From Dr. Roy Spencer’s Global Warming Blog
The urban heat island (UHI) was first described by Luke Howard in 1833 for London, England. Urban area air temperatures are almost always warmer than their rural surroundings, especially at night. Thus, the average human experiences warmer temperatures than they would if they lived in wilderness conditions.
This has nothing to do with global warming, and would occur even if there was no long-term ‘global warming’. In fact, since over 50% of the Earth’s population now lives in urban areas (expected to increase to nearly 70% by 2045), the temperatures humans actually experience would continue to break high temperature records even without climate change. For reference, the following plot shows the increase in global population between 1800 and 2023.
Our new global gridded UHI dataset allows one to compute just how much warmth (vs wilderness conditions) the average person experiences merely because most people live where human settlements cause localized warming. The following plot shows my computed ‘demographic warmth’ (during June, July, and August) experienced by the average human and how it has changed since 1800. For comparison I’ve also plotted the area-average temperature departures from the 1885-1984 average of the land portion of the HadCRUT4 thermometer dataset.
What can one conclude from this plot? At a minimum it shows humans choose to live under warmer conditions just by living in densely populated areas — and increasingly so. I will leave it up to the reader to decide if it shows anything beyond that. Note that this does not include the effect of (for instance) the migration of the U.S. population from colder to warmer latitudes, which would show an additional source of demographic warming. The warming shown by the red curve is only for urban effects relative to wilderness conditions at the same location.
Now, don’t be confused about what this means regarding the UHI impact on the thermometer measurements — that’s a different subject. All this shows is an metric of human-centric experienced warmth, not a thermometer-centric estimate of how much warming from the thermometer network can be attributed to UHI effects. The UHI effect on air temperature is due to a variety of processes associated with human settlements, such as replacement of vegetation with buildings and impervious surfaces and generation of waste heat that change the daily energy budget of those locations. Our UHI dataset simply approximates all of those processes using population density as a proxy, a choice made for us by the fact that it is the best (and possibly only) long-term dataset that exists to analyze the UHI problem.
“What can one conclude from this plot? At a minimum it shows humans choose to live under warmer conditions just by living in densely populated areas — and increasingly so.
File this under association is not causation. Because of industrialization people are moving to cities.
I am retired. I move to where it cooler in the summer and warmer in the winter.
Conclude? Global warming at the present level is *NOT* a catastrophe.
Commonly known as a “snow bird”.
Perhaps mass human migration will increasingly become a wide-scale phenomenon as the tethering of employment with urban habitation trend continues to fall.
The transportation costs (and carbon footprint) twice a year will be easily offset by lowered energy usage for home heating and air conditioning.
As I’ve said before, if rising temperatures and the threat of extreme weather events associated with them were such a threat, why hasn’t there been a major population shift northward to places like Alaska, Labrador, Scandinavia, Siberia, and Manchuria, among others, particularly since there’s plenty of room in all of them? Or maybe people feel that warmer climes don’t pose such a threat in the first place and therefore it’s worth taking the chance that they won’t be adversely impacted , especially when they’re reminded (but never by the alarmists) that far more people globally succumb to cold than heat
‘Global, regional and national burden of mortality associated with nonoptimal ambient temperatures from 2000 to 2019: a three-stage modelling study’
https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(21)00081-4/fulltext
For a few years in my life, I lived in a moderate sized city. Neither the city nor I was much improved by the association. 🙂
Warmth is comforting.
Haven’t there been stories of alarmist morons who moved far north to escape global boiling?
Did they freeze to death.
Haven’t seen those stories yet- but looking forward to them. 🙂
There was the case of a Professor that took his class to the Arctic to witness, first hand, its relatively ice free state. Their boat got stuck in the ice and they had to be rescued by an Icebreaker.
There have been events of alarmist morons who traveled far north (and south) to peruse the effects & impacts of global boiling, who were then themselves impacted by, and and needed to be rescued from, the cold. But haven’t seen the inevitable death yet.
Have there been any studies regarding ‘precipitous decline, and sparsity of polar bears’ that have resulted in death by polar bears?
Humans evolved in the “chilly” environs of Africa……
It is why we have cooling glands not warming glands.
“Hot / cold / warm / cool” are all personal conclusions.
That’s why people in the same space fight over the heating or air conditioning settings.
There are no right or wrong answers to this.
No kidding. I once had a roommate who was from Mississippi and insisted on setting the thermostat at “Sahara Desert”, and I’m from Colorado and feel comfortable sleeping at night when I can almost see my breath…
I still fail to reason why those coming to Florida will set their indoor night time thermostat to 70F and then cover themselves with a blanket.
Just search “best temperature for sleep” and then you will know.
I prefer 65 f for sleeping. At that temperature I use a moderate weight blanket, my wife adds another layer. A little colder is fine also.
Anything above about 72 f makes is uncomfortable for me to sleep. I will wake often and will not be well rested.
I guess you, Tom, in FLORIDA have acclimated to sleeping in overly warm (to me) conditions.
BTW My primary residence for the last 40+ years was Las Vegas. I never got used to sleeping in a warm room. Thank god for science and energy. (AC and abundant on demand electricity)
My point was not what temperature you like to sleep in, but rather why lower the temperature then have to cover yourself with a blanket to stay warm. Why not raise the temp a bit and just use a sheet? Or you can achieve the same temperature effect with ceiling fans.
Does anyone have a temperature record (graph) going back before 1880? I know the CAGW crowd insists on starting in 1880, my problem is we were mostly out of the little ice age by then. A record going back to 1700 would also be considered pre industrial. I can’t find one.
CET is about the only long-term record available
The base line for that graph is 1961-1990 so it should be considered cherry pie.
Thank you, this is very helpful.
HadCRUT and BEST, both go back to 1850. BEST also has a land only global data set going back to 1750 – though obviously the uncertainties are huge going that far back.
Thank you, this is very helpful.
How dare they move to warmer climates!
The Global Population chart looks a little off. It indicates the current population (2023) as half way from 8B to 9B (8.5B) which is a bit high. Conservative estimates place the current population at 8.071B.
Apparently ‘everyone’ wants to move to Dubai where the coldest winter day is as hot as summer in the UK, and the summer night minimum is 30C and the max. averages 44C.
I suppose unlike us, at least they will always have the energy and wealth to afford the aircon!
https://www.dailymail.co.uk/travel/article-12715575/Where-world-wants-LIVE-Fascinating-map-shows-Dubai-number-one-city-people-globe-want-followed-Miami-Paris.html
How much does that have to do with their very low crime rate.
People like to go fun places where it is SAFE.
Australia stupidly offers overpopulated Tuvalu (that is known to be and provably growing in area) sanctuary to residents in Australia against future possible impacts of further
overpopulationclimate change.https://www.abc.net.au/news/2023-11-10/tuvalu-residents-resettle-australia-sea-levels-climate-change/103090070
I find it a strange world where Antarctica, the Torres Strait & Tuvalu are recording ever increasing sea level rise – but Tasmania and Sydney .. the very mid latitudes most susceptible by sea level rise (according to the IPCC, due to global warming) are not.
As I was young in the mid 70ies I moved from Berlin, Germany to southern France, Côte d’Azur near Nice.
The reason, cold weather in Germany….
Obvious correlation / causation issue here. Are people moving to cities because it’s warmer, or are cities warmer because that’s where most people are living?
If it was just a matter of choosing to live where it was warmest, would nearly everyone be living in the tropics by now?
Also, I wonder how many who choose to live in cities in the US, also demand the right to have air-conditioning?
Why ?
Those that demand a right, that is to be provided, usually do live in the cities.
To satisfy your wonder, all you have to do is pick the city and check the politically affiliation.
The ones with the ‘D’ are the ones that would be demanding a right “to have something (provided)”.
The ones with the ‘R’ won’t be demanding the right to have something, just the right to be left alone and not be interfered with if they chose to acquire something on their own.
“‘Demographic Warming’: Humans Increasingly Choose to Live Where It’s Warmer”
True. Some woke friends of mine living in northern VT just moved to SC.
Testify!!!!
I can accept that people move to a warmer climate such as retiring to Florida or Sothern Spain from colder climates, but I doubt that people use it as a criteria for moving into cities from the surrounding environment. It is almost certainly due to economic reasons.
Having said that, the received wisdom when I was growing up was that historically the west London suburbs were populated by the relatively affluent because the prevailing winds swept the pollution and foul smells from west to east.
Serious sewage-works building in London only began in earnest when the summer stench from the river Thames became intolerable in the Houses of Parliament.
plus ça change…
plus ca change – yep the stench goes the other way now!