In this post, we’re going to present monthly TMIN and TMAX Near-Land Surface Air Temperature data for the Northern and Southern Hemispheres (not in anomaly form) in an effort to add a little perspective to global warming. And at the end of this post, I’m asking for your assistance in preparing a post especially for you, the visitors to this wonderful blog WattsUpWithThat.
INTRODUCTION FOR THE “GLOBAL WARMING IN PERSPECTIVE” SERIES
A small group of international unelected bureaucrats who serve the United Nations now wants to limit the rise of global land+ocean surface temperatures to no more 1.5 deg C from pre-industrial times…even though we’ve already seen about 1.0 deg C of global warming since then. So we’re going to put that 1.0 deg C change in global surface temperatures in perspective by examining the ranges of surface temperatures “we’ve been used to” on our lovely shared home Earth.
The source of the quote in the title of this post is Gavin Schmidt, who is the Director of the NASA GISS (Goddard Institute of Space Studies). It is from a 2014 post at the blog RealClimate, and, specifically, that quote comes from the post Absolute temperatures and relative anomalies (Archived here.). The topic of discussion for that post at RealClimate was the wide span of absolute global mean temperatures [GMT, in the following quote] found in climate models. Gavin wrote (my boldface):
Most scientific discussions implicitly assume that these differences aren’t important i.e. the changes in temperature are robust to errors in the base GMT value, which is true, and perhaps more importantly, are focussed on the change of temperature anyway, since that is what impacts will be tied to. To be clear, no particular absolute global temperature provides a risk to society, it is the change in temperature compared to what we’ve been used to that matters.
Anyone with the slightest bit of common sense knows that, annually, the local ambient temperatures where they live vary much more than the 1-deg C change in global surface temperatures that data show Earth has experienced since preindustrial times and way much more than the 0.5-deg C additional change in global mean surface temperatures the UN has set its sights on trying to prevent in the near future.
Please keep that 0.5-deg C in mind as you view the graphs and read the text that follow.
BTW, there were two posts at WattsUpWithThat about global mean surface temperatures in absolute form that preceded Dr. Schmidt’s post, and they may have prompted his post. The posts I’m referring to at WattsUpWithThat were Willis Eschenbach’s post CMIP5 Model Temperature Results in Excel and my post On the Elusive Absolute Global Mean Surface Temperature – A Model-Data Comparison. (WattsUpWithThat cross post is here.)
DATA SOURCE
The source of the data presented in this post is Berkeley Earth. WHY Berkeley Earth? In addition to furnishing their datasets in anomaly form, Berkeley Earth also provides monthly period-average surface temperatures in absolute form for the base period (1951-1980) they use for the anomalies. So with those monthly absolute values, it’s easy to convert the monthly long-term temperature anomaly data into absolute temperature values, which is what we want for this presentation. (And before someone complains about my use of the term absolute, it is commonly used by the climate science industry when describing temperatures in their observed, not anomaly, form.)
Near-land surface air temperature data for the Northern Hemisphere are found here, and for the Southern Hemisphere, they’re here.
Specifically, for this post, data for TMIN (Mean of Daily Low Temperatures) for the Northern Hemisphere are here, and for the Southern Hemisphere here. And for TMAX (Mean of Daily High Temperatures), the data for the Northern Hemisphere are here, and for the Southern Hemisphere here.
As a reference for a couple of graphs in this post, I’ve also included the curves of the monthly Berkeley Earth land+ocean surface temperature anomalies data…found here. There are two versions found on that webpage, I’ve used the data with air temperatures above sea ice.
AVERAGE ANNUAL CYCLES IN MONTHLY HEMISPHERIC TMAX AND TMIN
For the reference period of 1951-1980 used by Berkeley Earth, the average annual cycles in TMIN and TMAX for the Southern Hemisphere (90S-0) are shown in Figure 1. As noted below the graph, for the Southern Hemisphere and this time period, the difference between the highest TMAX and the lowest TMIN is 22.4 Deg C.
Figure 1
The average annual cycles in TMIN and TMAX for the Northern Hemisphere (0-83.5N), again for the reference period of 1951-1980, are shown in Figure 2. For the Northern Hemisphere and this time period, the difference between the highest TMAX and the lowest TMIN is 34.9 Deg C.
Figure 2
HOW SURFACE TEMPERATURE DATA ARE NORMALLY PRESENTED
Normally, global land+ocean surface temperature anomaly data are presented in anomaly form, with the scaling of the y-axis as tight as possible to make the long-term and short-term variations appear large, when, in reality, they’re very small…so small you’d never notice them if it wasn’t for the constant browbeating from politicians, the mainstream media, and members of the publically funded climate data and modeling businesses, which have to keep their funding alive.
AND NOW FOR SOMETHING COMPLETELY DIFFERENT (Thank you, Monty Python)
With that in mind, Figures 3 and 4 compare (First) the monthly global mean land+ocean surface temperature data in anomaly form (black curve straddling zero degrees C) with (Second) the monthly TMIN (Mean of Daily Low Temperatures) and TMAX (Mean of Daily High Temperatures) data in absolute form for the Southern Hemisphere (Figure 3) and the Northern Hemisphere (Figure 4). The TMAX curves are in red and the TMIN curves are in blue.
Figure 3
# # #
Figure 4
But, Bob, I can hardly see the long-term and short-term variations in the global mean surface temperature anomaly data.
Bingo! That’s precisely the reason I went to all the trouble to prepare and present these comparisons.
Important Note: The hemispheric data from Berkeley Earth end in 2013, while their global temperature datasets continue to be updated monthly. I’m not trying to hide anything by ending the graphs in 2013 as some of you were thinking.
The data in the graphs begin in 1900, because the year 1900 is the last year of the IPCC’s new definition of pre-industrial times, which runs from 1850-1900. See the IPCC’s Changes to the Underlying Scientific-Technical Assessment to ensure consistency with the approved Summary for Policymakers from their 2018 Special Report (SR15). [End note.]
That’s it for the primary content of this post.
A LITTLE HELP, PLEASE!
I’m planning to continue this series of posts with graphs like the ones in Figures 3 and 4, but providing them for individual countries. See the example for Canada in Figure 5. (Brrr.)
Figure 5
I’d like to begin with the countries that visitors to this blog call home. I believe most visitors are from Australia, Canada, France, Germany, India, Ireland, Japan, New Zealand, Nordic countries, South Africa, and, of course, the UK and USA, because, if memory serves, you’ve mentioned them all in comments at one time or another. (Sorry if I missed your country.) And many of the posts are written about The UK, USA, Germany, France, and so on. Please advise me in comments so I can include them in the upcoming post (or posts, if need be). Please do, because we should be able to have some fun with this, especially those of you who use social media. (Imagine all of the tired old arguments you’d see.) If the list gets long, beyond 22 countries for the sake of a number, we’ll spread them out over a couple of posts.
And I assume many of you less-verbose visitors may be from many other countries. Maybe this will be the first post on which you’ll offer a comment. If so, welcome aboard.
That’s all, folks. Have fun in the comments and enjoy the rest of your day.
STANDARD CLOSING REQUEST
Please purchase my recently published ebooks. As many of you know, this year I published 2 ebooks that are available through Amazon in Kindle format:
- Dad, Why Are You A Global Warming Denier? (For an overview, the blog post that introduced it is here.)
- Dad, Is Climate Getting Worse in the United States? (See the blog post here for an overview.)
And please purchase Anthony Watts’s et al. Climate Change: The Facts – 2017.
To those of you who have purchased them, thank you. To those of you who will purchase them, thank you, too.
Regards,
It is a joy to watch the wriggling and squirming over a possible 1 degree in a century of warming especially from Nick and Mosh. Gotta blame it on something.
The truth that everyone seems to ignore was first mooted by Darwin and his ilk.
Every 20 to 30 years a new generation is born. That generation will adapt to whatever temperature and weather it experiences for 70 to 100 years . The generation 20 years behind will adapt and so on and so forth.
It is completely and utterly ridiculous to assume that humanity is fixed in time and will not adapt naturally.
Humans use tools to adapt and hence are more efficient at adaption than other animals.
This whole global warming scam is a complete crock of sh*t as it assumes that we are identical to our forebears and will remain locked in the present forever.
Ivor, in the old days, we simply would’ve accepted the variations in daily, monthly and annual ambient temperatures as Mother Nature at work, and we would have gone on with our lives without a second thought. Too many whiners in the world right now.
Regards,
Bob
Just eyeballing your charts, it looks like daily variations in temperature average about the same throughout the year.
Based on greenhouse models, I suspect that with global warming due to additional greenhouse gases, average daily temperatures should trend up while average diurnal ranges should trend down- less of a diurnal swing in temperatures. In contrast, if temperature changes were caused by factors OTHER than greenhouse warming, diurnal temperature swings should stay the same or get larger. LOCALLY, there WAS greenhouse warming in California’s central valley- caused by irrigation. In THIS case, AVERAGE temperature went up, but temperatures in the DAYTIME actually went down thanks to plant transpiraton- matching my supposition that with greenhouse induced global warming, diurnal temperature differences should DROP.
http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1195&context=natrespapers
As I said in my first sentence, average diurnal swings appear to have remained roughly constant. Has there been a swing in the RANGE of diurnal temperatures? As I said before, a DECREASING trend would imply warming caused by greenhouse gases. An INCREASING trend would be caused by something OTHER than greenhouse gases- such as fluctuations in sunlight, etc.
Bob, these graphs are excellent. A potential way to add further information and insight would be to include, for example, say the top 20 hottest Tmax temperatures in the data set (e.g., as solid dark red circles) and the lowest 20 T min temperatures (as solid dark blue circles). This sampling approach would indicate how extreme temperatures (hot and cold) are distributed over time — that is, do the data show a random pattern or a time-based trend, etc.
Bliss58, your suggestion would add complexity to the illustrations and take away from their intent.
Regards,
Bob
“To be clear, no particular absolute global temperature provides a risk to society, it is the change in temperature compared to what we’ve been used to that matters.”
Schmidt is indulging in mannsplaining.
Definition
mannsplain [man-spleyn] verb (used with or without object)
1. to pull something out of one’s arse and dogmatically assert it to be profound truth without reliable evidence for said claim.
e.g., Gavin mannsplained that change in temperature compared to what we’ve been used to is what matters.
Word Origin
Date of first use is unknown.
The term is a portmanteau of the words Mann and explain (similar to mansplain), which derives from the time Michael Mann pulled a hockey stick out of his arse and declared it to be proof of global warming.
Related forms mann·splain·er , noun
Thanks, icisil, I really enjoyed that. Made me laugh.
Especially, “…to pull something out of one’s arse and dogmatically assert it to be profound truth without reliable evidence for said claim.”
Cheers,
Bob
Bob (Tisdale), how much does humidity figure into what you are doing?
Just asking, becuase normally, winter humidity in the Midwest is low (+/-50%) but in the past few years it has steadily increased and stayed above that level, regardless of temperature. I keep track of this kind of thing.
Spring came VERY late this year.
Sara, sorry, I can’t answer your question with data because, as far as I know, it doesn’t exist in the same easy-to-use form and for the same locations. On the other hand, all of the hoopla is about temperature not humidity.
Cheers,
Bob
Sara,
PRISM climate explorer does vapour pressure here:
http://prism.oregonstate.edu/explorer/
Thanks. I keep track of both temperature and humidity.
What I notice is that now in the winter, as the temperature rises, humidity drops just slightly. The same thing happens in the summer.
This morning at 6:30AM CST, temperature was 14F and humidity 84%. I just took another reading at 10AM and temperatrure is 22F, humidity is 81%.
I find it to be true in the summer now, as well, so it may have some relevance to why things seem to be changing.
Wonderful thought provoking conversation that is essentially focused on data presentation and how it influences OPINIONS on the underlying data itself.
In that sense, I think Nick Stokes and Steve Mosher have the better argument here, IF we can only use one type of chart – but that Bob Tisdale’s charts ARE useful in a different way. Here’s why.
The single line anomaly chart preferred by Stokes/Mosher is by the far the best way to see trends, which is useful in many ways.
And Bob’s absolute TMIN-TMAS charts are by far the best way to understand the range of typical data values that have been occurring over time and whether or not that range is expanding or contracting. Bob’s chart is also useful if we know that the range of values is near some sort of “breaking point” in the environment where the data is being collected.
Do a mind game for a second and change the assumption on what is being measured from temperature to air pressure inside a sealed vessel of some sort, perhaps an airplane.
There is some upper limit on interior pressure in which the pressure vessel will burst from the inside. Likewise, there is a lower pressure limit in which it will be crushed from the outside. If we want to know how close we are to a catastrophe – AND IF WE KNOW THE BREAKING POINT OF THE SYSTEM WE ARE MEASURING – then Bob’s chart is clearly the best.
If we do NOT know the “breaking point”, however, then Nick and Steve’s is best, because it gives us a useful tool to see which direction change is moving and allows us to monitor for destructive changes, even if we do not know the exact breaking point of the system.
BOTH ways at looking at the data are valid. One is just more useful than the other depending upon our knowledge of the breaking points in the system we are studying.
In terms of the impact of Climate Change, I think we really don’t know for sure the breaking points of most things, including human life, animal life, plant life, ice sheets, coral reefs, etc., so therefore I like the anomaly method better.
The point goes to Stokes/Mosher, I think….
If I were an engineer, (and I was) this is the data presentation I would want to see first.
Useful conversation, though, and Bob is NOT wrong!
His chart is just useful in a different way……
Your idea of a “breaking point” in temps is frankly, retarded.
Isn’t the use of “breaking point” just another way to say the much feared “tipping point”?
Fun: Gavin’s own-goal about why it’s the “change in what we’re used to in temps” that’s the problem, not the measely 1 deg. rise in global temps since the LIA.
Funner: Nick and Mosh’s desperate attempts to climate-splain Gavin’s “logic”.
Funnest: Watching them dig themselves in deeper and deeper with each further attempt.
Bruce, fun, funner, and funnest! Made me laugh hard.
Nick and Mosh can’t seem to grasp that I am not preparing posts for them.
Cheers,
Bob
Thanks for the post Bob, it puts things into perspective a lot better. If you live in Finland like me then it is quite common to have max Summer temperatures of +30C and Winter temperatures of -30C. In fact the difference can be as much as 80C in some places. I don’t know what the average monthly min/max are but I would imagine the range to be quite high (>35C).
So perhaps another good measure would be to plot the min/max temperature differences by latitude (perhaps taking some key cities into consideration)?
Ouluman, that would be easier to do if the KNMI Climate Explorer website were to add the Berkeley Earth TMAX and TMIN data in absolute form, or if Berkeley Earth added some webpages that allowed users to select ranges of latitude and longitude like the KNMI Climate Explorer.
Maybe some time in the future.
Regards,
Bob
If have been a follower of this blog for over 10 Years and
I would love to see the Temp graph’s for The Netherlands.
jacques, the graph for the Netherlands will be in the next post.
Cheers,
Bob
It’s the change in temperature.
Oops, that didn’t work. Need to delete some of my wordpress shortcuts, which used to work. Maybe this will:
http://jonova.s3.amazonaws.com/graphs/lappi/gisp-last-10000-new.png
If a ~1 deg C rise over the last 100 years in surface air temperature has a very negative impact on earth’s living things and habitations (including people and their contrivances), would a 1 deg C decline have equally negative effects, even though they would be different effects ? Has anyone flipped the coin the other way and declare (with analysis), see, we would not be used to this either, and it is also very bad for reasons x,y,z ?
If so, then was the earth in a sort of ‘perfect’ state in terms of climate, 100 years ago, and either up or down is bad ? Context helps one’s thoughts on this.
Hi Bob,
Not sure if it is mentioned elsewhere in the comments, but when I see the Tmin and Tmax average graphs, it is apparent that the additional 0.5 degree rise means that the overwhelming majority of the time the “absolute” temperature will be within the range between them. You should run a calculation to quantify the percentage of time annually that will be outside of the present range of temperatures.
carbon-based life form, a great idea.
It should be relatively easy. I could add 0.5 deg C to annual cycle graphs, using 1981-2010 as the reference 30-year “climatological” reference period. Similar to Figure 2, but with “future” curves 0.5 deg C higher:
Easy to do.
Thanks for the idea. I’ll include those in my upcoming posts in this series.
Cheers,
Bob
carbon-based life form, below is a sample:
Comments?
Bob
Very appropriate start!
But, may I recommend the following? (Now, that’s not really a fair question, because I’m going to do it anyway, and there’s nothing you can do to stop me. But it is a polite fiction.)
Keep that graphic. Add a second graph with two year’s actual daily temperatures superimposed on those smooth “average” values. Show the wild temperature swings that actually occur every day, year after year, that nobody notices.
The vegetation in the southern hemisphere from May to September is inhibited.
Error bars at least 0.5 Deg C.
Beauty! The same way I consider sea level rise in relation to the current tides. The normal variation overwhelms the incremental changes. Looks like temperatures would exceed the upper bounds a few days each year, and the area under freezing would be slightly smaller. Not to say there isn’t a long-term effect, but certainly not imminent or catastrophic, I would think. And let me add my thanks for the time you spend on this important work!
Thanks Bob for the perspective.
Just because Gavin labels “Absolute temperature” as Celsius doesn’t make it so.
In science “absolute temperature” usually refers to the thermodynamic Kelvin temperature scale starting at absolute 0 K and the triple point of water as 273.16 K (recently redefined.)
See BIPM Thermodynamic Temperature
https://www.bipm.org/en/publications/si-brochure/kelvin.html
Natural blackbody radiation negative feedback varies as the absolute temperature to the 4th power.
I recommend showing graphs from zero Kelvin to ~350K to show how little Earth actually changes.
AND show blackbody radiation feedback as T^4th for perspective.
Similarly see Christopher Monckton’s correction to climate feedback equation back to the absolute scale.
Climatology’s startling error of physics: answers to comments
https://wattsupwiththat.com/2018/08/15/climatologys-startling-error-of-physics-answers-to-comments/
Note BIPM on Celsius:
Hi Bob
Guest Poster Kirye of Japan has some interest charts at the link provided below, showing an increase in the number of colder days in Japan – 1979 to 2018.
Regards
http://notrickszone.com/2018/12/08/surprise-co2-warming-signal-absent-in-japan-number-of-cold-days-rising-over-past-30-years/
If this simple sailor can clearly see the heightened temps in the 30’s and the pause, what does that say about Mr. Mosher’s eyesight and or his reactions to uncomfortable presentations that don’t meet his, apparently, preconceived notions of what is proper?
There is no escape from the winter stratospheric intrusion.
The stratospheric polar vortex is broken.
An excellent post.
To me the real comparison would take place in areas where there is a constant regional weather environment. Such an area could be Chicago urban area v the surrounding countryside. A similar areal example would be Melbourne, Australia where the CBD is known to be a ‘heat’ island compared to its hinterland. Both cities have condensed CBDs and both have extensive suburban (shoulder information) and non developed zones external to the main areas of development.
To fully cover the stated concern-
“To be clear, no particular absolute global temperature provides a risk to society, it is the change in temperature compared to what we’ve been used to that matters.”
I think a paper ought to be written that would address the various downsides for humanity if the temperature had swung negative the same amount instead of positive. Are there only upsides to slightly cooler weather ? I don’t think so, but the topic doesn’t get much treatment, since it is more of an academic exercise. But it still would still add to the discussion.
I’m not a climate scientist but I can read. So why does my climatology text book* take the exact opposite position to that of Nick Stokes and Steven Mosher above? They both have this whole tail wagging the dog thing going with their odd notion that a global statistic derived from local measurements is somehow forcing those same measurements!
Here are its conclusions, the concluding paragraph in fact [emphasis added]:
*Applied Climatology: Principles and Practice, By Allen Perry, Dr Russell Thompson, Publisher: Routledge Print ISBN: 9780415141000, 0415141001, eText ISBN: 9781134769124, 1134769121, Edition: 1st
I successfully read economic and financial charts, graphs, and diagrams. I left after figures 1 & 2 because I don’t know what 1 – 13 along the bottom means.
Hey Bob,
Talking about absolutes – below graph of daily Tmin for Boulder, CO, 1900-2018 (up to date) with superimposed range of trends based on the assumption that each reading has uncertainty +/- 0.5 deg C (instrument resolution, reading error, rounding error etc):
Boulder, CO 1900-2018. Daily Tmin. Possible trends within +/- 0.5 uncertainty
And for clarity, just possible trend for the same location and period – all within +/-0.5. uncertainty range:
Range of trends within +/- 0.5 uncertainty range
Bob, so long as you have Tmin and Tmax data, I kinda would like to see trends on each separate, rather than as an average. If the Tmin has an uptrend significantly larger than Tmax, that would tend to undercut the urgency of all the Alarmists’ cries for action.