. ==== The title icon is explained here. ==== Switchover: This 2007 entry marks a sharp change in worldview from neocon to pure populist. ===== The long illustrated story of Polistra's Dream is a time-travel fable, attempting to answer the dangerous revision of New Deal history propagated by Amity Shlaes. The Dream has 8 episodes, linked in a chain from the first. This entry explains the Shlaes connection.

My graphics products:

Free stuff at ShareCG

And some leftovers here.

ARCHIVES
March 2005 / April 2005 / May 2005 / June 2005 / July 2005 / August 2005 / September 2005 / October 2005 / November 2005 / December 2005 / January 2006 / February 2006 / March 2006 / April 2006 / May 2006 / June 2006 / July 2006 / August 2006 / September 2006 / October 2006 / November 2006 / December 2006 / January 2007 / February 2007 / March 2007 / April 2007 / May 2007 / June 2007 / July 2007 / August 2007 / September 2007 / October 2007 / November 2007 / December 2007 / January 2008 / February 2008 / March 2008 / April 2008 / May 2008 / June 2008 / July 2008 / August 2008 / September 2008 / October 2008 / November 2008 / December 2008 / January 2009 / February 2009 / March 2009 / April 2009 / May 2009 / June 2009 / July 2009 / August 2009 / September 2009 / October 2009 / November 2009 / December 2009 / January 2010 / February 2010 / March 2010 / April 2010 / May 2010 / June 2010 / July 2010 / August 2010 / September 2010 / October 2010 / November 2010 / December 2010 / January 2011 / February 2011 / March 2011 / April 2011 / May 2011 / June 2011 / July 2011 / August 2011 / September 2011 / October 2011 / November 2011 / December 2011 / January 2012 / February 2012 / March 2012 / April 2012 / May 2012 / June 2012 / July 2012 / August 2012 / September 2012 / October 2012 / November 2012 / December 2012 / January 2013 / February 2013 / March 2013 / April 2013 / May 2013 / June 2013 / July 2013 / August 2013 / September 2013 / October 2013 / November 2013 / December 2013 / January 2014 / February 2014 / March 2014 / April 2014 / May 2014 / June 2014 / July 2014 / August 2014 / September 2014 / October 2014 / November 2014 / December 2014 / January 2015 / February 2015 / March 2015 / April 2015 / May 2015 / June 2015 / July 2015 / August 2015 / September 2015 / October 2015 / November 2015 / December 2015 / January 2016 / February 2016 / March 2016 / April 2016 / May 2016 / June 2016 / July 2016 / August 2016 / September 2016 / October 2016 / November 2016 / December 2016 / January 2017 / February 2017 / March 2017 / April 2017 / May 2017 / June 2017 / July 2017 / August 2017 / September 2017 / October 2017 / November 2017 / December 2017 / January 2018 / February 2018 / March 2018 / April 2018 / May 2018 / June 2018 / July 2018 / August 2018 / September 2018 / October 2018 / November 2018 / December 2018 / January 2019 / February 2019 / March 2019 / April 2019 / May 2019 / June 2019 / July 2019 / August 2019 / September 2019 / October 2019 / November 2019 / December 2019 / January 2020 / February 2020 /

Major tags or subjects:

Carbon Cult
Carver
Constants and variables
Defensible spaces
Experiential education
From rights to duties
Grand Blueprint