3% of Earth’s landmass is now urbanized

This study, from 2005, is not one I’ve covered here before, but I thought it was relevant to have a look at as a logical followup to the recent announcement from NASA at AGU that satellites have identified strong UHI signatures in cities. The vast majority of the world’s surface weather stations used to monitor climate are in urban areas, many in the GHCN for example are at urban airports. h/t to Joe and Pete. – Anthony

From Columbia University Earth Institute: The Growing Urbanization of the World
GRUMP mapping project finds urban areas increasing in surprising ways

mapNew data collection from CIESIN’s Global Rural Urban Mapping Project shows that as much as three percent of the Earth’s land area has already been urbanized, which is double previous estimates. The map above illustrates the extent of some urban areas, with callouts overlayed by ecosystem. click here for larger image 

The majority of the world’s population will soon live in urban rather than rural areas. Adding a spatial dimension to population estimates, a new study finds that as much as three percent of the Earth’s land area has already been urbanized, which is double previous estimates.

This new data collection, known as the Global Rural Urban Mapping Project, or GRUMP, has provided the basis for a number of important insights not previously known. This project is led by the Center for International Earth Science Information Network (CIESIN), part of the Earth Institute.

The following are a few key insights from GRUMP:

  • GRUMP shows that 20% of the world’s urban population live in settlements that have populations below 500,000. This is an important finding considering that the UN Population Division only reports on urban settlements of 500,000 inhabitants or more.
  • GRUMP data indicate that roughly 3% of the Earth’s land surface is occupied by urban areas, an increase of at least 50% over previous estimates that urban areas occupied 1-2% of the Earth’s total land area.
  • Coastal environments have much higher concentrations of urban land area (10%) and urban populations (65%) than other ecosystems.
  • Far fewer Asian and African urban residents live in coastal and cultivated areas than residents of the Americas, Europe and Oceania, however, population densities in coastal cities of Asia and Africa are much greater than those on other continents.
  • GRUMP shows that approximately 7% of the world’s population now resides in the largest mega-cities, whereas experts had previously estimated this number to be around 4%.
  • GRUMP has identified about 75,000 distinct settlements worldwide, but only 24,000 urban areas—the result of many agglomerated urban settlements.
mapGRUMP has identified about 75,000 distinct settlements worldwide, but only 24,000 urban areas—the result of many agglomerated urban settlements. The above populations map highlights clusters of urban areas around the world. click here for a larger interactive version of this map 

“The GRUMP datasets will allow us to rethink trends in urbanization and the relationship between population, ecosystems and land use,” explained Dr. Deborah Balk, a demographer at CIESIN and the principal investigator of GRUMP. “GRUMP shows us that the urban experience is not uniform, that city-size matters, and city distribution matters. Coastal areas are more urban than other ecosystems, for example, and even rural populations in coastal ecosystems are much denser than in other rural areas.”

This study has resulted in the construction of a suite of products constituting the first detailed and systematic data sets on urban population distribution and the extents of human settlements across the globe.

Although population census and satellite data have been available for some time, until now minimal effort had been made to combine these two kinds of information to capture the geographic boundaries of human settlements.

The GRUMP data collection consists of three individual databases that build upon population datasets mostly from national statistical offices, satellite data and other representations of settlements. GRUMP Human Settlements is a global database of cities and towns of 1,000 persons or more, each represented as a point, and includes information on population sizes, longitude and latitude coordinates, and data sources. Populations were estimated for 1990, 1995 and 2000. The GRUMP Urban ExtentMask is the first systematic global-scale attempt to portray the boundaries of urban areas with defined populations of 5,000 and larger. The GRUMP Population Grid represents the distribution of human population across the globe, accounting for urban population concentration more precisely than previous efforts. It allows for inferences about urban versus rural populations, and cities of different sizes, when used in combination with the Urban Extent Mask.

In contrast, prior data sets such as those from the United Nations or the Digital Chart of the World indicated either the population size or extent of urban areas, but not both.

“For us, knowing more about the number and distribution of rural populations is critical,” said Stanley Wood, head of the Spatial Analysis Research Group at the International Food Policy Research Institute (IFPRI) that supported and collaborated on GRUMP. “Past spatial population datasets have confounded urban and rural populations, but the better we can distinguish patterns of rural population, farming and use of natural resources, the better placed we are to address the major challenges of rural development and poverty alleviation. GRUMP is an important step in the right direction.”

GRUMP delineates urban boundaries across the planet ranging in size from 1 km2 to the largest of urban extents, Tokyo, which includes more than 500 connected settlements and is the largest urbanized area in the world at 30,000 km2. “The night-time lights satellite, the [primary technology used to detect] urban extents, tends to overestimate the geographic size of highly-electrified cities, but for those cities, we have much more detailed sub-city population data to supplement the extent information,” said Balk. GRUMP has shown that in the year 2000, there were 24,000 urban areas across the globe with 5,000 residents or more. “We know that this is an undercount, because the poorest countries have urban areas that were either hard to detect with the satellite or have weak census-taking. This method is novel and a huge improvement over previous databases. It’s not perfect, but it’s an important achievement,” Balk said.

“Eventually, GRUMP data should revolutionize the way population figures are debated and discussed,” said Dr. Gordon McGranahan, Director of the Human Settlements Programme at the International Institute for Environment and Development.  “The GRUMP presentation of data, particularly if combined with population estimates by location, is so much more amenable to up- and down-scaling and local verification than conventional tables.”

GRUMP data took four years to compile. It drew on years of investment from the Gridded Population of the World (GPW) project in which population counts are converted from irregularly and administratively defined census units to a uniform latitude-longitude grid.

The GRUMP datasets, as well as the newest release (version 3) of GPW, may be accessed through the NASA Socioeconomic Data and Applications Center (SEDAC), operated by CIESIN, at http://beta.sedac.ciesin.columbia.edu/gpw/

GRUMP and GPW datasets and map collections are distributed free of charge.

GRUMP is a collaborative project with partners from IFPRI, the World Bank and the International Center for Tropical Agriculture. Primary financial support was provided by the US National Aeronautics and Space Administration, IFPRI, and the World Conservation Monitoring Center for the Millennium Ecosystem Assessment (www.maweb.org).

The Center for International Earth Science Information Network (CIESIN), a member of the Earth Institute at Columbia University, works at the intersection of the social, natural, and information sciences. Scientists at CIESIN specialize in online data and information management, spatial data integration and training, and interdisciplinary research related to human interactions in the environment. CIESIN researchers seek to provide data that informs scientific, public and private decision-makers worldwide. For more information, visit www.earth.columbia.edu

The Earth Institute at Columbia University is the world’s leading academic center for the integrated study of Earth, its environment and society. The Earth Institute builds upon excellence in the core disciplines — earth sciences, biological sciences, engineering sciences, social sciences and health sciences — and stresses cross-disciplinary approaches to complex problems. Through research, training and global partnerships, it mobilizes science and technology to advance sustainable development, while placing special emphasis on the needs of the world’s poor. For more information, visit www.earth.columbia.edu.

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55 thoughts on “3% of Earth’s landmass is now urbanized

  1. What is the density trigger to be classified as “urban”?

    I.e. how many people per acre?

    The state I live in has some 501(c) 3s that make much tax-exempt hay on “how much land is lost to development” each year, without taking density v. acreage into account (and of course not, because the scary numbers would suffer).

    For instance, let’s say you have zoning of one unit per 40 acres (and we do in our county). Let’s say someone sold 200 acres for residential development, and it was developed under our local zoning laws in a clustered fashion, with more than half of the land left undisturbed after drainfields, power easements, setbacks from well, setbacks from natural waterways and any connected wetlands, and access roads, and that land was then placed in a permanent conservation easement.

    You would have a total of five (5. FIVE.) homes on 200 mostly-preserved acres, yet for the purposes of advocacy literature, you could technically-truthfully say that “another 200 acres was lost to development”, because under law that land had now been “developed” to the limit.

    Our local government staff has begun calling suburban development density of 3-4 units/acre “urban development”. The tendency seems to be to eliminate the suburban (on many levels. Thanks, UN!), even from the very lexicon.

  2. The GRUMP dataset is full of holes. Last I checked Riyadh, Saudi Arabia evaluated as rural.
    On the other side of the coin uninhabited parts of the Cascade Mountain range evaluate as urban.

    On the Riyadh problem the Saudi’s don’t keep official population statistics at the city level they keep statistics at the administrative district level, the boundaries of the administrative districts include huge amounts of ‘unihabited dessert’.

    On the Cascade mountain problem, in the Greater Seattle Area we have city population numbers and then population numbers for the ‘unincorporated’ parts of counties. So a large number of people in King County Washington live in ‘unincorporated king county’ in relatively high density suburbs. The suburbs are crammed in at the base of the Cascades but the county boundary extends quite a distance into the cascades which is national park and uninhabited.

    Grump like so many other ‘data products’ suffers from the ‘tyranny of averages’.

  3. Columbia offers a PhD in Sustainable Development, and their web home page is strewn with ecobabble, so one has to suspect that the impact of development is maximized in their studies.

    But it’s clear that sooner or later the planet will get to Trantor level population density.

  4. I’ve read recently that Detroit is working very hard to De-Urbanize, and is planning to convert former housing subdivisions back into farmland.

    or failing that, just back to wilderness.

  5. How much of that urban area actually does things that make for UHI (lots of dark streets and roofs and windblocks) and how much is dirt streets and single story grass huts which aren’t going to cause a UHI?

  6. 75000 settlements? That’s WAAAAAAAAAAAAAAY low.

    Here’s a website that collects historical records of post offices. So far he has 187,000 listings for the US only. Many of those have disappeared or lost their post office, but it’s a fair bet that most would still show as a “settlement” or a crossroads.

  7. Keep in mind that it’s 3% of the LANDMASS, which is roughly one-fourth of the earth’s surface. Since we can see our changes to the environment, we assume our impacts are great. Yet the sun impacts 50% of the earth’s surface every second of every day, but is minimized because its changes are minor. That’s like preferring 50% of a million US dollars ($500,000) over one-tenth of 1% of a billion ($1,000,000). And I’m guessing the sun’s impact is even more profound than that.

  8. Anthony: Is there any way to calculate how many temperature stations are in urban areas? If a high percentage of stations are in urban settings, it would be safe to assume that a high percentage of warming is actually UHI.

    (latitude: which is why 3% could be such a significant amount, especially if its much larger than thought.)

  9. Three percent of the land mass is now urbanized

    Seems to me that urban heat island effect is a significant component of global warming. So is deforestation. So is a lot of things besides burning fossil fuel.

  10. When your “burning fossil fuels” blinkers are welded firmly to your head, it’s very difficult to look sideways, and appreciate that there are far more likely criteria around you, than the dreaded, deadly, man-made carbon dioxide…

  11. On the need to correct reported temperatures.

    The reason why temperatures have to be corrected for UHI is because the percentage of urbanized land is on the rise and cities are over represented in the record(more than 3% of stations are in cities).

    It is said that some plants like corn could have a cooling effect. But if the amount of corn is on the rise and corn field are under represented in the record, the total effect would be a warming bias. That’s because the cooling effect of corn would be under represented.

  12. latitude says:
    December 23, 2010 at 6:29 am
    “only 3%……………………..which means that 97% isn’t”

    That might be right but one can easily see the potential for a warming bias in the kand instrument record due to UHI if say 80% of the stations are located within that 3%. The problem is further compounded since many stations are truly urban but yet classifiec as rural.

    If the figure of 3% for urbanisation is correct then land temperature data should be based upon 3% urban station data and 97% rural station data.

    Further whilst urbanisation may account for only 3% of land use, man’s influence spreads much wider since man is farming rural land and mining, deforestation etc is affecting rural land.

  13. Obviously the actual space occupied by humans is minimal. It’s the space required to grow and raise our food that’s the problem.

    Conceivably, if power was really really cheap and plentiful, say modular nuclear plants the size of phone booths, we could build multi storey farms right in the cities and towns.

    No need for long distance transport, no need for long term refigeration etc etc

    Level 5 – tomatoes. Level 7 – green beans lol

  14. The population of this planet would fit inside the borders of Russia with lots and lots of room to spare. But I digress lets place the hippies in the northern siberia anyways just for kicks, what with they think it so warm and all.

  15. Some years ago names were being made up for the large urban areas that were beginning to connect to each other.
    The US northeast coast was given the name BoYorkTon for Boston, New York and Washington DC.

  16. My idea of rural is a house maybe a mile away, and another house at least another mile away. Anything closer than that and you have a community that, thanks to modern technology, is an urban heat island. In a word, urbanized. My ranch house is in a little urban community once called Evans. The town is no longer but there are enough houses left that we have either a road between us or a little pasture. The next town is a mile away. My grandparents considered themselves to be living in a once bustling now quiet town, quaint as it was.

  17. Perhaps this will be the next con?

    They’ll go from urban heat bias to “urban heat forcing” – add a few positive feedbacks and let a supercomputer model it into some grade B propaganda for the kids.

    After all, with this estimate showing twice the urbanization then it is worse than we thought!

  18. Urbanisation is a considerable source of heat not just because of the thermal properties of the materials used but also because they are areas that are well drained. Many urban areas have a ‘reach’ beyond their political or physical boundaries. For example Los Angeles consumes enough water to significantly lower the level of Owens Lake and prevent the Colorado from reaching the sea. This means there will be less moisture in the atmosphere in these areas increasing the likelihood of localised warming. So what affect would there be on near surface atmospheric temperatures if groundwater were lowered by several meters or more? I would have thought that temperatures would be higher as less evaporation would take place. So what is happening to ground water across large continents like North America, India, Africa and China?
    Regardless of whether it is 1%, 2% or 3% urbanisation is not distributed evenly over the surface of the Earth. As can be seen urbanisation can be concentrated so that for a given area the coverage may be towards 100%.
    I sense there are those who think that this is yet another eco subject with an agenda to blame humans. Well that’s a shame if that is the case as it means discussion around any environmentally related subjects has become so poisoned to make it almost impossible. I don’t really care whether there is an agenda behind this or not, because my ‘real world’ experience of urbanisation has taught me that there is an effect and it tends to be warmer temperatures and earlier springs and later autumns (unless it’s a north wind).
    I consider myself a sceptic of AGW but not to the point where my scepticism is yet another religion. If I drive my car I take into account whether the tyres have enough air, whether I have enough fuel, whether the engine has enough oil and water, etc. etc. I don’t do this for philosophical or religious or even emotional reasons. I do it for practical reasons because I ‘know’ what will happen if I don’t. In the same vane it doesn’t make sense for me to take care quantifying my immediate world and then adopt a position of deliberate indifference to the world at large because I assume it to be too large to be affected by me.
    This article is a valuable contribution to quantifying the affect urbanisation has on our environment. It does not mean that we should hate ourselves or that it’s all our fault, even if some imply that, but it is information in the same way as the fuel gauge on my car. Urbanisation should be understood so that if required solutions can be applied to it’s consequences.
    Perhaps urbanisation has no affect on the collective global climates but this should not be an assumption. As a minimum there is a local affect that may need management.

  19. The size of Tokyo metropolitan area is staggering 30,000km2, that is 150km x 200km. Population approaching 40 million. Will we see a metropolis with population of 100 million during this century?

  20. Les Johnson says:
    December 23, 2010 at 7:54 am
    Anthony: Is there any way to calculate how many temperature stations are in urban areas? If a high percentage of stations are in urban settings, it would be safe to assume that a high percentage of warming is actually UHI.

    Yes my thoughts exactly. Any idea Anthony? My guess would be greater than 90% of the so called urban areas have the global net stations in them. A completely unrepresentative sampling. Especially when you consider that land surface makes up only about 29% of the earth’s surface. Forests and woodlands make up about 32%. Permanent pastures about 26%. Deserts, mountains, and other about 30%

    Bernie

  21. Les Johnson says:
    December 23, 2010 at 7:54 am
    “Anthony: Is there any way to calculate how many temperature stations are in urban areas? If a high percentage of stations are in urban settings, it would be safe to assume that a high percentage of warming is actually UHI”

    Same question I was going to ask. Anyone know the answer? I would add that non-urban areas of high population density must also be considered. Many non-urban areas in northern OH, for instance, where I grew up, are now very densly populated with what were once farms having become all housing developments which actually connect the small towns to one and other and to the larger cities. Heat generated by such populations will effect the temperature even though these areas may still be considered “non-urban”. Not to mention all the pavement to absorb and hold heat and rooftops either absorbing or reflecting depending upon dark or light color and sunshine or clouds. Call it a theory but I believe temperature measurements are greatly influenced, upward, by such factors. And it’s still getting colder.

  22. GRUMP data is at an alpha stage at this point.

    I have already used GRUMP urban extent to classify every station in GHCN. The GRUMP grid is basically a 1km ( 30 arc second) grid, so the accuracy depends upon have good coordinates for the station.

    As a metric of urbanity GRUMP is pretty good. There is also a population density product. If you combine GRUMP, and GPW and Nightlights, and Impervious surfaces data you can select a fairly large number of stations to define a rural average. Maybe I’ll do that for folks after the holiday break.

    You can see a map of Grump Rural Stations Here:

    All stations with Grump Urban set to Rural and less than 1% impervious surface.

    http://www.google.com/fusiontables/embedviz?viz=MAP&q=select+col0%2C+col1%2C+col2%2C+col3%2C+col4%2C+col5%2C+col6%2C+col7%2C+col8%2C+col9%2C+col10%2C+col11%2C+col12%2C+col13%2C+col14%2C+col15%2C+col16%2C+col17%2C+col18%2C+col19%2C+col20%2C+col21%2C+col22%2C+col23%2C+col24%2C+col25%2C+col26%2C+col27%2C+col28%2C+col29%2C+col30%2C+col31%2C+col32%2C+col33%2C+col34%2C+col35%2C+col36%2C+col37%2C+col38%2C+col39%2C+col40%2C+col41%2C+col42%2C+col43%2C+col44%2C+col45%2C+col46%2C+col47%2C+col48%2C+col49%2C+col50%2C+col51%2C+col52%2C+col53+from+367892+where+col34+%3C+'1'+and+col53+%3D+'1'&h=false&lat=43.834526782236814&lng=176.484375&z=1&t=2&l=col1

  23. A great way to get environmentalists aboard for good science would be to pick a couple of dozen truly natural sites distributed around the world and put solar powered climate monitoring stations in the middle of them. Then ban all but backpackers within ten miles or so of the stations. Call them International Parks.

  24. “Sully says: December 23, 2010 at 11:09 amA great way to get environmentalists aboard for good science would be to pick a couple of dozen truly natural sites distributed around the world and put solar powered climate monitoring stations in the middle of them. Then ban all but backpackers within ten miles or so of the stations. Call them International Parks.”

    Gonna hire some international park police to enforce this ban? Good luck. Forrest Service enforcement in the US of A can’t keep the 4 wheelers out of the areas where they are not allowed.

  25. @Buddenbrook

    ‘Will we see a metropolis with population of 100 million during this century?’

    It’s hard to imagine that a metropolis of 100 million can be supported, even with tomorrows infrastructure technology. Of course it is easier to imagine if one don’t care for proper infrastructure.

    China comes to mind though, especially if their economy doesn’t crash, however they got a serious problem of populating their newly built cities so they go ghost towns. And they have serious problem in those cities that have grown faster than their infrastructure (electricity, sewers, water, communication) can keep up with. And now they also have serious problem with particulate pollution from sand and coal dust, and of course crappy cheap combustion in cheaper cars which amount has already outgrown the communication infrastructure of roads (this in cities that went from “no cars” to new roads and too many cars in ten years’ time.) Cities along the Yellow river use so much of the water that it often time don’t reach the sea, and the less water the higher the concentration of pollutants. Their water problem, as I understand it, is more a lack of regulation of mandatory cleaning and filtering of waste water, especially industrial waste water which tend to be laden with chemicals, on the one hand, and a logistical problem when it comes to fresh water usage (which they don’t seem to have any control over.)

    (Apparently a lucrative business in the Yellow river is body fishing, which is fishermen who fish out corpses from the river on a daily basis. Sounds macabre but with more ‘an 400 million people living in the river basin . . .)

  26. Sully, it still doesn’t work. I live near several National Parks, in the Rockies. I can say for certainty that while century level averages might mean something our local weather is HIGHLY variable, dependent on the Pacific Ocean even though we’re a 12 hour drive away from it. Occasional cold fronts slump down the Rockies too, and can park us in bitter cold for weeks at a time. Unless you want to have thousands of these International Parks.

    This is one of the reasons I believe a “global temperature” is completely unobtainable, and claims of having one are laughable. Especially when 70% of the surface area is a fluid. In fact, while some are drawing hockey sticks and panicking over tiny increases in the record, I’m always amazed at just how stable our planet keeps it’s temperature.

    Also, the fewer thermometers there are in the record, the warmer the record is. Go figure.

  27. Les Johnson says:
    December 23, 2010 at 7:54 am (Edit)

    Anthony: Is there any way to calculate how many temperature stations are in urban areas? If a high percentage of stations are in urban settings, it would be safe to assume that a high percentage of warming is actually UHI.

    yes, one can calculate the number of stations with “urban” areas, but you need a definition of urban.

    How do you want to define “urban” or rather how do you want to define Rural?

    I’ll post up some figures that will surprise people.

  28. In terms of urban Impervious Surface Areas (ISA), a 2007 NOAA study found that about 0.5% of the world’s land mass is ISA (1.5% of the US). Of course this does not count grass, woods, and other natural landscapes that are incorporated into urban areas. The GRUMP project takes a broader view.

    See http://pielkeclimatesci.wordpress.com/2010/09/10/guest-post-large-scale-climate-modification-agriculture-urban-heat-islands-are-changing-regional-and-continental-climates-by-bill-dipuccio/

  29. Various measures of urban/rural

    Source: GHCN V3. Locations corrected by WMO ( nov 30th)

    table(Inv$GrumpUrban)

    0 1 2
    326 3282 3632

    0 = that station location is in the water ( islands and coastal locations are hard to locate
    within 1 km)
    1. The station is rural.
    2. The station is urban.

    How about Impervious surface area?

    1. Rural is defined as NO impervious surface within 1 km

    ZeroIsa <- Inv[which(Inv$Isa==0),]

    [1] 1445

    2. Rural is defined as less than 1% of the surface is impervious

    ZeroIsa <- Inv[which(Inv$Isa nrow(ZeroIsa)
    [1] 2567

    How about Nightlights?

    No nighlights using the Hansen version:

    ZeroLight nrow(ZeroLight)
    [1] 2812

    how about no lights within 10km of the station using the newer 2006 lights

    ZeroLight nrow(ZeroLight)
    [1] 648

    What do the value of Grump look like there

    table(ZeroLight$GrumpUrban)

    0 1 2
    105 510 19

    So, 510 of the stations that have no lights within 10km are Rural by Grump standards

    Then we can limit the population density to 14 people per sq km, and eliminate any stations still in the water and you end up with about 400 stations that.

    1. are not mislocated in the water
    2. Have a grump rural indicator
    3. Have no lights within 10km of the station

    We can check for impervious surfaces at these sites. It looks like there might be one outlier. And we can check for airports

    summary(Rural$Isa)
    Min. 1st Qu. Median Mean 3rd Qu. Max.
    0.0000 0.0000 0.0000 0.2071 0.0000 16.0300
    > summary(Rural$Airport)
    Mode FALSE TRUE NA’s
    logical 321 93 3

    After eliminating all airports we have 321 stations.

    How much did they warm?

    Well, from 1979 to 2009 for stations that had “full” records ( >300 months of data including the first and last year )

    summary(D2$Slope)
    Min. 1st Qu. Median Mean 3rd Qu. Max.
    0.004355 0.022940 0.032600 0.033710 0.045540 0.057780

    That’s in degrees C per year so

    Minimum .04 C per decade
    maximum .5C per decade

    mean warming per decade at Rural .33 C

    The mean population density was less than 1 person per sq km from 1980 to 2000
    so no population growth.

    And one of the warmest:

    http://gallery.surfacestations.org/main.php?g2_itemId=7069

    Another warm one

    http://gallery.surfacestations.org/main.php?g2_itemId=7061

    but after all this screening you are down to 17 stations.

  30. Stephen Skinner, “For example Los Angeles consumes enough water to significantly lower the level of Owens Lake and prevent the Colorado from reaching the sea. This means there will be less moisture in the atmosphere in these areas increasing the likelihood of localised warming” – don’t forget that if you lower the humidity, you also lower the overnight minimum temperature at the same time as you raise the daytime maximums. Global warming is much more about higher minimums than it is about higher maximums, but since this doesn’t make dramatic news for TV audiences, the AGW alarmists ignore it.

  31. Steven Mosher has a point “how do you define urban”

    Different countries have different definitions and they vary from a few hundred per square km to several thousand per square km. Once we decide exactly what it is we still can probably concede that about half the world’s population lives in some sort of urban area and the other half live in rural areas (other than urban).

    My question about temperature measurement sites is how many are in populated areas and how many are in non populated areas? I would guess that over 95% are in populated areas and do not represent what most of the earth actually is (unpopulated).

    Bernie

  32. Bernie McCune says:
    December 23, 2010 at 1:51 pm (Edit)

    Steven Mosher has a point “how do you define urban”

    Different countries have different definitions and they vary from a few hundred per square km to several thousand per square km. Once we decide exactly what it is we still can probably concede that about half the world’s population lives in some sort of urban area and the other half live in rural areas (other than urban).

    My question about temperature measurement sites is how many are in populated areas and how many are in non populated areas? I would guess that over 95% are in populated areas and do not represent what most of the earth actually is (unpopulated).

    ########

    the point is this. If you are looking for areas that are free from UHI you have to tie your definition of urban/rural to the features that cause UHI and also those that cause urban cool parks.

    1. Building height.
    2. Surface materials.
    3. Canopy cover.
    4. waste heat.
    5 the character of the rural landscape

    Not an easy job.

  33. Codetemp,
    My point, even if a bit tongue in cheek, was that continuous records from a set of such isolated stations, all similarly constructed and maintained, over a long period of time would at the least not be subject to arguable manipulation by folks with a political or other agenda.
    I can’t be the only non-scientist who finds it amazing that scientists are arguing over the meaning of temperature records since the 1940′s or so, by which time relatively precise observation tools became so cheap as to be throwaways.
    I’ll be looking forward to Anthony’s posting of a listing of rural observations that have been kept for a long time since, by what I’ve seen, the trend of those raw observations will be much more believable than the massaged data, based on what I’ve read here.

  34. Jim G,
    Give the most ardent Sierra Club or GreenPeace members well defined hunting licenses and control over dedicated attack drones and there won’t be any problems with four wheelers or any other motorized traffic in such sanctuaries. I have no doubt they would happily, even joyfully, police the parks given some of their writings.

    You would, of course, want to make doubly and triply sure that the drones were programmed to prevent use outside the parks.

  35. Bernie McCune says:
    December 23, 2010 at 1:51 pm (Edit)

    Steven Mosher has a point “how do you define urban”

    “My question about temperature measurement sites is how many are in populated areas and how many are in non populated areas? I would guess that over 95% are in populated areas and do not represent what most of the earth actually is (unpopulated)”

    What do you mean by populated? If you define that I can tell you. Specifically, how many people per sq km constitutes “populated?” I’m not trying to be difficult. But if you said 15 people per sq km then it would be one answer and 89 would be another.
    What uo want to know is what did the people do to the land? Airports for example, rural airports have very LOW population counts. Nobody lives there. See, it’s not an easy problem

  36. Most airports I can remember are now surrounded by “urban” areas (or certainly on the edge of them) even if they are not themselves “populated”. Urban to me would mean any series of 1 km^2 grids that have hundreds of people in those grids. If the measuring station happens to be located within several km^2 with only 10s of people in them (such as an airport) but are surrounded by grids with hundreds or thousands of people in them I would still classify the site as urban. The main point I wanted to make is that so very few of the measuring stations are located inside forests and woodlands, permanent pastures (steppes), or other places like deserts, mountains, arctic tundra which make up the vast majority of the earth’s land surface. The temperatures that many of the present sites are measuring are therefore more likely to be the other form of man made global warming (UHI).

    After looking into the use of land surface temperature measurements as an indicator of global climate activity, I must say that I don’t think it is ever going to be effective. However, if in spite of that cautionary note we decide to try anyway, I would hope we would do a much better job of it than we have so far. Anthony has documented the many shortcomings of many of these sites. And the fact that many of the sites ARE at airports or in the middle of urban areas is a testament to the fact that they were never meant to be used for climate analysis.

  37. For the continental US, the 2004 constructed surface area survey (NOAA) was very thorough (more thorough than the 2007 global survey). Scientists used Landsat data, satellite observed nighttime lights, U.S. Census Bureau road vectors, and high resolution aerial photographs.

    However, population density was not considered. So, one cannot assume that a ‘rural’ station is class one. Station classification has to be done one at a time–as Anthony has shown us.

    See Elvidge, C. D., C. Milesi, J. B. Dietz, B. T. Tuttle, P. C. Sutton, R. Nemani, and J. E. Vogelmann (2004), U.S. Constructed Area Approaches the Size of Ohio, Eos Trans. AGU, 85(24), doi:10.1029/2004EO240001 http://www.ngdc.noaa.gov/dmsp/pubs/ElvidgeEtAl-EOS-ConstructedAreaApproachesSizeOfOhio.pdf

    Summary in AGU News: http://www.agu.org/news/press/pr_archives/2004/prrl0423.html

    See also Elvidge, C.D.; Tuttle, B.T.; Sutton, P.C.; Baugh, K.E.; Howard, A.T.; Milesi, C.; Bhaduri, B.; Nemani, R. Global Distribution and Density of Constructed Impervious Surfaces. Sensors 2007, 7, 1962-1979. http://www.mdpi.com/1424-8220/7/9/1962/pdf

  38. Steven, you mean rural warming like this:

    http://gallery.surfacestations.org/main.php?g2_itemId=55871

    Just happened to be the random pick on SurfaceStations.

    I’m wondering where all of the excess energy went to. Missing? Maybe hiding or maybe they are storing it or maybe it never comes to this town. ;)

    How does any point on earth escape the effect of 1.5C rise if excess global energy, therefore temperature, is the cause? It can’t. But there it is and there are many other small towns whose temp graph look similar, level or down. Now a 0.3C rise I’ll accept, to me it happened, and then this other is just variance excursions on various scales.

    Big city UHI, it’s real but in reality has little to do with ‘global warming’ but to create bad data, bad science, and allow the building of insidious scientific lies.

  39. Area of Texas / current estimate of Earth’s human population = ~2,000 ft^2 per human. It’s true, do the math yourself. Then take the quotient you get and divide it into the land surface area of Earth, then into the total surface area of Earth.

    Are you getting the picture? Earth != overpopulated. “Trantor level population density” would be well over a trillion people. The total surface area of Earth could be divided into 2,745,191,623,680 – 2,000 ft^2 parcels, using this 196,940,400 I found for miles^2 for Earth’s total surface area. Make that several trillion packed elbow to elbow in a multi-story building that covers an entire Earth sized planet. Even if necessary hallways, HVAC, water, sewer etc services uses half the space and cuts it down to 1,000 ft^2 per human, the 2,745,191,623,680 number is still the two-trillion pound gorilla in the room, and every individual still has plenty of space to rattle around in.

    Science fiction authors have vastly undershot the mark, many times, in super-population dystopic tales. A 100 level building, and having to import *all* food and other resources, that just ain’t plausible at all. With 1,000 ft^2 per person, that’s 270 trillion, there’s still gobs of elbow room, and the roof could all be covered in high density hydroponic farm.

    More plausible, four story building, bottom floor all services, middle two floors living space, top floor food production. Cut the room size down to 200 ft^2 and again give 1/2 the space to etc and the pop per floor is 13,725,958,118,400 or 27,451,916,236,800 total. There we go! A mere 27.4 trillion beings in a world girdling building. Not quite 70,000 per mile^2. Monaco’s density is over 42,000 mile^2, so I suppose the 27.4T number could be within spitting distance of “packed in elbow to elbow”, as long as it’s kept to only two floors – but 200 square feet per person is ridiculously generous, in really dark and dingy dystopic Sci-Fi.

    If anyone wants to use any of this in a story, go ahead. It’s just simple math anyone *could* do, if they’d bother to do it instead of spouting off about Earth being “overpopulated”.

  40. There is certainly some controversy about land use figures due mostly to definitions and the inability to obtain really good data. Satellite imaging and the clever manipulation of it is now beginning used to get to the bottom of this problem. More precise definitions need to be developed. A little more than 70% of the earth’s surface is covered by water.

    Some folks in the know have estimated that Urban land use at this point is closer to 2.4% of the earth’s land area and they speculate that the 3% figure is being used to cover the uncertainty. I did some study of use of land for roads and parking lots and found some data that indicates that somewhere between 1.5% and 2% of the earth’s land surface is covered by roads and parking lots. Probably all the parking lots are found in urban areas so they would be included in the 3%(or perhaps 2.4%) of urban land. Some unknown percent of the roads can be found on urban land while the rest lie in rural areas.

    Of the approximately 32% of the earth’s forests and woodlands about half of it mostly resides in the Siberian part of Russia. Jim Bowyer has done some interesting work on busting myths about forests in the U.S. in particular. Facts vs. Perceptions is a very interesting piece he wrote in 1995 that is well worth reading. Often people make statements about the state of our forest environment that are obvious propaganda. Find the pdf report here:

    https://www.dovetailinc.org/files/u1/Factsvs_Perception.pdf

    Bernie

  41. I should have said that of the 32% of the earth’s land covered by forest and woodlands about half of it mostly resides in the Siberian part of Russia.

  42. Steven, you mean rural warming like this:

    http://gallery.surfacestations.org/main.php?g2_itemId=55871

    Just happened to be the random pick on SurfaceStations.

    I’m wondering where all of the excess energy went to. Missing? Maybe hiding or maybe they are storing it or maybe it never comes to this town. ;)

    ###############

    Well if you look at the distribution of trends for ALL stations you will find some that are zero or below. The vast majority ( both rural and urban) are positive. So, yes it is getting warmer. We know this from UAH and RSS. no UHI in those measures.
    It is an interestng question why certain areas can have a negative trend while the rest of the globe does not. Kinda like an eddy in a stream.

    “How does any point on earth escape the effect of 1.5C rise if excess global energy, therefore temperature, is the cause? It can’t. But there it is and there are many other small towns whose temp graph look similar, level or down. Now a 0.3C rise I’ll accept, to me it happened, and then this other is just variance excursions on various scales.”

    It can most certainly happen and does.

  43. Steven Mosher,
    I can understand why one or a few stations would buck a trend; but just to be clear, are you saying that the majority of clearly rural stations with long records show a positive trend since 1950? When I skimmed around the surfacestations.org site (clicking on the random pick button picture in the lower left hand corner) after seeing the other Steven’s link I found a half dozen in a row that seemed to have no trend at all or a downward trend before I found a couple that had a positive trend. A small sample; but it made me curious.

  44. We travelled by small boat through Indonesia 2000-2001. We found all the “uninhabited” islands listed in the Pilot Guides from WWII were in fact now inhabited. Even small sand cays were packed with stilt houses.

    Around 1900, about 4% of the earth’s surface was used by humans in total, including agriculture. Now we use 10 times as much, with agricultre at 37% and urban use at 3%.

    If there is a AGW effect, land use would be top of my list. Since 1850 CO2 has apparently doubled, with about 1 degree C warming. There is no reason to expect the next doubling of CO2 will have a greater effect.

  45. Bill DiPuccio says:
    December 23, 2010 at 6:35 pm

    “For the continental US, the 2004 constructed surface area survey (NOAA) was very thorough (more thorough than the 2007 global survey). Scientists used Landsat data, satellite observed nighttime lights, U.S. Census Bureau road vectors, and high resolution aerial photographs.

    However, population density was not considered. So, one cannot assume that a ‘rural’ station is class one. Station classification has to be done one at a time–as Anthony has shown us.”

    Using Anthony’s class 1 stations to calculate at the US annual average temperature anomaly trend made no difference, from the trend calculated from all the stations in the US data base.

    So while the temperature from these stations is influenced by their improper configuration it turns out that it doesn’t seem to affect the temperature changes over time since 1950. The temperature anomaly trend looks the same for class 1 stations as for the total data base.

    [The data they used was preliminary from Mr. Watts, at only 40% surveyed. There were only a handful of class 1 stations. The data was used without his consent, and not yet quality controlled. Like SkepSci, you cite it because it is convenient to what you want to believe. Nobody seems to care if the data was prelim, not QC, or that Mr. Watts hadn’t even done an analysis yet. They were just interested in smacking down the project before Mr. Watts had a chance to publish. Mr. Watts has completed the project and has over 1000 station now, and a peer reviewed paper is in process. I wouldn’t be so quick to jump to conclusions just yet. You really should read up on it here. There are things you obviously know nothing about related to the project, just like skepticalscience. see this: http://wattsupwiththat.com/2010/01/27/rumours-of-my-death-have-been-greatly-exaggerated/ -moderator]

  46. Baa Humbug says:
    December 23, 2010 at 8:55 am
    Obviously the actual space occupied by humans is minimal. It’s the space required to grow and raise our food that’s the problem.
    Conceivably, if power was really really cheap and plentiful, say modular nuclear plants the size of phone booths, we could build multi storey farms right in the cities and towns.
    No need for long distance transport, no need for long term refigeration etc etc
    Level 5 – tomatoes. Level 7 – green beans lol

    No problem
    focusfusion.org (5MW from a shipping container, ¼¢/kwh.)
    +
    http://www.verticalfarm.com/ or

    http://weburbanist.com/2008/03/30/5-urban-design-proposals-for-3d-city-farms-sustainable-ecological-and-agricultural-skyscrapers/

    Will that do?

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