[pabianice]

[TommyDale]

Yes, and the average temperature has gone up .1 degree during the past 100 years. At this rate, we will all be dead in 10,000 years. /sarcasm

[lepton]

Well, there's also a very vague and highly varying "definition" for surface temperature.

[Zon]

What does this mean for the Vostok ice core readings? Are they unreliable or has the methodology been set and therefore must maintain the same methodology when extrapolating into the future? Or am I missing something here?

[Lokibob]

Here is a show that was on BBC this week, debunking global warming.( called"The Great Global Warming Scandal" )
Warning: It is 75 mins long, so make time for it.
Excellent stuff, though:
http://www.youtube.com/watch?v=XttV2C6B8pU

[Diana in Wisconsin]

"Is there an average global temperature?"

I believe the answer is "42." ;)

[RightOnTheLeftCoast]

I used to teach TA in statistics as a grad student. The average is a horrible statistic. It is easily pulled by anomalous readings.

Example: What is the average of the following set: 1, 1, 1, 1, 10, 1?

The answer is easy enough to calculate: 2.5.

But is "2.5" representative of the set? What would be a typical value for the set? Is there any member of the set which is atypical and deserves another look?

Politicians love the average because it is such a fine tool for demagoguery. In the case of "average" temperature calculations, some readings come from peri-urban areas which have become increasingly developed in the past decades. Development means less foliage and brooks and more pavement. Significant increases in measured temperatures result, and these will pull any average calculated in a set which includes them.

[xcamel]

FReepmail me to get on or off

Click on POGW graphic for full GW rundown

Ping me if you find one I've missed.

---

[Dr. Frank fan]

I have made this point many times. What's the definition of "average"? Even if you settle on one definition, showing that this "average temperature" goes up might mean little. It may be that some other measure of "average temperature" goes down.

And even if you ignore this guy's point about nonequilibrium and just accept the most straightforward definition - what most people think of as "average" - even that is very problematic. The straightforward definition would say something like: take the temperature of every point on the earth, add 'em up, and divide by the number of points. (Rather: take the normalized surface-integral of the temperature function over the earth's surface.)

But how in the heck do you do that? It's not like we have a thermometer sitting on each square-inch, square-foot, or even square-mile of the earth. We simple don't know what the temperature is in most places. What about out in the middle of the ocean? (Do you have any idea how HUGE the Pacific Ocean is?) We have to rely on shipping routes, or infer the temperature from satellite data, which relies on a model, which may be wrong.

In reality, we only measure "the temperature" on some tiny tiny fraction of the globe, at a bunch of points. So in practice what people have to do is interpolate what the temperature is likely to be in between those points. And then take the "average" of that. But that interpolation process embodies a model in itself.

In other words, even gauging something as seemingly straightforward as the "average temperature" relies upon models. Even if it's today's "average temperature", to say nothing of the "average temperature in 1900 or 1400.

This is something that few people apprehend.

[Raycpa]

I asked this question years ago. It is almost impossible to get an average temperature of a single family home let alone an average for the earth.

[jongaltsr]

There is one standard that has been used since (I believe - 1932) and that is Bilge Water Recordings. Most countries started keep track of this temperature and is actually very accurate when combined with season, latitude and longitude.

[ChessExpert]

I have been wondering about term "average global temperature" also. Sometimes it seems that every discussion measures something different. Land measure, ocean temperature, atmospheric temperature have all been mentioned. I don't think they are all the same.

Nor are any of these homogeneous. Consider land temperatures in the United States. Go to
http://www.co2science.org/scripts/CO2ScienceB2C/data/ushcn/ushcn.jsp
and look at the recorded temperature in locations in your state. They may each tell a different story! One station may show a jaggedy line that trends up, while another may show a jaggedy line that trends down. How does one come up with a US trend? Or even a US average for one year. One could average the temperatures of all stations. But realize that if you add or subtract a station, your average changes. Do we have a set of stations that is properly distributed to compute a representative average? How about for the rest of the world?

Animals have a body temperature because they are alive. The earth may be marvelously suited for life and discovery, but it is not alive. It is hot one place and cold another. One place may warm, while another cools.

[ChessExpert]

I have been wondering about term "average global temperature" also. Sometimes it seems that every discussion measures something different. Land measure, ocean temperature, atmospheric temperature have all been mentioned. I don't think they are all the same.

Nor are any of these homogeneous. Consider land temperatures in the United States. Go to
http://www.co2science.org/scripts/CO2ScienceB2C/data/ushcn/ushcn.jsp
and look at the recorded temperature in locations in your state. They may each tell a different story! One station may show a jaggedy line that trends up, while another may show a jaggedy line that trends down. How does one come up with a US trend? Or even a US average for one year. One could average the temperatures of all stations. But realize that if you add or subtract a station, your average changes. Do we have a set of stations that is properly distributed to compute a representative average? How about for the rest of the world?

Animals have a body temperature because they are alive. The earth may be marvelously suited for life and discovery, but it is not alive. It is hot one place and cold another. One place may warm, while another cools.

[neverdem]

One Last Thing | Taking closer look at Al Gore's truth

Without Mouth-to-Mouth, CPR Still Works

Report: Toddler Contracts Rare Infection

Feeling the Pressure

FReepmail me if you want on or off my health and science ping list. Anyone can post any unposted link as they see fit.

[SunkenCiv]

Thanks ND.

Ross-Lempriere benchmark
http://www.john-daly.com/deadisle/index.htm

[ReleaseTheHounds]

A pertinent quote from Lord Kelvin: “To measure is to know. If you can not measure it, you can not improve it.”

[SunkenCiv]

This apropos quote was pointed out to me:

The urge to save humanity is almost always a false front for the urge to rule it. -- H. L. Mencken

[hosepipe]

[... Is there an average global temperature? ..]

Depends on WHERE you are...