Very true. Of course, the question is how accurately can we measure it? That’s not an easy question to answer, even now.

“So is it hotter in June than it is in January? We don’t need a 100% accurate temperature record to answer that question.”

Are you talking about local or global temperature? In some places, January is hotter, in others, June, in yet others, they’re about the same. Exceptional weather can give very cold June days cooler than some very warm January days in many places.

Considering global temperature, the different values are far enough apart to be able to say June is warmer than January. But it’s not a trivial determination or made by a single thermometer. And of course being able to distinguish summer from winter does not imply you can detect a fraction of a degree of global warming, which is obviously the context in which it was meant.

“We just need a thermometer that is accurate enough to measure the difference.”

Not for global temperature. What you need is a lot of thermometers (or a few moving very fast), to have them in the right places, and to have an understanding of how the temperatures between them are related.

The global mean temperature anomaly is not simply a thermometer reading. First you have to find the mean temperature over a day by measuring the maximum and minimum temperature, adding and dividing by two. (This is a specialised and superior meaning of the word “mean” known only to climate scientists, that annoys those poor ignorant mathematicians no end.) The thermometer has to be placed 1.5-2 metres above the ground, because the temperature varies rapidly with height near the surface. The rate at which it does so varies with location, wind speed, time of day, and other factors. It varies with shade, local vegetation, nearby structures, artificial heat sources, colour of ground, aging of thermometer housing, etc. all of which vary over very short ranges. And it depends on the type of thermometer. Older glass and mercury thermometers were read to the nearest degree. (As you average more and more measurements all rounded to the nearest degree, how does the accuracy of the result change?) Newer electronic ones are not much better, and have different errors. The change from one method to another can introduce systematic biases in the result. You need to keep the number of thermometers and their locations constant, or net biases will change where/when the thermometers are added or dropped.

And since most of the world is covered by oceans, you need a different definition, and different sensors to be able to measure it – which likewise have their own biases and issues.

So no, you don’t “just need a thermometer”.

“My understanding is that the world has only had accurate temperature taking/keeping/tracking capability for right at 100 years.”

Locally, there are thermometer-based temperature records going back to 1659. (HadCET.) Globally, it is arguable that we didn’t have significant records over most of the oceans until the 1940s, and we didn’t have genuinely global records until the late 1970s with the advent of satellite measurement. And of course satellites measure the temperature over a range of altitudes, not specifically 1.5-2 m above the surface.

“Your understanding is wrong and apparently based on the idea that the only thermometers that exist are man-made.”

Ah, yes! The proxies!

Problem is, even at the best of times they’re not very accurate thermometers, and quite often not acting as thermometers at all. Really, you need to check first and prove that the proxy is a reliable thermometer. This step is usually skimped, though. Some people blindly assume that if a record is correlated with the global temperature record, then that’s what it’s measuring. If some (apparently otherwise identical) examples are not correlated, then they’re quietly ignored. Some even assume that if it’s correlated over part of the record but not over the rest, then the bit where it doesn’t fit is some sort of anthropogenic error and should be deleted and replaced with a different data source, but the original source assumed to be still valid prior to the instrumental record. (You need to pick cherries to make cherry pie!)

If your “thermometer” shows the temperature going down when the temperature is actually going up, can you still call it a thermometer? Shouldn’t you question whether it is really temperature that it is measuring? It’s a question other scientists should be able to form an opinion on.

how many of them do all of you scientists have 100% accurate temperature readings, every where in the world on a 24-X-7-X-365 basis?

I wonder what you think the definition of a “pragmatic realist” is.

We don’t have 100% accurate temperature readings, now. So is it hotter in June than it is in January? We don’t need a 100% accurate temperature record to answer that question. We just need a thermometer that is accurate enough to measure the difference.

My understanding is that the world has only had accurate temperature taking/keeping/tracking capability for right at 100 years.

Your understanding is wrong and apparently based on the idea that the only thermometers that exist are man-made.

The 20th century climate was chosen as “normal” because it was what most of our current techno-globalized civilization was built around. Without those climatic conditions, what we take for granted as modern human life likely wouldn’t exist. The whole reason people worry about this problem is because of its human-scaled potential for damage. Throughout most of Earth’s history it was either much hotter or much colder than it is now, but since usually no people were around to suffer and die in the attendant changes, it is quite irrelevant to this issue.

@Justin Schuck: I don’t see you making an argument. Tyrannosaurus rex has been known to science for only about 100 years, and only a small handful of specimens have ever been discovered, none of them perfectly complete. Is it ridiculous to say that Tyrannosaurus rex existed?

I grant that this is not a perfect analogy, as I really shouldn’t insult global warming by comparing it to something as relatively inconsistently and spottily demonstrated as the existence of Tyrannosaurus rex.

Look, I’m not a scientist, but I know that if any graph, scale, etc is to be accurate & more important…have integrity you must, repeat MUST have a full, relative scale of data.

To my point… My understanding is that the world has only had accurate temperature taking/keeping/tracking capability for right at 100 years. So, if all you have is 100 years to go off of, it’s ridiculous to insist Global Warming does exist. It’s also ridiculous to say that it doesn’t exist. The tangents that both sides go to in order to try & correlate the most wild, left field tangents to prove this point, that point or disprove this point, that point are so damned silly. At the end of the day folks, there’s just not enough evidence to state whether Global Warming is a big hoax or if we’re frying like eggs in a pan. You just don’t have the data necessary to quantify an accurate answer either way.

I’m sorry, but this reads like the argument from Nigel Tufnel of Spinal Tap pointing out that his amplifier goes up to eleven.

Marty DiBergi: Does that mean it’s louder? Is it any louder?

Nigel Tufnel: Well, it’s one louder, isn’t it? It’s not ten. You see, most blokes, you know, will be playing at ten. You’re on ten here, all the way up, all the way up, all the way up, you’re on ten on your guitar. Where can you go from there? Where?

Meteorologists and science communicators should be a little bit brighter than that.

Waiting 23 years to update the average leads to a false sense of “extreme” temperature change. It doesn’t matter if you update the average 23 years from now or every year for 23 years, the temperature change will be the same. In science I’ve noticed that while writing papers it’s always better to present the facts exactly as they are and not worry about whether or not someone views the data as “extreme.” The numbers don’t lie, and I have faith that the public will come around to understanding the climate issue we are faced with today. Playing with when to release numbers walks the line of committing numerical fraud like the climate deniers commonly do.

I don’t see the problem. Changing the method of calculating “normal temperature” will not stop the temperature trend from rising.

It’s true that the public may lose track of this as they go about their daily lives. But the data will still be there to remind them.

I don’t see anyone but you making that claim here.

The hottest temperature ever recorded for Nebraska was 118°F at Minden on 7/24/1936. That same year saw a record-breaking stretch of 29 days with temperatures below 0°F in the state.

That’s according to Wikipedia and to this site: http://coolweather.net/statetemperature/nebraska_temperature.htm

Then there’s this:

“The highest temperature recorded in Nebraska is 118°, Fahrenheit. This record high was recorded July 15, 1934 at Geneva; on July 17, 1936 at Hartington; and on July 24, 1936 at Minden. The lowest temperature in Nebraska, -47°, was recorded on February 12, 1899 at Camp Clarke and on December 22, 1989 at Oshkosh.”

Source: http://www.netstate.com/states/geography/ne_geography.htm

All very interesting but, as you say, not supportive of a trend. For that, you have to look at collections of data. And lately we’re assembling quite a collection.