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.]
RE Street (06:04:18) : “But the Fahrenheit scale is itself arbitrary! That is why the Celsius and Kelvin scales were developed. Granted, Fahrenheit is the best scale for communicating with Americans …”
While the Celsius and Kelvin temperature scales are the adopted scientific standards, the Fahrenheit scale is, in fact, potentially more accurate for data recorded as integer values because of reduced round-off error. Of course, if they make their measurements right next to an air-conditioner outlet, no advantage is gained.
Matt
Impressive Isn’t it? Just drop the northern and high elevation stations (documented previously here at WUWT) and suddenly huge warming in western Canada.
Heck those stations were inconvenient to monitor, way too darn cold.
stevengoddard (06:21:20) :
“The US only makes up 2% of the earth’s land area.”
USA is 6.15% of Earth’s LAND area: 9,161,966 sqr km cf 148,940,000 sqr km
In May 1969, U Thant of the United Nations gave the planet only ten years to avert environmental disaster; the following month, he blamed the bulk of planetary catastrophe on the United States……Some things don’t change as much as weather
I have presented this approach, and others (show the full max to min range for each year) here cdnsurfacetemps.blogspot.com. When you look at the full year range per year what you find is the trend in the summers is for cooler temps, while the winters are not as cold. Thus the temp range is converging. At some 700 years into the future the two trends would meet, meaning the summer and winters would be the same temps, and there after the winter warmer than the summer.
Since this is physically impossible, these converging trends must at some point change and start to diverge. In other words a cycle. Thus this temperature change cannot be from our CO2.
Which is confirmed in this paper from 2000:
http://www.cmos.ca/Ao/articles/v380301.pdf
where they conclude:
“Like other parts of the world, Canada has not become hotter (no increase in
higher quantiles of maximum temperature), but has become less cold.”
and they note at the end AGW can’t account for the temperature changes in Canada.
Thanks for this Willis. It is always good to see data in a contextual perspective.
stevengoddard (06:21:20) : your link’s graph hurt my eyes to look at it, so I tried to reproduce a better one using GISS US 2008, vs. Hansen’s re-evaluated global land/sea, and got something completely different. No divergence, Jimbo has managed to match the globe to the US. Another cute trick.
http://i40.tinypic.com/2ih0ylw.jpg
It seems like I have been reading comments and posts from Willis ever since I started following climate blogs about five years ago. His writing style is clear and he can tell a compelling story.
Willis, is it about time for a book, or is there one out there I haven’t heard of? BTW, I really like the way the graphics are presented. The photo slide format just looks neat.
Thanks for the years of entertainment and learning. I hope to be reading your stuff for a long time.
On a scale of 0-100%, one part per thousand of carbon monoxide wouldn’t be visible. Who would want to sleep in a atmosphere with 0.1% CO? Data should be displayed on a scale related to its importance.
What goes into your bank account is less important than the difference between what goes in and what goes out. The difference between two numbers can be more relevant than the individual numbers.
Steven, that just makes me think that the rest of the worlds temp measurements are messed up.
And we know enough to know that’s a fact.
Willis:
I’ll concede the point about Alaskan warming – I got my figures from a 2004 report, so looks like things have changed a bit.
Regarding the methane emissions from permafrost thaw, that is a phenomenon that is just beginning – I never claimed that there would be a 100 fold spike in one year. However, our own graph shows a 12% increase in methane ppbv since 1980, so for you to claim that there is no increase is nonsense. Care to calculate the radiative forcing of 12% more methane in the arctic?
Anyway, my original point still stands – your claim that a 0.5 deg C global average temperature increase ‘is trivially small’ willfully ignores the implications of such an increase. Namely that in terms of a ‘global temperature average’ this is a very non-trivial increase. To claim otherwise is to demonstrate a misunderstanding of a global temperature average.
Steveta_uk (07:03:21) :
Much of the warming GISS claims is in central Asia. One theory is that the large landmass promotes warming, whereas the US climate is moderated due to being surrounded closely by oceans on three sides.
John (06:40:11) : It seems that your graph is “also” misleading. […] In essence, you are guilty of doing what you accuse the warmers of, presenting the data in a way that “appears” to support your views. Bottom line is that this is only useful for those who wish to see things this way. It does not show anything useful.
Au contraire, it puts the ‘catastrophic warming’ in perspective with normal variation. Even though the former is grossly exaggerated, it is still meaningless in the context of reality.
Bob (Sceptical Redcoat) (07:33:15) :
Good point. I meant to say the US makes up only 2% of the earth’s area.
Willis wrote:
“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.”
============
Excellent point. That is exactly what I think too. It is indeed a crucial piece of information whether warming occurs uniformly accross the entire temperature range, or mostly at the lower end of the range. And it is a piece of information that a mere averaging of global temperatures, however it is done, does not give at all. If it turns out that what little warming has occurred comes mostly from a rising of temperatures at the lower end of the range, and very little or no rising at the upper end, then the case for alarm seems even more outlandish. It’s hard to imagine people being awfully upset by slightly milder winters. A few may complain that winters are becoming insufficiently harsh, and the bitter cold is not quite as bitter, or doesn’t last as long, as in the good old days. But I suspect most people won’t miss those treasures all that much. Neither woud most animals and most plants.
By conflating mean temperature changes with annual seasonal changes this article pretends that there is no cause for concern. According to figure 1 the US has already experienced a temperature change roughly equivalent to moving everyone’s locality south by about 100 miles. It does not sound much and has not caused noticeable changes to most of us. However projected warming over the next century is equivalent to moving everyone about 500 miles or more south.
Clearly this will cause noticeable change; it is about the same distance from Chicago into Alabama, or from northern to southern France. I think most people would notice a change in climate if they made such a journey. It won’t be as obvious as seeing and feeling the changes that hit you when you get off a plane at the end of the journey because the change is coming slowly, equivalent to 5 miles/year, a snail’s pace.
The change is coming however. Slow for us but not for snails and other creatures which is why naturalists are concerned that the natural world will not adapt without considerable disruption.
Steve Keohane (07:49:41) :
Nice try. You used a centigrade scale for the global map and a Fahrenheit scale for the US map.
Excellent post. Thank you Willis.
Dr A Burns (02:23:52) : A variation of 1 deg F is equal to the recording accuracy of measuring stations: ☺ Add to that the UHI effect and it would be easy to argue that either
a) we have no idea what the temperature is doing (a good bet)
b) it is probably getting colder.
And as for Matt!? What is this “western Canada is 3 to 4C° warmer than 50 years ago.”
“Everyone” knows it was getting colder from the 1940s the 1970s (it was reported in Newsweek, remember? ☺) and all of the alleged warming has been in the past 30 years. Right? In the past twenty or so years, southern Alberta (not a small area) has either not warmed or become cooler considering mean annual temp.
Back to the “Alaska and western Canada have warmed 3-4 deg C over the last 50 years,” If we accept North American temp has increased (say) 1C° in the past century, and if we are to believe Matt, then golly gee, an area the size of ALL of eastern USA (east of a line from Minn to Louisiana) had to have cooled by 2 to 3C°.
So Matt, perhaps you can tell us which of some twenty US states have cooled by 2 or 3 C degrees to result in the “average” for NA.Thanks.
Again, a great item. Thank you Willis. ☺
Clive
From southern Alberta which remains under a storm advisory with up to 30 cm of snow forecast for some regions. We always appreciate the moisture.
stevengoddard (08:21:47) : Sorry you’re wrong, both are in °C!
stevengoddard (08:21:47) : Here are the original graphs:
http://i39.tinypic.com/denvrd.jpg
Steve Keohane (08:40:01) :
OK – I see what you did. The difference is which version of USHCN we used.
“However projected warming over the next century is equivalent to moving everyone about 500 miles or more south.”
At that pace, some people are going to hit the equator soon. Then where do they go?
Excellent post Willis. This must set a standard.
I wonder if the larger fluctuation which can clearly be seen in the Winter months is partly due to the amount of ‘fake’ heat in the air during this period? A Winter Urban heating effect would fluctuate in response to the weather and, of course, many people would keep some level of heating going through the night in modern times.
Matt, how much of the increase in methane concentrations occurred over the past 10 years? By looking at the graph Willis posted, it seems as if most of the increase in methane occurred from 1985-1995. Do you have a yearly graph that would clarify this for me?
stevengoddard (08:56:28) : Could you expound a little on the differences? I am not trying to be contrary, rather I was just trying to make a more easily read graph. I went through my files looking for the most recent GISS purveyance for US and global. Is/are the difference(s) adjusted vs. not? Your reference at (05:27:36) to the pivoting of the x-axis may be a global phenomenon as it shows up in some NZ graphs shown here in the past few months. (another possibility for the alignment of my graphs vs yours?)
A very subversive post Willis. How dare you show a different perspective?!
Only joking..
I think an even more interesting comparison is the weekly or even daily range of temperatures with the overall the overall trend. Most of life manages to struggle through a daily range of >10C and weekly range of >15C. Kind of makes a 100 year trend of +0.75C seem like less than the end of the world.