Guest Post by Willis Eschenbach
[See Addendum at the bottom.] [See Second Addendum at the bottom]
I got to thinking about the distribution of the so-called “global” warming. I’d heard that a good chunk of it was due to increasing nighttime minimum temperatures. So I grabbed the Berkeley Earth land-only temperature dataset. It has its problems, and I suspect the overall warming trend is exaggerated, but at least it is internally complete and consistent. I wanted to know both where and when the warming is strongest, and where and when it is weakest. I used the post-1900 data because prior to that the error bars get pretty wide, but the choice of starting point doesn’t make much difference.
For my first subdivision in time and space, I looked at the daytime maximum and the nighttime minimum temperatures by hemisphere. Figure 1 shows the result:
Figure 1. Maximum daytime temperatures (orange/red) and minimum nighttime temperatures (dark/light blue) by hemisphere. Data goes from 1900 through 2014.
This shows that as a hemispheric average, the nighttime minimum temperatures are rising faster than the daytime maximums, and that the northern hemisphere nights are warming the fastest of the four groups.
(I note in passing that while both the northern and southern hemisphere daytime temperatures dropped strongly from about 1945 to 1975, the corresponding drop in the nighttime temperatures is nowhere near as large. No idea why … always more questions than answers, gotta love that, but I digress …)
However, that wasn’t quite what I was looking for. I wanted to know more details about exactly where and when the warming was going on. So I made a couple of movies. Since the fastest warming is in the night-time, here are the century-plus nighttime minimum temperature trends, on a 1°x1° gridcell basis:
Figure 2. Berkeley Earth month-by-month average minimum nighttime temperature trends, in degrees C per decade.
This is what I was looking for, the details of the location and timing of the warming. The Northern Hemisphere nighttime temperatures are increasing the most during the winter in Siberia and Canada. And similarly, in the Southern Hemisphere the nighttime warming is greatest in the winter, although it is more evenly distributed spatially. Meanwhile, there is little trend change month-over-month in the tropics.
Now, call me crazy, but I don’t recall anyone ever saying “Boy, I sure wish that the February nights in the Yukon were colder” …
What about the daytime maximum temperatures? Figure 3 below shows the days:
Figure 3. Berkeley Earth month-by-month average maximum daytime temperature trends, in degrees C per decade.
Curiously, or perhaps not curiously, this daytime view shows the same pattern as the nighttime temperatures. The warming is concentrated in the extratropics in the winter.
Conclusions? Well, the most obvious conclusion is that the “global” warming is not global at all. Instead, it is strongest at night in the winter in Siberia and Canada. I’m pretty sure the poor people in Murmansk are not complaining about that …
In addition, there are large regions of the earth where for one or more months of the year, over more than a century the temperatures have actually cooled … the entire southeastern US, for example, is now colder in January than it was a century ago, both during the day and at night. If nothing else, this highlights the complex nature of the climate.
That’s what I see so far, but there’s much more to learn in the movies …
Clear weather today. I’m off to build an outdoor viewing tower so our cat can survey its domain … got to take my shirt off and saw up some wood in the sunshine, we melanin-deficient folks need to get our Vitamin D.
Best wishes to you all, whether you are in sunshine or rain,
w.
Addendum: I was accused in the comments of suffering from hypo-Europhilia, as evidenced by my Pacific-centered movies. Hey, I’m a tropical South Pacific boy, guilty as charged, so here’s the new movie:
Second Addendum: A commenter asked how well the climate models do at reproducing the patterns shown above. Here are a comparison of four different months (Feb, May, Aug, Nov) of one single GISS-E2-R model run from the KNMI dataset:
I don’t find the agreement particularly compelling, but YMMV.
Data: I got the Berkeley Earth temperature data from the marvelous KNMI site. Click the link entitled e.g. “1833-now: Berkeley 1°” and look down at the bottom of the resulting page for the gridded NetCDF dataset.
PS: I am reliably informed that it is no longer politically correct to refer to so-called “white” people as being “melanin-deficient”, as it implies that something is wrong with them. The new politically approved term is “melanin-challenged”.
My Usual Request: If you disagree with me or anyone, please quote the exact words you disagree with. I can defend my own words. I cannot defend someone else’s interpretation of my words.
My Other Request: If you think that e.g. I’m using the wrong method on the wrong dataset, please educate me and others by demonstrating the proper use of the right method on the right dataset. Simply claiming I’m wrong doesn’t advance the discussion.
Looks to me like warming is greatest in those areas that you would expect to be both cold and dry.
Humid areas aren’t seeing much warming, which you would expect because water vapor is such a strong greenhouse gas.
What was surprising to me was that a hot and dry area like the Sahara should so little warming.
There is far more water vapor in the air on a hot day in the Sahara than a cold night in the arctic. The shores of the Red Sea and the Persian Gulf have the highest absolute humidity levels of anywhere in the world.
Thomas
This has been bugging me ever since I passed through the Suez canal several times. 102 degrees in the shade,high humidity and still. Why doesn’t it rain?
Siamiam,
Hadley Cells …
https://www.seas.harvard.edu/climate/eli/research/equable/hadley.html
And no mountains.
Siamiam, there are two important measures of humidity. Absolute humidity and relative humidity. Absolute humidity is the water content of the atmosphere. The relative humidity is the water content of the atmosphere respect to maximum water content, and maximum water content increases greatly with temperature. The poles have low absolute humidity and high relative humidity. When relative humidity goes above saturation rain is possible if nucleation particles are present. Hot deserts have high absolute humidity and low relative humidity. Water content, albeit higher, never goes above saturation point.
siamiam, the high humidity there exists only in the very thin surface layer. A short ways up, it’s very dry…..
More warming in cold dry areas is what you would expect from increased CO2, as in those areas CO2 has less competition from water vapor.
My impression of that excellent visualisation is to see a 0.1C trend and a bunch of natural variation.
Forced air central heating became much more common during the mid 20th century. Prior to that gravity fed systems (or worse) were much more the norm for most of the built environment. Other sources of energy flux at or near the ground have obviously grown exponentially since mid century.
I suspect that global warming is strongest in Siberia and Canada due simply to human activity on the ground, when you open up 3000 acres for strip mining things tend to warm up, (urban heat islands aren’t the only kinds of heat islands). We also tend to measure temperature closer to where humans are active, rather than in remote/isolated areas.
I, for one, can attest to the differences attributable to a black asphalt driveway as opposed to a gray concrete drive here on the 45th parallel. Small changes can make a huge difference.
I don’t think so Mark. I think the effects are much bigger than the small contribution from humans.
I have looked at Environment Canada (EC) data from Alert (82N) to Eureka to Igloolik to Rankin Inlet to the Canadian border (49N). The same signal is in most locations. In fact, what I see in many cases is DECLINING maximum temperatures and LESS cold temperatures – so a convergence (In many but not all). In addition, geography, lake effects, ocean effects, elevation, etc, etc, etc all have influences. The Rocky Mountains cause a huge effect on what happens in British Columbia versus Alberta and as you move east the influence of Hudson’s Bay and the Canadian Shield appears to have a large effect. That’s weather of course , but isn’t long term weather climate? I have been alive long enough to have seen more than two 30 year “climates”. There is no way that I would consider the period 1980 to 2010 to be “CLIMATE” in my region.
My engineering studies told me to get the longest available record, and then go out in the field to proof it in case there was evidence that the data record was insufficient. And often the field proofing showed the data to be inadequate. For example, stream flow records and evidence of past flooding – usually the past flooding evidence was the real indicator.
My great grandmother was born the same year Canada was born – 1867. I trust her recollections of the climate in our region from when she was young a lot more than the last 30 year forecast from EC.
Bob Tisdale covered a lot of this in his book – On Global Warming and the Illusion of Control. Not promoting his book. However his section on DTR struck a cord with me as does Willis’ presentation.
One of the first holes I saw in GHG “science” was the lack of any discussion of change in temperature variance as opposed to mean . It’s one thing to change a mean , but quite another to change the variance , that is , the inertia . Increasing CO2’s coupling of surface heat to the atmosphere could change the inertia , but only changing our spectrum as seen from outside can change the mean .
Willis
Curious if the “Cold war”/fall of the USSR had a significant impact on apparent global warming. vis
Jason Calley commented:
I have not seen any official reports either way on this though I have heard of the hardship caused by coal fired heat not being turned on until a prescribed date regardless of the temperature.
If true, terrific story. Nothing I would ever have thought of. Humans have a way of adapting.
Honestly, I think it’s from all the persistent contrails acting as a heat blanket. Remember how temperatures at night went down after the 9/11 no fly time?
ls it possible there has been a decrease in the amount of blocking highs present in these areas over the long term. With this happening it would likely lead to warmer nights.With a decrease in cold clear nights and a increase in cloudy and windy nights. This would also explain the lack of warming in daytime temps during the summer months, eg a decrease in hot sunny weather and a increase in cloudy cooler weather. What is also interesting is the cooling during Oct/Nov. This may suggest that during these months there has been a increase in high pressure. So allowing the cold to set in more early
I’m confused. I thought the general standard for recording temps was max and min for the day. I assume there are some sites that may record more but what is the distribution of those sites? Just wondering where and how Berkley got the data.
I live in Saskatchewan, in the middle of the illustrated max warming zone in western Canada. A number of issues come to mind that I think may be relevant. This area was quite sparsely populated in the early twentieth century. I wonder about the accuracy of readings taken in the middle of the night, in the middle of winter, at small stations. If those guys had to go out to check temps in the middle of the night, in the middle of winter, what is the probability that they caught the ovenight minimum? Not a chance. And doing it for joe stalin in siberia? Go ahead, shoot me!I have personally seen temps below minus fourty in DEC., Jan., and Feb. Not sure what they think in Murmansk but we would be OK with some global warming
The guys who used to record the temps at the DEW line stations are on record as having said that many a night in the winter especially, readings were taken by the nose-out-the-door method that by actually bundling up and trudging out to the thermometer. This came out in the late 60s during some renewed interest in arctic and sub-arctic ecology. My own, “uncalibrated” anecdotal and semi-scientific observations from many years of field assessments of mammalian ecology leads me to easily conclude that the margins of error for temp readings is much, much higher than physicists and some mets would have you believe. There are so many uncontrolled situational variables to the site network that haven’t been adequately characterised, that while the data may show a trend increase in temperature, what has not been evaluated is the actual, rather than statistical, margins of error. in the network.
There is nowhere near enough discussion on the factors that perturbate the temp readings, and way too much emphasis on the temps themselves. We can show a trend increase in temperature. Whoop-tee-do. At this point, the discussion begins to fail dramatically. The physicists and climate alarmists fall back on simplistic textbook discussions that mumble about CO2, and other single cause excuses. At this point the response to an upward temp trend, in and of itself, should be no more than “so what?”. There is so much very big, very difficult, very expensive research to be done on the perturbers of the temps, rather the actual temps themselves, that an upward temp trend remains little more than a curiosity.
That should have been “factors that perturb”. “factors that perturbate” somehow sounds un-social even if it more closely reflects what has been done to the data…
Exactly! Nowadays, these readings are taken remotely and logged by a computer so it’s no skin off anybody’s nose ( literally) or any other body parts
Willis,
Surely you recall E.M. Smith’s work on the great thermometer die off in Siberia about 5 years ago. The rising temps in that region are quite possibly due to substantial reductions in stations by latitude as the more northerly stations were eliminated from the GHCN. Even the Russians complained at the time.
Fred,
The satellite data also show that “global” warming was mostly in the North for the past 37 years.
taxed February 23, 2016 at 4:38 pm
Anything is possible … but then, it may not be probable … I truly don’t know.
w.
Willis thanks for the reply.
lts what has happened during Oct/Nov in Russia is what is the biggest clue for me that this maybe the case,
Because had there been a increase in blocking during this time. Then l would expect there to be cooling in northern Russia but warming in southern Russia. Due to the difference in how long the days are and how high the sun is.
This is good stuff but it’s not really news to those of us who spend a lot of time in northern Canada. You can’t really talk about warming, but you can say that (anecdotally and based on personal experience) the winters have been getting “a bit less cold” since the 1970’s. Except in the last few years (before the current El Niño) there seemed to be a bit of a reversal, with maybe a cooling trend emerging, e.g. more -40°C mornings than we’ve seen for a long time, Lake Superior freezing over two winters in a row.
All the above unsubstantiated by instrumental measurements!! Maybe I can get a job as a climate scientist!!
Saskatchewan here and certainly I remember more severe winter storms when I was a kid in the 60’s. Lots of snow and flooding in the 70’s, hot and dry in the 80’s, back to cold and snowy in the 90’s, pretty decent winter weather through most of the 2000’s and finally- 2012 was one of the worst winters I have ever experienced and 2013 was very snowy and a little less cold and we had serious flooding again- to the extent that we have a few new shallow lakes that have persisted for 3-4 years now where no one ever identified lakes before in over 100 years.
Very warm winter now with the current el nino. Next couple of years might be tough
John – another Saskatchewan moment: do you remember the panic when Old Wives Lake was shrinking from a lake to a pool and people were panicking over “Global Warming”? Then they discovered tree stumps in the bottom of the lake indicating the lake bed had previously been dry for enough years to support trees – at least what passes for trees in that part of Saskatchewan. Remember the Palliser Triangle? What is old is new again.
Yes Wayne, and now Old Wives’ is risen to the point that roads are cut off in the area and local farmers are pleading for compensation to offset the many thousands of acres of land flooded out. Hang on though, help is on the way in the form of an incredibly long and snowless winter which may lead to a much drier 2016. Smart farmers around here just throw the dice every spring. Takes a real climate genius to spot the pattern here
Willis,
Surely you recall the work done by E.M. Smith on the thermometer dropout from the GHCN in Siberia. Many of the most northerly stations were eliminated. This may be the cause of the regional warming you have identified. Even the Russians complained at the time.
Willis, you said “I got to thinking”. This has got to stop, you hear! Might upset the “conventional warmist vision”. Can’t have that. Enjoy your posts. Always interesting. -E
I meant, “conventional warmist wisdom”.
Also, the historic high for our province was 47C or 115F in 1937. For those who think we live in igloos. Hot and dry in the thirties as well as the 80’s_ 1880’s and 1980’s. Post major el nino periods I would guess. Expecting hot and dry now that this el nino is disintegrating. I’m also wondering if the historical record supports the existence of a prior pattern of major el Nikos as per the sequence 1980, 1997, 2015
El Ninos, sorry. Major el Niko is just a guy I served under in the Greek army.
Johb Harmsworth: I worked in Northern Saskatchewan for about 13 years, 4 in Prince Albert. I experienced many many winter days of minus 40 C in the late 70’s.
The late 1800’s were very cold in Alberta and Saskatchewan. I have old records for a number of places along with the old exploration records from the Yukon at that time. People were tough back then as they didn’t have fossil fuels to heat their houses or even insulation in the walls. I remember days on the farm when things froze inside the house and frost grew on the inside of the logs.
I have experienced 50 below C. I have nearly frozen to death on several occasions and bear the scars. I’d be happy not to experience it again. A couple of degrees warmer – big deal.
The old joke of Canada having two seasons isn’t too far from wrong:
“6 months of winter and 6 months of bad sledding.”
Go Riders.
Interesting to a fellow rider fan, wayne. thank you. The guy who said winter lasts 5 months was what we call an optimist. However, I have read that years with high snowfall levels actually tend to bring an earlier melt, as the ground temperature stays warmer throughout the winter. Snowfall levels in Southern sask are pretty variable but most years, what falls-stays, until spring melt. So some years we may get -30 temps with little snow on the ground and frost may penetrate 6′, whereas other years we get snow early and frost doesn’t get deeper than 3′. This has a significant effect on snow melt and ground thaw in the spring. Tricky phrase around here but-negative feedback! Tough winter means early spring- at least to some extent. Different farther north in the boreal forest as well. And- go riders!
John – many great memories of snow in Saskatchewan. When I lived in Regina we used to say we got the same snow 6 times a years. It blew in from Medicine Hat 3 times a year and then it blew back from Winnipeg another 3 times a year. Talk about albedo effects. Prairie Schooners was an apt name for those of who have seen the waves carved into prairie snow and tried to drive up a remote country road through those “waves”.
I wonder if the start of extensive ice sheets is the presence of abnormal warmth? Did the Medieval Warm Period actually serve as the beginning stages of a plunge into an ice sheet growth? Does the blob’s presence help set this up? Does the pattern of warming nights actually tell us we have ice sheets coming? I know it seems to be an oxymoron that warm means cold but when it comes to a loopy jet stream warming parts of the Earth and colding other parts in a pattern eerily similar to the extent pattern of ice age ice sheets, it does make me go “hmmmmmmm”. My imaginative mind can see continued episodic El Nino waters that end up accumulating in the North Pacific Gyre causing that blob to be a fairly permanent part of the coastline, setting up a long term loopy polar vortex that buries the Eastern half of the US in a very cold and very deep ice sheet.
http://climatechange.cornell.edu/what-is-a-polar-vortex/
Basically then, is it the western warmth that heralds the eastern cold of growing ice sheet behavior?
There may be something to this. Consider this. Looking at the West Coast, I don’t see much evidence that the Cascadian flora ever extended much beyond where they are now found. I also don’t see evidence of the California open and semi closed hardwood having extended much beyond where they are now. From this, I must wonder if in fact, during the Pleistocene, we were actually drier than now. Perhaps colder, yes, but also, perhaps, drier. And the current extents are actually Holocene features, wrought by a warmer and wetter climate.
With a large mass of water from oceans being converted to ice, it is not surprising to find some areas drier.
There are many regions of the world with much “loess” (wind blown silt) cover.
I’ve lived at the edge of one: (from Wikipedia): “The Palouse Hills of eastern Washington and northern Idaho is a fertile agricultural region based on loess deposits.”
A search of ‘ images ‘ is advised.
Forgive me if anyone else has said this already but isn’t the elephant in the room the fact that the warmer nights are restricted to the extra tropics in the winter months and the early months of spring. Surely, if CO2 was the cause of the increase in night time to day time temperature anomalies with time then it should be taking place at all latitudes through out the year.
In the less populated areas, wood heated residences tend to cool off during the long winter nights as people go to bed early and burrow under covers rather than get up to feed the wood stove. Modern heating with propane or whatever keeps residences warm all night. So over time that is an extra heat source near the monitoring station that might amount to something. But more importantly, if you replaced the woodstove with oil or gas and aren’t chopping down trees in the immediate vicinity for wood heating, trees are now growing up and blocking IR paths to the night sky, making it warmer at night.
That’s a difficult argument to make, in the context of subsistence heating. The amount of wood removed from the woodlot, relative to the replacement growth, isn’t going to change the net impact of the woodlot very much. Early users of wood for subsistence heating were usually quite well attuned to sustainability of the woods, much more so than urbanites. It’s not until you get into commercial clear-cut practices over a fairly large area that impacts are likely to be significant. Having said that, “butterfly hypothesis…” 🙂
Agreed, the area showing influence is sparsely populated and home to literally billion of trees. Human impact was and still is negligible.
Willis,
This is an excellent article. Very well researched and written and it makes that excellent point that the global warming of the past many decades hasn’t really been global.
I commented about the same phenomenon at your earlier article here http://wattsupwiththat.com/2016/01/19/whats-hot-whats-not/ at 6:50 pm.
“[R]ecent warming isn’t global at all. The same pattern can be seen in the UAH [satellite temperature] data. The data show no warming at the south pole, almost no warming in the southern extra-tropics, very slight warming in the tropics, slight warming in the northern extra-tropices, and several degrees of warming at the north pole.”
You wrote:
“I note in passing that while both the northern and southern hemisphere daytime temperatures dropped strongly from about 1945 to 1975, the corresponding drop in the nighttime temperatures is nowhere near as large. ”
It seems to me that increased cloud could be a cause of that. Cloud cools days but keep nights warmer.
Unfortunately I have no link, but during the past few weeks I read an article in which Russian scientists said that the temperuture difference between Siberian cities and their surroundings has increased over time to 8 to 10 deg. C due to more and more leakage from the district heating systems. These scientists also said that probably the only place where global warming exists is in the IPCC offices and reports so could very well have been an article here at WUWT.
Willis, interesting post.
When looking at your Figure 1, it seems that since 1970, nighttime temps have NOT increased more than daytime temps, not in the NH, but especially not in the SH. It appears it all happened between ~1920 and 1970. To me, this is your main find, because it really doesn’t make any physical sense at all …
A positive trend of minimum temperatures in Arctic regions is a clear sign of UHI. Here in Sweden, the temperature outside the city of Uppsala can be up to 10C colder than within the city in cold and clear winter days with no wind. This effect can be present in relatively small cities and it is probably very difficult to eliminate this error from the temperature series.
Kristian … That’s a good point.