Urban night lighting observations challenge interpretation of land surface temperature observations

by Alan Longhurst

The pattern of warming of surface air temperature recorded by the instrumental data is accepted almost without question by the science community as being the consequence of the progressive and global contamination of the atmosphere by CO2.   But if they were properly inquisitive, it would not take them long see what was wrong with that over-simplification: the evidence is perfectly clear, and simple enough for any person of good will to understand.

In 2006 NASA Goddard published two plots showing that the USA data[1] did not follow the same warming trend as the rest of the world. Rural data numerically dominate the USA archive, while urban data massively dominate almost everywhere else.   Observations began very early in the USA – being introduced by Jefferson in 1776 – and that emphasis had already then been placed on providing assistance to farmers.

Screen Shot 2022-12-17 at 9.30.01 AM

They are consistent with the ‘global warming‘ that so worries us today being an urban affair, caused not by global CO2 pollution of the global atmosphere but by the heat of combustion of petroleum we burn in our vehicles, our homes and where we work – all of which is additive to the radiative consequences of our buildings and impermeable cement and asphalt surfaces. However, towns and cities in fact occupy only a very small fraction of the land surface of our planet, about 0.53% (or 1.25%, if their densely populated suburbs are included) according to a recent computation done with rule-based mapping. But it is in this very small fraction of land surfaces that most of the data in the CRUTEM or GISTEMP archives have been recorded.

Consequently, very few surface air temperature observations have been made in the small villages which, with their farms and grazing lands, are scattered in the otherwise uninhabited grassland. forest, mountain, desert and tundra.  Nor is it widely understood that our presence there has been associated with progressive change since the introduction of steel and steam to plough the grasslands and to cut forests for timber.[2] 

A measure of the brightness or intensity of night lighting, the BI index, was derived by NASA from the work of Mark Imhoff, who calibrated and ranked night lights in seven stable classes – one rural, two peri-urban and four urban.[3]   The BI indes for airport of Toulouse is at 59 and the central district of Cairo is at 167.  Care must be take with apparent anomalies similar to that of Millau which is an active little town of 20,000 people but it has a BI = 0, as does Gourdon which has only 4000.  This is because the MeteoFrance instruments at Millau have been placed on a bare hilltop on the far side of a deep, unbuilt valley adjacent to the town and so they record only the  conditions of the surrounding countryside.

It is not only in major cities that the effects of urbanisation can be detected; this effect can also be detected in data from some very small places that would otherwise be considered rural as at Lerwick, a port in the Orkney Islands with a population of <7000.  Here, the GHCN-M data from KNMI show a warming of about 0.9oC over the period 1978-2018, while during the same period the day/night temperature difference increased by 0.3oC.  Retention of heat at night is characteristic of urban warming.

But Gourdon, a compact little rural village not far from my home in western France has a BI of only 7 for a population of only 3900.  It is situated in farmland that was abandoned 150 years ago when the vines died, and it is now given over to sheep, goats and scrub vegetation.   Little hamlets in this region are now often dark at night and their road signs may warn you that you are entering a ´Starlit village´.

Despite its deep isolation, there is a manned Meteofrance data station in Gourdon which over a 60-year period has recorded a very gradual and small summer warming since mid-20th century, associated with perfectly stable winter conditions.

   Screen Shot 2022-12-17 at 9.39.28 AM                                     

Since buildings and human activity have undoubtedly changed at Gourdon in this long period, perhaps especially by the growth of rural tourism, this effect was probably predictable.  The same is seen in data from other small places such as Lerwick, a port in the Orkney Islands with a population about twice that of Gourdon.  Here, GHCN-M data from KNMI show a warming of about 0.9oC over the period 1978-2018 while during the same period the day/night temperature difference increased by 0.3oC.

The BI values for night lighting are in no way influenced by fact that the thermometric data with which each is associated have later been merged with data from another station to achieve regional homogeneity.   Consequently, it is appropriate to associate them with night-light data in the hope of isolating the effects of local combustion of hydrocarbons in towns and cities, from what we must attribute to solar variation.    The consequences of homogenisation on the surface air temperature data is avoided here by the use of GHCN-M data from the KNMI site – which are as close to the original observations, adjusted only for on-site problems, as is now possible to get.

The urban warming phenomenon has been observed and understood for almost two hundred years.  Meteorologist Luke Howard (quoted by H.H. Lamb) wrote in 1833 concerning his studies of temperature at the Royal Society building in central London and also at Tottenham and Plaistow, then some distance beyond the town:

But the temperature of the city is not to be considered as that of the climate; it partakes too much of an artificial warmth, induced by its structure, by a crowded population, and the consumption of great quantities of fuel in fires: as will appear by what follows….we find London always warmer than the country, the average excess of its temperature being 1.579°F….a considerable portion of heated air is continually poured into the common mass from the chimnies; to which we have to add the heat diffused in all directions, from founderies, breweries, steam engines, and other manufacturing and culinary fire..’ [4]  

To Luke Howard’s list must now be added the consequences of the combustion of hydrocarbon fuels in vehicles, mass transport systems, power plants and industrial enterprises located within the urban perimeter, cement/asphalt surfaces and their relative contributions day and night.[5]

The energy budget of the agglomeration of Toulouse in southern France is probably typical of such places: anthropogenic heat release is of order 100 Wm2 in winter and 25 W m-2 in summer in the city core, and somewhat less in the residential suburbs.  Observations of resulting evolution of surface air temperatures in central Toulouse are compatible with the anticipated effect of the inventory of all heat sources seasonally.  Below the urban canopy layer, a budget for heat production and loss through advection into surrounding rural areas has been computed and it is found that this loss is important under some wind conditions.  In this and many other urbanisations, there is also an important seasonality of heat release by passing road traffic that forms a major component of the heating budget, since national highway systems commonly pass close to major centres of population.[6] 

Larger cities, larger effects: in the core of the city of Tokyo during the 1990s the seasonal heat flux range was 400-1600 W.m-2 and the entire Tokyo coastal plain appears to be contaminated by urban heat generated within the city, especially in summer when warming may extend to 1 km altitude, much higher than the simple nocturnal heat island over large cities.[7]   The long-term evolution of urban climates is well illustrated in Europe where, in the second half of the 20th century when their natural association with regional climate was abruptly replaced by a simple warming trend that took them almost 2oC above the base-line of the previous 250 years.

    Screen Shot 2022-12-17 at 9.45.11 AM

Although, globally, the energy from urban heat is equivalent to only a very small fraction of heat transported in the atmosphere, models suggest that it may be capable of disrupting natural circulation patterns sufficiently to induce distant as well as local effects on the global surface air temperature pattern.  Significant release of this heat into the lower atmosphere is concentrated in three relatively small mid-latitude regions – eastern North America, western Europe and eastern Asia – but the inclusion of this regional injection of heat (as a steady input at 86 model points where it exceeds 0.4W m2) has been tested in the NCAR Community Atmospheric model CAM3. 

Comparison of the control and perturbation runs showed significant regional effects from the release of heat from these three regions at 86 grid points where observations of fossil fuel use suggest that it exceeds 0.4 Wm-2.  In winter at high northern latitudes, very significant temperature changes are induced: according to the authors, ‘there is strong warming up to 1oK in Russia and northern Asia…. the north-eastern US and southern Canada have significant warming, up to 0.8 K in the Canadian Prairies’.

The suggestion that the global surface air temperature data – on which the hypothesis of anthropogenic climate warming hangs – are heavily contaminated by other heat sources is not novel.  The map below shows the locations of 173 stations used by MacKittrick and Michaels for a statistical analysis of the contamination of the global temperature archives by urban heat., using which they rejected the null hypothesis that the spatial pattern of temperature trends is independent of socio-economic effects which was, and still is, the position taken by the IPCC – for which MacKittrick was then a reviewer.[8]

Screen Shot 2022-12-17 at 9.47.05 AM                     

In the present context, this study seemed worth repeating, so a file of 31 clusters of BI indices was gathered from the ‘Get Neighbours’ lists that are shown when accessing GISTEMP data.  These clusters comprise 1200 data files representing 776 towns or cities and 424 rural places – of which 355 are totally dark at night.  They therefore represent a wide range of individual station histories – many longer than 100 years – and are sufficient for the task.   Just 53 of the 540 rural sites listed are in Western Europe, the remainder being located in the vast, night-dark expanses of Asia – where the data based on the arctic island of Novaya Zemyla includes only three with significant night lights,  of which one is the city of Murmansk.

 The cluster centred southeast of Lake Baikal includes two cities (329,000 and 212,000 inhabitants having BIs of only 28 and 13) together with 39 small places – of which 28 are totally dark at night  – while that immediately to the west of Baikal includes 19 such places.   But not all bright locations have large populations, because intensive industrial farms – solar panel energised – can dominate regional night lighting as it does at in some Gulf States: an experimental farm alone here generates a BI of 122, while the 3012 people who live at Shiwaik generate a BI of 181.

The map below indicates the central locations  of 30 clusters in relation to the distribution of native vegetation type. [9]   Screen Shot 2022-12-17 at 9.50.20 AM                         

                                  Central stations of each cluster 

        Place name                              Radius km   BI=0 BI>25  Npop<1K    N       E      

  1   Gourdon, France                                  288       5           1               6         44.7  01.4

  2   Valentia Observatory, S. Ireland    400       14         2              14        51.9  10.2

  3   Santiago Compostella, Spain           406      7          23              2          42.9   06.4

  4   Muenster, Germany                         109      1          7               0          52.4   07.7

  5   Innsbruck, Austria                           107      9           2               4          42.3   11.4

  6   Bursa, Turkey                                  224     12         1                2          40.4   25.1 

  7   El Suez, Egypt                                 532       7       21                0            25.4   32.5

  8   Abadan                                             628        6       17                0         30.4   48.5

  9   Gdov, Russia                                    224      14         5             10          58.7   27.5

10  Saransk. W Russia                            434        9         9                1          54.1   45.2

11  Tobolsk, Russia                                 482         8        7                5          58.1   68.2

12  Lviv, Ukraine                                    293      10        5                2           49.8   23.9     

13  Simferopol, Crimea                           397       14        4                2           44.7   34.4            

14  Tulun , Russia                                    485      19        4               9            54.0   98.0

15  Tatarsk, Russia                                    308      14         1               6           55.2   75.9

16  Krasnojarsk, Russia                            391     13         2               7            56.0   92.7

17  Ostrov Gollomjanny, Russia i             277      38         2            24           79.5   90.6

18  Malye Kamakuki, Russia                     82      30         1            23            72.4   52.7

19  Kokshetay, Kazakstan                          460      15         3              2          53.3   69.4

20  Cardara, Russia                                   212       12         0              1           41.3   68.0

21  Nagov, Russia                                     696      30         0              4          31.4   92,1

22  Selagunly, Russia                                846      26        0              5            66.2  114.0

23  Loksak, Russia                                    493       31         0            11          54.7  130.0

24  Gyzylarbat, Russia                              636       20         5             5          38.9    56.3

25  Ust Tzilma, Pechora Basin                 451        16         1           7           65.4    52.3

26  Cape Kigilyak, Kamchatka               1055        37        0            9          73.3  139.9

27  Dashbalbar, Mongolia                       435       29         1            6           49.5  114.4    

28  Guanghua, China                               465       17         2             ?           32.3  111.7   

29  Youyang, S. Korea                            417       26          0            ?          28.3  108.7

30  Poona, N. India                                 681         4          7            0          18.5   73,8

31  C. India                                             601         1        17            0          23.2   71.3     

32  Mai Sariang, Burma                          57         10          4            1          68.2    97.9

33  Central Japan                                   203          5       13            1          34.4  132.6

 

These data may be used to investigate the supposed warming of Europe and Asia that so worries the public.  In far eastern Russia and neighbouring territories 8 clusters are listed  which include 296 place-names lacking any night-lighting at all, together with just five small towns having night-light indices of only 1.  In such places, it is the natural cycle of climate conditions – modified locally by progressive anthropogenic change in ground cover – that dominates the global pattern of air temperature, and in rural regions there is a rather simple relationship between population size and BI.

Towns and villages occupy only a very small fraction of the continental land surface of our planet, currently about 0.53% – or 1.25% if their densely-populated suburbs are included – according to a recent study using rule-based mapping.  Although it is peripheral to the present discussion, it must be emphasised that conditions in the sparsely-inhabited rural or natural regions are not static at secular scale – everywhere, including in Asia, grasslands and prairies have been grazed or ploughed, and forests clear-cut and replaced with secondary growth.

Consequently, the distribution of population is highly aggregated and associated – as it must be – with regional economic development.  This is illustrated in the images below which show that in western Europe access to the sea is critical, as it is in Japan, while in night-dark Ukraine and Russia it is the zones of temperate broadleaf forest and temperate steppe in which settlement and urban development has been most active.[10]  The arctic tundra belt is very sparsely populated but does includes a few industrialised cities, of which Archangelsk is the largest.

Screen Shot 2022-12-17 at 9.53.00 AM     

Although, globally, the energy from heat of combustion is equivalent to only a very small fraction of the energy transported in the atmosphere, models suggest that it may be capable of disrupting natural circulation patterns sufficiently to induce distant as well as local effects on the global SAT pattern derived from observations.  Significant release of this heat into the lower atmosphere is concentrated in three relatively small mid-latitude regions – eastern North America, western Europe and eastern Asia – but the inclusion of this regional injection of heat (as a steady input at 86 model points where it exceeds 0.4W m2) in the NCAR Community Atmospheric model CAM3 has important but distant regional effects, especially in winter. 

Comparisons of control and perturbation runs show significant regional effects from the release of heat from these three regions at 86 grid points at which observations of fossil fuel use suggest that it exceeds 0.4 Wm-2: specifically, in winter at high northern latitudes, very significant temperature changes are induced: according to the authors, ‘there is strong warming up to 1oK in Russia and northern Asia…. the north-eastern US and southern Canada have significant warming, up to 0.8 K in the Canadian Prairies’.  Especially in northern North America, where the instrumental record is excellent, this effect is readily observed night lighting is highly aggregated and associated – as it must be – with regional economic development.  This is illustrated in the image above which shows that in western Europe access to the sea is critical, as it is in Japan, while in night-dark Ukraine and Russia it is the zones of temperate broadleaf forest and temperate steppe in which settlement and urban development has been most active.[11]

In eastern Asia, 8 clusters include 268 places that are dark at night, together with just 47 having some night-lighting, mostly of intensity <20.  They include only one city (BI = 153).   In such regions, it is the multi-decadal cycle of solar brilliance that dominates the evolution of air temperature, modified by local effects of change in vegetation and ground cover.

But it is really a misuse of the term ‘rural’ to apply it to the small inhabited places scattered across northern Asia, for this implies some similarity with landscapes such as surrounds Gourdon, devoted now or in the past to farming and herding.  But small villages in asiatic Russia have nothing to do with rurality: their houses and streets have simply been set down in natural terrain – in the wildlands, if you will – that is subsequently ignored; there are no crops, gardens or greenhouses, and the activities of the population are not clear.  The wide unpaved streets bear very few motor vehicles – and there is no street lighting.  Many are described as administrative centres and some have a small dirt runway for light aircraft, while a few seem not to be connected to the rest of the world by dirt roads even seasonally,

Here are two small places in northern Siberia with very different seasonal temperature regimes, of which one is clearly well on its way to urbanisation.  Each lies between 65-70oN on the banks of the river Lena.

Screen Shot 2022-12-17 at 9.54.44 AM Zhigansk is a long-settled little town founded in 1632 by Cossacks sent to pacify and tax the region; it is now an administrative centre housing 3500 people., laid out beside the river on a rectangular grid.  Until the Lena freezes, it has no road access to the outside in winter.

        Screen Shot 2022-12-17 at 10.11.08 AM

Kjusjur, just south of the mouth of the Lena in a subarctic environment, was founded in 1924 as the administrative centre for this region, and has a population of 1345; routine meteorological data began to be collected in 1924 and continues today.  About 100 small houses and one larger building are set on unpaved streets beside the stony bank of te river; it has neither runway nor river landing place, but rough tracks leave the settlement to north and south which must be impassable much of the year.[12]

Two motor vehicles can be seen in Kjusjur and a few small boats are pulled up on the beach, while there are about ten motor vehicles in Zhigansk and neither place has any street lighting. Zhigansk has a dirt airstrip with a radar installation that perhaps also houses the meteorological station.   Each has a temperature regime appropriate to its situation, and although it was what I was looking for, I am surprised by the strength of the response to urbanisation at Zhigansk.   I was also expecting that each would respond – at least in very general terms – to solar forcing, and so it does: the cooling of the 1940s and 50s which caused us so much concern in those years about a coming glaciation is clear.

Screen Shot 2022-12-17 at 11.13.49 AM  A compilation of arctic data and proxies took 64oN as the limit of the Arctic region, within which 59 stations were used to analyse the pattern of regional co-variability for SAT anomalies based on PCA techniques.[13]   This demonstrated quasi-periodicity of 50-80 years in ice cover in the Svalbard region: at least eight previous periods of relatively low ice cover can be identified back to about 1200.

Hindcasting climate states is not easy: a recent synthesis of tree-ring data from the Yamal peninsula rashly states that in Siberia the ‘industrial era warming is unprecedented…. elevated summer temperatures above those…for the past seven millennia‘.  However, documents and observations show that this is one generalisation too far.  In summer 1846, as recorded by H.H. Lamb, warming across the arctic extended from Archangel to eastern Siberia, where the captain of a Russian survey ship noted that the River Lena was hard to locate in a vast, flooded landscape and could be followed only by the ‘rushing of the stream’ which ‘rolled trees, moss and large masses of peat’ against his ship, that secured from the flood ‘an elephant’s head’.

The temperature reconstruction below is from annual growth of larches on the Yamal peninisula at the mouth of the Ob.[14]  It testifies that the early decades of the 19th century did indeed include a period of very cold conditions on the arctic coast, while supporting the reality of periods of warmth likely to caused melting of the permafrost of tundra regions.

Screen Shot 2022-12-17 at 10.15.34 AM

 In any case, irruptions of warm Atlantic water into the eastern Arctic – including the present one – are well recorded in the archives of whaling, sealing and the cod fisheries.  The present period of a warm Arctic climate is not novel and there is an abundant record from the cod fisheries in the Barents Sea and beyond, not to speak of the documentation concerning the intermittence of open seas from the sealers and whalers in northern waters.

The surface air temperature data are dominated by observations made in towns and cities so that the secular evolution of the climate is determined not by the gaseous composition of the atmosphere, nor by solar radiation: instead, it is dominated by the consequences of our ever-increasing combustion of fossil hydrocarbons in motor cars, public transit and home heating systems, as well as in the industrial plants and factories  where most of us must work.  To this must be added the daily accumulation of solar heat in the stonework or cement of our buildings facing each other along narrow passages.

One conclusion is unavoidable from this simple exploration of the surface air temperature archive: as used today by the IPCC and the climate change science community the instrumental record is not fit for purpose: it is contaminated by data obtained from that tiny fraction of Earth’s surface where most of us spend our brief span of years indoors.  

Footnotes

[1] Hansen, NASA press release and J. Geophys. Res. 106, D20, 23947-23963.

[2] Ellis, E.C. et al. (2010) Glob. Ecol. Biogeog. 19, 589-606

[3] R.A. Ruedy (pers. comm)- see GISS notice dated Aug 28, 1998, at the Sources website

[4] from H.H. Lamb

[5] see for example, Li, X et al. (2020) Sci. Data 7, 168-177.

[6] Pigeon, G. et al. (2007) Int. J. Climat. 27, 1969-1981

[7] Ichinose, T.K et al. (1999) Atmosph. Envir. 33, 3897-3909, Fujibe, F. (2009) 7th Int. Conf. Urban Clim., Yokohama

[8] McKittrick, R.R. and P.J. Michaels (2004 & 2007) Clim. Res. 26 (2) 159-273 & J.G.R. (27) 265-268

[9] Map is from Gao and O’Neil (2020) NATURE COMMUNICATIONS |11:2302https://doi.org/10.1038/s41467-020-15788, image is from eomages.gf.nasa.go

[10] Map from Gao and O’Neil (2020) NATURE COMMUNICATIONS |11:2302https://doi.org/10.1038/s41467-020-15788, image is from eomages.gf.nasa.gov

 

[11] Ellis, E.C. et al. (date) Global Ecol. Geogr. 19, 589-60, and “Anthropogenic biomes: 10,000 BCE-2025 CE (doi.3390/land9050129v

 

[12] Images from Google Maps software

[13] Overland, J.A.. et al. (2003) J. Clim. pp-pp

19 Polyakov, I.V. et al. J. Clim. 16, 2067-77

 

 

63 responses to “Urban night lighting observations challenge interpretation of land surface temperature observations

  1. Roger Pielke Sr

    I recommend also http://pielkeclimatesci.files.wordpress.com/2013/02/r-371.pdf on this topic

  2. Dr. Spencer recently published articles on the urban heat island effect using Landsat imagery-based diagnoses of increased urbanization over time, see;
    https://www.drroyspencer.com/2022/11/de-urbanization-of-surface-temperatures-with-the-landsat-based-built-up-dataset/
    https://www.drroyspencer.com/2022/11/the-warming-that-happens-in-vegas-stays-in-vegas/
    https://www.drroyspencer.com/2022/11/canadian-summer-urban-heat-island-effects-some-results-in-alberta/

    This also shows that, as Alan Longhurst wrote, “the instrumental record is not fit for purpose: it is contaminated by data obtained from that tiny fraction of Earth’s surface where most of us spend our brief span of years indoors.”

  3. Lower tropospheric satellite temperature does not suffer from urban heat island effect. UAH shows a 0.13°C/decade warming since 1979, or about +0.56°C. Whether that number is meaningful or not is open to to discussion, but that there has been significant warming is not. The crucial question to me is what part of that warming is anthropogenic. We can’t answer that, but to assume an insignificant natural contribution with our poor climate knowledge is a clear mistake.

    • Well stated

    • Using data from Loeb (2021) we can attribute the human component of warming. This analysis of CERES data and attribution after Santer finds 3x more warming the last 20 years from increased absorbed solar radiation (ASR) than from CO2 and all other trace GHG’s combined. Water vapor accounts for a bit more than the trace GHG’s despite changing very little below 300mb (~9km)
      Units below w/m2/decade per Loeb

      ASR .65
      Trace GHG’s .24
      WV .3

      Total 1.19

      We can distribute the effects of WV assuming that the increase is from GHG and solar warming such that trace GHG’s get another .06 bringing their total to .3

      Were all the trace GHG increase human it would be simple to say we are responsible for .357 w/m2/decade, but soil respiration produces 6x more CO2 annually than humans. It is temperature sensitive according to a metric Q10, the increase for a 10C rise in temperature. Q10 is currently modeled at 50 to 100%. Let’s not be crazy and just say soil respiration increased .5% or 3 GtC over the last 20 years from all the warming. That leaves humans with ~3/4 of the CO2 increase or ~.225 w/m2/decade

    • Javier while attempts and experiments have been made to remove UHI effects from various satellite images, there is no robust evidence this has been successful:

  4. UAH satellite data does indeed show .13ºC/decade since 1979, if you plot a straight line trend line, but that seems to be the only, and overly simplistic, view that climate scientists understand.

    A few more years of studying mathematics, logic, and data analysis would help climate “scientists” a great deal.

    If you actually LOOK at the graphs and think a bit more deeply, you immediately begin to realize that a straight line is not AT ALL representative as a good summary of what you see there.

    What you ACTUALLY see, however, does reflect quite accurately and almost entirely many of the well-known and TOTALLY NATURAL changes that have occurred in the climate over the past 43 years.

    Hmmm…

    • Jonathan wrote:
      A few more years of studying mathematics, logic, and data analysis would help climate “scientists” a great deal.

      Please, you should not refer to them as “scientists”, they are just climate people, actual “scientists” are skeptic, they question everything, no, they are not any kind of “scientist”!

  5. And yes, Javier, whether there has been significant warming is most definitely open for discussion. Unless of course, you don’t consider yourself a scientist…

  6. Clearly the data referenced show regional and local variations of surface measured temperature, recognizing urban heat islands. However, there are satellite measured global data sets that support the global averages calculated from averaged surface measurements.

    • If by “support” you mean that 2 = 5, then I suppose so… In the real world, however, 2 does not equal 5 and 10 does not equal 100. Complex concepts…

    • GISS for example reports .18ºC/decade and .18 does not equal .13! In fact, it differs by nearly 50%!!!!!!!

    • Further, you might consider that the .13/decade UAH rate is completely within the one-sigma of Holocene centennial temperature NATURAL variability, which was calculated by IPCC lead author and Nobel Prize winner Philip Lloyd in 2015 to be around 1ºC.

      https://www.academia.edu/19376632/20150423_centennial_variability

      Indeed, we had similar-size, small and insignificant warming trends from 1910 to 1940 that obviously had NOTHING to do with the climate “scientist” much detested and maligned CO2 (a pollutant! haha!) — actually a glorious trace gas that gives life to everything on our beautiful planed, and which is at the lowest level of the last 4 billion years.

    • On further review, I think the first two plots of US and Global Temperature are visually misleading because they are plotted to different scales. Plotting them on the same scale shows that there is little difference in the two data sets.

  7. Stuart Nachman

    The USCRN data based on sites believed to be devoid of the UHI, show no appreciable warming since the program began in 2005.

    • True, maybe, but picking “believed to be” sites instead of using firm criteria always carries the risk of perception of cherry-picking. The ’30 clusters’ in this article, OTOH, would appear to be based on firm criteria (ie, non-cherry-picked) and across a broad area. But it’s still a good idea to look at every possible angle.

    • The USCRN is also completely identical to the full ClimDiv network over their period of overlap, suggesting that urbanization is not biasing the full network in the slightest.

  8. Having identified the ’30 clusters’, how about comparing their temperatures over time with other or ‘global’ temperatures. I feel that the article built up interest and then missed its punch line. Or did I miss something?

  9. This was the conclusion:
    One conclusion is unavoidable from this simple exploration of the surface air temperature archive: as used today by the IPCC and the climate change science community the instrumental record is not fit for purpose: it is contaminated by data obtained from that tiny fraction of Earth’s surface where most of us spend our brief span of years indoors.

    Not a bad conclusion but it should not matter.
    The current warm period is still the coldest warm period in the most recent ten thousand years according to Greenland ice core records. We just came out of the little ice age, even including the warmest heat island data, we are well inside the bounds of the last ten thousand years and colder than most of it. There is nothing alarming in the data but they took over the media and the universities and the even NASA, their Climate webpage has nothing on it about any natural climate cycles, the whole page is about CO2, one added molecule to ten thousand, the whole NASA Climate Webpage is all, a whole bunch of ALL ABOUT NEARLY NOTHING!

    ONE DIVIDED BY TEN THOUSAND IS 0.0001

    I worked for NASA for 44 years, Gemini, Apollo, Shuttle, Space Station, all the years and much of my pride in NASA accomplishments become smeared by Climate Rubbish. NASA can’t find even one natural climate factor worth discussing. Water in all of its changing states is abundant. Ice Ages were times that ice spread over large areas causes the climate to be colder from the ice reflecting and ice thawing, no mention of Water or Ice.

    It actually makes my stomach hurt to think about the evil.

    • One of my pet peeves is the argument that because the increase in CO2 is only one in 10,000 atoms so it can’t possibly be of significance. Here is a potential experiment which I hope you will treat as a thought experiment not a real experiment. Dissolve 100 mg of inorganic arsenic in a liter of water and drink it. That’s a lethal dose for many people. If you want to argue that some people could survive that dosage of arsenic, repeat with fentanyl. A lethal dose is 2 mg which is 50 times smaller than one in 10,000.

      Of course, a scientist would point out that the lethal dosage of arsenic or fentanyl has nothing to do with how much CO2 it takes to contribute to warming. I totally agree. My bottom line point is that simply asserting the increase in CO2 is the same as an additional one in 10,000 atoms is a fact, but not a conclusion about the impact on warming. You wouldn’t make this argument with respect to arsenic or fentanyl, so you shouldn’t make it with respect to CO2. There may well be good reasons for questioning the contribution of a small increase in CO2 to warming, but the argument that the increase is only one in 10,000 atoms is not one of the good arguments.

      • “One of my pet peeves is the argument that because the increase in CO2 is only one in 10,000 atoms so it can’t possibly be of significance. Here is a potential experiment which I hope you will treat as a thought experiment not a real experiment. Dissolve 100 mg of inorganic arsenic in a liter of water and drink it. That’s a lethal dose for many people.”

        There is 400 ppm CO2 in Earth’s atmosphere already. It makes 1 for 2,500 or 4 in 10,000.

        What will happen when it is 5 in 10,000?

        When removing 5 out of 10,000 there are still 10,000
        Actually nothing happens.

        https://www.cristos-vournas.com

      • Geoff Sherrington

        Stephen,
        Re how much CO2 to do the work.
        One molecule is not enough. It would have to absorb/emit prodigious energy.
        There is a limit to how much energy a molecule of CO2 can accept. Try to work out what that energy is; and how many CO2 molecules have to be present in the atmosphere before their combined energetics are enough to be measured.
        I have never seen an estimate of this minimum atmospheric CO2 concentration. I have seen many bits of guesswork and arguments over a wide range of quality.
        You have to discount those circular reasoning arguments that use climate sensitivity estimates to derive CO2 concentrations that are “significant”. For a start, the CO2 effect cannot yet be separated from natural effects that can be of similar magnitude.
        Geoff S

      • Stephen Philbrick

        Christos
        re:
        “There is 400 ppm CO2 in Earth’s atmosphere already. It makes 1 for 2,500 or 4 in 10,000.”

        I understood that. The reference to one in 10,000 was in the post I responded to. The presumption being that when the concentration of CO2 was 300 PPM everything was hunky-dory, but some are concerned about the increase to 400 PPM with the difference being 100 PPM or one in 10,000

  10. Reminds me of Steve McIntyre and YAD06 — the Most Important Tree in the World. it’s always a good idea to look at the data in detail.

    https://climateaudit.org/2009/09/30/yamal-the-forest-and-the-trees/

  11. I was hoping to see summary graphs similar to the first two graphs shown in this blog — temperature history in the US, globally, and other geographic regions with the urban location (based on BI levels) temperature data removed. Does someone have this?

  12. Thanks, Alan.

  13. Pingback: Urban night lighting observations challenge interpretation of land surface temperature observations - Climate- Science.press

  14. Geoff Sherrington

    Alan,
    A decade ago I did a similar study to yours, for Australia. We have a land area about the same as the USA48, but a present population of only 26 million. Our Bureau of Meteorology curates or has curated about 1,200 stations of varying quality and longevity, with problems arising from poor metadata and frequent changes to conditions that might affect temperatures. The longest records start about the 1860s.
    Australia is is good test bed to examine the effect of the Hand of Man on near-surface land temperatures.
    Here is my analysis from 2011, updated in 2018.
    http://www.geoffstuff.com/pristine_44_2018.xls
    There are three main conclusions.
    1. The more “pristine” a station, the lower the data quality is likely to be, making some stations next to useless. See essays about uncertainty on WUWT, all three parts, Aug-Oct 2022.
    https://wattsupwiththat.com/2022/10/14/uncertainty-of-measurement-of-routine-temperatures-part-iii/
    2. This type of analysis is quite vulnerable to the choice of start and end dates for time series. My analysis was for years 1972 to 2006 incl. If I now update a station to 2021, I get quite different conclusions.
    3. The noise levels in the data are too large to allow confident conclusions. For a trivial but telling example, the bulk temperature data show correlations with their World Meteoroplogical Organisation numbers.
    If you wish to use this information, please do so without any constraints from me.
    Thank you for your article. Geoff S

    • Geoff Sherrington

      Alan,
      The link to the Excel file appears broken
      Please use this:
      http://www.geoffstuff.com/pristine.xlsx
      When I say that my analysis is similar to yours, mine does not include “lights”. The lights numbers should be available somewhere in the general system, but I have not looked for them because I do not have much confidence in their ability to advance understanding.
      Geoff S

  15. Speaking of, ‘control and perturbation,’ locating official government thermometers at French airports where winter asphalt surfaces are continually swept of snow, resulting in winter average ‘winter warming’ temperatures (demonstrably greater than the surrounding countryside) compared to years ago, cannot be an unconscious corruption of reality.

    • Please tell us more about the people behind these “official government thermometers” [sic]. How did “they” carry out this cunning plan all together, and since when?

      By the way, you do realize there is no lasting snowpack in France, except in high altitude mountain areas (where there is no airport), and that snow on the ground is generally quickly melting, don’t you?

      Moreover, logically, the alleged warming bias should have been greater years ago than nowadays, since there are fewer and fewer snow days in France since the 60s at least. So, that would introduce a cooling bias in the temperature anomaly. Care to explain this point as well ?

      • TarmacGate — There has been no global warming in France over the last 70 years except during the winter, at French airports, where official thermometers are located and also where and when the snow is continually cleared so jets can take off. The same corruption has been discovered in Alaska and Russia where official thermometers were located. The motives underlying this method of positively skewing the data also explains why the temperature record of the White Mountains (where there has been no global warming for 100 years) and the temperatures at the coldest places on Earth are all just simply ignored. New Zealand has no temperature record because the official temperature was arrived at through a purposeful manipulation of the raw data without documenting the slightest justification for any of the adjustments made and then simply destroying the raw data altogether. The raw data for the temperatures at an official station in the Antarctic was corrupted by simply removing minus signs from negative numbers, introducing a warming bias where no warming exists. And, we now know there has been no global warming on Earth over the last 10,000 years.

      • So not a real answer but another volley of wild allegations.

        What was I even expecting ?

  16. Pingback: Urban Night Lighting Observations Demonstrate The Land Surface Temperature Dataset is ‘not fit for purpose’ – Watts Up With That?

  17. Pingback: Urban Night Lighting Observations Demonstrate The Land Surface Temperature Dataset is ‘not fit for purpose’ – Watts Up With That? - Lead Right News

  18. Pingback: Nachtbeleuchtungs-Beobachtungen in Städten stellen eine Herausforderung für die Interpretation von Messungen der Temperatur auf dem Festland dar | EIKE - Europäisches Institut für Klima & Energie

  19. It has been pretty obvious for quite a while to any and all actual scientists who have looked at the actual mathematics and data, that the urban heat island effect (UHI or UHE) MASSIVELY contaminates the land-thermometer-based data sets, i.e. all the data that the climate (non) scientists constantly refer to ad nauseam. (Indeed, the most basic principles of physics — something that climate (non) scientists don’t study any more — by themselves demonstrate that the very notion of a thermometer-based “surface temperature” is completely ridiculous, but I digress.)

    There is a very good and convincing recent paper by Nicola Scafetta (Detection of non‐climatic biases in land surface temperature records by comparing climatic data and their model simulations. Clim Dyn 56, 2959–2982 (2021). https://doi.org/10.1007/s00382-021-05626-x) that determines the ENTIRE difference between UAH and all of the activist-run-and-regularly-manipulated-with-secret-and-largely-fake-adjustment land-based-thermometer datasets (GISS, Berkeley, HadCRUT …) is due to UHE.

    So as a first step, any and all serious scientists should forever forswear further reference to the fictitious, activist-run-and-manipulated so-called “data” sets. (Interesting, isn’t it, how ALL of the secret “corrections” to these “data” sets make the past cooler and the present warmer!?!?)

    Therefore, going forward as a starting point, can we at least all agree that anyone who references GISS, Berkeley, HadCRUT, … as actual data sources is clearly NOT a scientist?

  20. Dietrich Hoecht

    here is a survey of US land based weather stations that give us the temperature profiles, showing nearly all are compromised from heat ‘poisoning’. https://wattsupwiththat.com/2022/07/27/new-surface-stations-report-released-its-worse-than-we-thought/
    I hope that this link still works.

  21. Geoff Sherrington

    Further to Australia as a good test bed for temperature measurements avoiding UHI and so on, the UAH satellite temperature anomalies in the lower troposphere aver Australia show a slight cooling trend now lasting 10 years and 5 months to the present.
    http://www.geoffsuff.com/uahdec2022.jpg
    The corresponding pause for the whole globe by this Monckton method lasts 8 years and 1 month. Clearly, there are influences at work that reduce or negate the alleged CO2 warming of the atmosphere. UHI is one identified effect that fits the bill rather neatly.
    Sadly, satellite-derived temperatures are not mentioned in 2 recent major Australian climate reports. They are the CSIRO/BOM State of the Climate report 2022
    https://www.csiro.au/en/research/environmental-impacts/climate-change/state-of-the-climate
    and a major, but now hard-to-find fiction “The Risks to Australia from a 3deg C Warming World” from our Australian Academy of Sciences, March 2021. Its peer-review authors were each other, so it might not have made it into the global scene – but it sure was publicised by local media at the time.
    Today, Roger Pielke emailed about United Nations Secretary-General António Guterres saying about recent disasters “There is nothing natural about the new scale of these disasters. They are the price of humanity’s fossil fuel addiction. The number of weather, climate and water-related disasters has increased by a factor of five over the past 50 years.” This take is clearly and dramatically at odds with most reported scientific observation and measurement.
    ………………………….
    Some hard work needs to be done now to stop fiction-as-science from routing the customary and successful Scientific Method. Therefore, thanks again to author Alan Longhurst for this article.
    Geoff S

  22. Geoff Sherrington

    Someone is playing with my links.
    Please use
    http://www.geoffstuff.com/uahdec2022.jpg
    Geoff S

    • @Geoff Sherrington, to clarify, here is part of what Roger Pielke Jr. said to Guterres,

      “As I and others have documented, Guterres’s claim of a 500% increase in disasters is pure misinformation. You will never find a more obviously egregious, wrong claim in public discussions from a more important institution. [emphasis, links added]

      Making matters worse, the false notion of a massive increase in disasters is legitimized by none other than the World Meteorological Organization, one of the founding bodies of the Intergovernmental Panel on Climate Change.”

  23. Today, Roger Pielke emailed about United Nations Secretary-General António Guterres saying about recent disasters “There is nothing natural about the new scale of these disasters. They are the price of humanity’s fossil fuel addiction. The number of weather, climate and water-related disasters has increased by a factor of five over the past 50 years.”

    You wrote that and did not include any link or proof.
    Yes now we have a factor of orders of magnitude increase on reporting every kind of disasters but actual data, you need to present the actual data, not likely from Roger Pielke, if Roger Pielke reported about whatever the United Nations Secretary-General António Guterres is saying about recent disasters, that is just pointing out the lies not an agreement!

  24. very simply nightlights are not fit to define urban, nor are they an adequate proxy for the known causes of UHI. this has been demonstrated countless times.

    • Do you have the references to studies that show night lights do not correlate or define urban areas?

    • Results: From far above the Earth, a satellite’s view of nighttime lights reveals the globe’s most populous urban areas. A new method maps urban areas using the night sky light intensity measured by those satellites; the method was developed by researchers at Pacific Northwest National Laboratory working at the Joint Global Change Research Institute. They collaborated with scientists from the National Oceanic and Atmospheric Administration (NOAA) and The Ohio State University (OSU) to reduce the over- and under-estimations associated with previous techniques when mapping a large area. The new method also shows the potential to map the extent of urban areas with a global perspective, and the changes over time, using existing data in a cost-efficient way.

      https://www.pnnl.gov/science/highlights/highlight.asp?id=3737

    • A strong relationship between night-time light (NTL) data and the areal extent of urbanized regions has been observed frequently. As urban regions have an important vertical dimension, it is hypothesized that the strength of the relationship with NTL can be increased by consideration of the volume rather than simply the area of urbanized land. Relationships between NTL and the area and volume of urbanized land were determined for a set of towns and cities in the UK, the conterminous states of the USA and countries of the European Union. Strong relationships between NTL and the area urbanized were observed, with correlation coefficients ranging from 0.9282 to 0.9446. Higher correlation coefficients were observed for the relationship between NTL and urban building volume, ranging from 0.9548 to 0.9604; The difference in the correlations obtained with volume and with area was statistically significant at the 95% level of confidence. Studies using NTL data may be strengthened by consideration of the volume rather than just area of urbanized land.

      https://www.researchgate.net/publication/336851451_Night-time_lights_are_more_strongly_related_to_urban_building_volume_than_to_urban_area

    • It’s the LED Paradox; They don’t save energy because we start putting them everywhere and run them 24/7. Useful map but not a good fit for this purpose.

      It might be more enlightening to merge all the geolocated surface energy radiation sources into one giant database. The data is there but there may be too many overlapping government/corporate conflicts.

    • Hi Steven, I know the UHI is a long interest of yours, and I am curious if your view has evolved any since 2016 when you wrote this:
      “Since we see UHI in individual records it seems OBVIOUS that the global record should show some sign of it.. after all there are plenty of urban sites in the total average.

      But when we use the same method, that found the signal in individual cases, and apply it to global data, the signal
      gets attenuated.. to the vanishing point. [Peterson 2003]

      To me it is still a mystery of sorts. I was relieved when I found a small signal ( .03C/decade) in the US. when I unleashed that same method on the globe….. POOF that small effect disappeared.” -SM

      Did you look at Dt. Roy Spencer’s analysis of Canadian UHI? He found it accounted for 20% of the CRUTemp5 warming since 1978.
      https://www.drroyspencer.com/2022/11/canadian-summer-urban-heat-island-effects-some-results-in-alberta/

  25. Whenever I have researched where weather stations are for record highs in the UK they have typically been at airfields and although they are on a grassed area are still near to the runway. As a separate point Lerwick is on Shetland and not the Orkneys and I am not certain if it is a good example because the temperature is dominated by the ocean temperatures. Day and night temperatures do not fluctuate compared to areas that are not surrounded by the ocean.

  26. I borrowed this graphic from Tony Heller. Until someone can explain why CO2 can increase 25% of more and cause no warming at all at many locations across the globe, then 100% of climate studies are suspect. Start with the basics. Why does CO2 cause warming in some locations and not others? Until you can explain that simple question, all these studies are nonsense, and certainly can’t explain this observation.
    https://data.remss.com/msu/graphics/TLT/plots/RSS_TS_channel_TLT_Southern%20Polar_Land_and_Sea_v03_3.png

  27. 1, CO2 is 400 parts per million, man is claimed to be responsible for 100 ppm since the start of the industrial age. That means man produced 1 CO2 molecule for every 10,000 molecules in the atmosphere. Does it seem plausible that vibrating 1 out of every 10,000 molecules with the energy consistent with 15-micron LWIR can materially alter the thermal energy of the other 9,999?

    2. CO2 and H2O easily impede 100% of outgoing 15 LWIR at an altitude very close to the surface. Increasing CO2 does nothing more than slightly lower the altitude where 100% saturation is reached. How does that possibly alter the climate and weather above that layer? Nothing changes, the saturation level simply gets lowered. You can’t “trap” more than 100% of the available energy.

    3. The below image shows no warming for a large part of the earth with an increase of CO2 by about 25%. How can CO2 warm some areas of the earth and not others? Do the laws of physics cease to exist in certain parts of the globe? There are also many many many more locations that show no warming all over the globe.
    https://i0.wp.com/wattsupwiththat.com/wp-content/uploads/2022/12/RSS_TS_channel_TLT_Southern-Polar_Land_and_Sea_v03_3-1671889468.959.png?fit=440%2C240&ssl=1

  28. Jonathan Cohler

  29. Pingback: Die Regenmacher vom Deutschen Wetterdienst oder, wie Temperaturen auf raffinierte Weise warm gemacht werden. Teil 2 | EIKE - Europäisches Institut für Klima & Energie

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