Guest Post by Willis Eschenbach
I got to thinking about how the information about temperatures is presented. Usually, we are shown a graph something like Fig. 1, which shows the change in the US temperatures over the last century.
Figure 1. Change in the US annual temperatures, 1895-2009. Data from the US Historical Climate Network (USHCN DATA) [Yes, it’s in Fahrenheit, not Celsius, but hey, it’s US temperature, and besides I’m doing it in solidarity with our valiant allies, all the other noble countries that are bravely fighting a desperate rear-guard action against the global metric conspiracy … Liberia and Myanmar …]
Whoa, this is obviously a huge and scary change, look at the slope of that trend line, this must be something that calls for immediate action. So, what’s not to like about this graph?
What’s wrong with it is that there is nothing in the graph that we can compare to our normal existence. Usually, we don’t even go so far as to think “Well, it’s changed about one degree Fahrenheit, call it half a degree C, that’s not even enough to feel the difference.”
So I decided to look for a way to present exactly the same information so that it would make more sense, a way that we can compare to our actual experience. Fig. 2 is one way to do that. It shows the US temperature, month by month, for each year since 1895.
Figure 2. US yearly temperatures by month, 1895-2009. Each line represents the record for a different year. Red line is the temperature in 2009. Data source as in Fig. 1. Photo is Vernal Falls, Yosemite
Presented in this fashion, we are reminded that the annual variation in temperature is much, much larger than the ~ 1°F change in US temperatures over the last century. The most recent year, 2009, is … well … about average. Have we seen any terrible results from the temperature differences between even the coolest and warmest years, differences which (of course) are much larger than the average change over the last century? If so, I don’t recall those calamities, and I remember nearly half of those years …
To investigate further, Fig. 3 looks at the decadal average changes in the same way.
Figure 3. US decadal average temperatures by month, 1900-2009. Red line is the average for the decade 2000-2009. Photo is Half Dome, Yosemite.
Most months of the year there is so little change in the decadal averages that the lines cannot be distinguished. The warming, what there is, occurred mostly in the months of November, December, January, and February. Slightly warmer temperatures in the winter … somehow, that doesn’t strike me as anything worth breathing hard about.
My point in all of this is that the temperature changes that we are discussing (a global rise of a bit more than half a degree C in the last century) are trivially small. A half degree change cannot be sensed by the human body. In addition, the changes are generally occurring in the winter, outside of the tropics in the cooler parts of the planet, and at night. Perhaps you see this small warming, as has often been claimed, as a huge problem that “vastly eclipses that of terrorism” (the Guardian). Maybe you think this is a pressing concern which is the “defining issue of our era” (UN Secretary Ban Ki-Moon).
I don’t. I’m sorry, but for me, poverty and injustice and racial prejudice and totalitarian regimes and recurring warfare and a lack of clean drinking water and torture and rampant disease and lack of education and child prostitution and a host of other problems “vastly eclipse” the possibility of a degree or two of warming happening at night in the winter in the extra-tropics fifty years from now.
Finally, the USHCN records are not adjusted for the urban heat island (UHI) effect. UHI is the warming of the recording thermometers that occurs as the area around the temperature recording station is developed. Increasing buildings, roads, pavement, and the cutting down of trees all tend to increase recorded temperatures. Various authors (e.g. McKitrick, Spencer, Jones) have shown that UHI likely explains something on the order of half of the recorded temperature rise. So even the small temperature rise shown above is probably shown somewhere about twice as large as it actually is …
My conclusion? Move along, folks, nothing to see here …
[UPDATE – Steven Goddard points out below that the USHCN does in fact include a UHI adjustment in their data. The adjustment is detailed here. I don’t agree with the adjustment, because inter alia they claim that the UHI reduces the maximum temperatures in cities. This is contrary to my personal experience and to many studies that find it is hotter in the cities during the daytime as well as at night. But they do make an adjustment.]
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Larus (02:51:21) :
Hang on, do you actually think the entire problem is about how well the human body can withstand an ambient temperature rise of several degrees?
——————-
Reply:
What rise?
What year did climate science start using the 30 year climate benchmark to produce the temperature anomalies?
One of the best posts I’ve seen in a very long time.
Two of the things to watch on ALL graphs are (1) where is the zero on the Y scale, and (2) what is the Y scale compared to the X scale. The Sea Ice extent on WUWT side panel is a good example. If you show the Zero on the Y scale and half the scale on the Y scale, the graph looks completely different, as you have said, “nothing to see here, move along”.
I recently saw a comment on a blog accusing the author of deception because he had plotted some temperatures not as anomalies, or with a displaced origin at 14 degrees C, but as actual temperatures relative to zero. This somehow gave a ‘distorted’ picture of the gore-bull warming threat.
So, Willis, could I suggest that you show us a plot of HADCRU, GISS, NCDC, USHCN, GHCN or similar annual mean temps, not as anomalies, but as actual graphed temps, with a zero visible on the graph/no displaced origin. e.g. the annual means of your figure 2 above.
For me, the straight line so produced is instructive for us mere mortals, as it starkly shows the temperature increases we experience.
Kate (02:12:25) :
A leaked document has revealed the US government’s strategy in the UN climate talks. […]
• Increase use of off-the-record conversations.
What we need are more on-the-record conversations where people own up to what say.
These are very good graphs. Perhaps, just for the heck of it, one might include a similar zero or 280ppm based chart of CO2 concentration over the time period that we have reliable data.
In any case, I think these charts are a must-see for anyone making decisions of public policy on climate change or who is influencing public opinion on the subject.
Cold Englishman (03:33:03) :
Two of the things to watch on ALL graphs are (1) where is the zero on the Y scale
Zero F or zero C is meaningless, so you must mean zero K, and that would put things in perspective. On the other hand, chemical reaction rates typically double when the temperature increases 10 C [in the normal temperature regime where we live], so in terms of things happening around us the zero K origin doesn’t look reasonable.
For the uninformed
why are temperature records never shown as means plus minus 2sd (for say the last century)
rather than anomolies from the ‘normal’ warmish period of late 20th century?
Some of your graphs look just like the rise an fall of Al Gore.
And now for some humor.
The trying to get away from reporter and try not to answer questions trick.
http://www.climategatecountryclub.com/video/fox-confronts-al-gore
A little perspective is a wonderful thing. Nice article, Willis. Thanks!
Matt (02:52:32)
I love how people on the web are so quick to tell me what I don’t understand. I do understand that temperatures in Alaska are controlled by the PDO. I also know that they have not risen by anything like 4°C as you claim, and that rather than being 4° above where they were 50 years ago, they are currently about where they were 50 years ago. Here’s the record:
Alaska Temperature Average from First Order Observing Stations. DATA SOURCE
You also say that “if large areas of permafrost thaw” we’re in deep trouble … but the world was a couple degrees warmer earlier in the Holocene, and somehow we didn’t get in trouble. And if “large areas of permafrost” are thawing in Siberia, and melting permafrost causes huge methane releases … then where is the spike in the atmospheric methane content? Here’s that record:
Finally, you say if you posted other things here they would be “outright rejected as alarmist propaganda” … well, if they are anything like your alarmist propaganda about Alaskan temperatures and methane, you are likely correct about their probable fate.
Matt (02:52:32) :
“Just an example, Alaska and western Canada have warmed 3-4 deg C over the last 50 years”
Alaska experienced a ‘step’ change of 5 degrees in 1975. There hasn’t been any warming in Alaska since. Some would call it the ‘Pacific Oscillation’. We don’t have enough data to conclude that there is currently ‘cooling’ in Alaska, as the Oscillation is on a 30 year cycle. The fact that arctic ice is growing is a ‘sign’.
Sera (03:24:22)
Yes, and if it were ten times as wide as it is tall, it would hardly be scary at all. Which is my point. The graphs which are normally presented in the climate discussion are designed to look scary, as I have purposely done in Fig. 1.
Chuckles (03:36:33) :
You mean like these:
http://www.robertb.darkhorizons.org/WhatGlobalWarming.htm
My favorite is Red Bluff, 1875 to present, the UHI Slayer.
What a roaster 1875 was. Not only did they get a hot Indian Summer (fall) they got an equally toasty Indian Spring.
Pass the barbeque sauce.
Yes, I second the motion to end the use of anomalous graphs. Yes, pun intended. [:)]
By the way Willis, excellent article.
@Matt
‘Just an example, Alaska and western Canada have warmed 3-4 deg C over the last 50 years,’
Disregarding the mystery of the ever vanishing temperature measurement apparatus’, but warmed 3-4 deg C compared to what? What timeframe was used to calculate that baseline? And what different types of convenient observed temperatures and proxies were used in the cut and paste frenzy?
And besides, local weather phenomenon, is just that, weather.
One of the worst examples of using graphs to distort the truth is in the IPCC Technical summary figure 6, repeated in Archer and Rahmstorf (The Climate Crisis) as their figure 3.1 (but incorrectly referenced). This claims that, because the rate of temperature rise for the last 25 years of the 20th century was higher than the 150 years average, the rate of temperature rise was accelerating. This ignores the fact that in any long sequence with rising and falling temperatures there will be periods when the short term rise is higher than the average and that similar rates of rise were recorded from 1860 to 1880 and from 1910 to 1945.
http://www.climatedata.info/Discussions/Discussions/opinions.php?id=1209170702266403374
An alternative strategy is not to show graphs if they don’t tell the story you want people to hear. The IPCC TAR4 has two very small graphs of simulated and observed temperature and precipitation anomaly. What they don’t show are graphs of temperature relative to zero and precipitation in mm, which tell a very different story with temperature difference between models of 1.5 C and precipitation difference of 150 mm.
http://www.climatedata.info/Temperature/Temperature/simulations.html
http://www.climatedata.info/Precipitation/Precipitation/global.html
The standard anomaly procedure is designed to create a graph that looks worrying. If it didn’t, they’d find another way of processing and presenting the data.
Primarily there is the issue of scale to consider. The first graph presents the “anomaly” conventionally, by using a convenient vertical range to represent the slope, and cherry picking that range exaggerates the slope. If you present the anomaly scaled against the actual range from minimum to maximum temperature, the linear temp. anomaly line will appear virtually horizontal. The slope would be virtually imperceptable. Even the actual temp line would have minimal variation.
The other question is, if CO2 acts to make the atmosphere trap and re-radiate more heat downwards, why does the “more” only show up in winter outside of the tropics? Is tropical CO2 broken? Is the rest of the stuff on the fritz and only works to give us “more” when it’s cold? Answers worked out on the back of a peer-reviewed cigarette packet only, please.
@Matt,
How did you define permafrost ?
“……… – the very definition of permafrost means ‘permanently frozen.’ …”
Surely most of the land you describe as “permanently frozen” should more properly be defined as “recently frozen” or “become frozen in the last (approx) 800 years”.
Matt (02:52:32) :
How long does Methane last in Earth’s atmosphere?
@ur momisugly aylamp (01:59:37) : Tufte is a very smart guy. I once had the honor of attending one of his seminars, and chatting with him afterward. Quite inspirational. I have a framed copy of Minards’ “Napoleons March to Moscow” hanging in my den also, to remind me of what constitutes good practice.
Willis – please can you check out Paul’s comment above at 2:44:20?
I think he is right – adding another Jan point on the RHS of the graphic will make the gradients on and off the graphic compatible.
Willis Eschenbach (04:19:07) :
What I have hard to swallow is to put all the planet into one temperature average of up or down when the data stations are unproportional and the variations from region to region can differ significantly by how much precipitation or draught has occured which also has some influence on the temperatures of that region. From the equator up to the poles just on a world rotational map shows clearly 2 regions of climate by the movement of the cloud cover that does not cross the equator.
Willis:
Elegant. I also like the cool calm waterfall effect as opposed to the panic-stricken desert effect. Context is part of the message.
As someone said, Tufte’s one day seminar is well worth the money plus you get copies of all his books. I went with my team of survey folks – we do large scale surveys – and it had a significant impact on how we design client reports, etc.
So, putting this whole thing down to simple terms:
Let’s see now … the average low temp for Valentine’s Day here is 18° F, so around 14 February 2060, I can expect that, if it’s an average day, I’ll walk out to a morning temperature of approx. 20° F.
*yawn*
I’m going back to bed …