Study: 'Heat island' effect could double climate change costs for world's cities

From the UNIVERSITY OF SUSSEX and overheated climate science department, comes a claim that just doesn’t seem plausible, suggesting that in the future, nearly 11% of a “worst-off city” gross domestic product would be consumed by UHI boosted climate change. On the other hand, the study is by Dr. Richard Tol, who is well respected by the climate skeptic community. He does have a point about “the effects of uncontrolled urban heat islands”

Urban Heat Island profile Image from Lawrence Berkeley Labs

‘Heat island’ effect could double climate change costs for world’s cities

Overheated cities face climate change costs at least twice as big as the rest of the world because of the ‘urban heat island’ effect, new research shows.

The study by an international team of economists of all the world’s major cities is the first to quantify the potentially devastating combined impact of global and local climate change on urban economies.

The analysis of 1,692 cities, published today (Monday 29 May 2017) in the journal Nature Climate Change, shows that the total economic costs of climate change for cities this century could be 2.6 times higher when heat island effects are taken into account than when they are not.

For the worst-off city, losses could reach 10.9 per cent of GDP by the end of the century, compared with a global average of 5.6 per cent.

The urban heat island occurs when natural surfaces, such as vegetation and water, are replaced by heat-trapping concrete and asphalt, and is exacerbated by heat from cars, air conditioners and so on. This effect is expected to add a further two degrees to global warming estimates for the most populated cities by 2050.

Higher temperatures damage the economy in a number of ways – more energy is used for cooling, air is more polluted, water quality decreases and workers are less productive, to name a few.

The authors – from the University of Sussex in the UK, Universidad Nacional Autónoma de México and Vrije University Amsterdam – say their new research is significant because so much emphasis is placed on tackling global climate change, while they show that local interventions are as, if not more, important.

Professor Richard S.J. Tol MAE, Professor of Economics at the University of Sussex, said:

“Any hard-won victories over climate change on a global scale could be wiped out by the effects of uncontrolled urban heat islands.

“We show that city-level adaptation strategies to limit local warming have important economic net benefits for almost all cities around the world.”

Although cities cover only around one per cent of the Earth’s surface, they produce about 80 per cent of Gross World Product, consume about 78 per cent of the world’s energy and are home to over half of the world’s population.

Measures that could limit the high economic and health costs of rising urban temperatures are therefore a major priority for policy makers.

The research team carried out a cost-benefit analysis of different local policies for combating the urban heat island, such as cool pavements – designed to reflect more sunlight and absorb less heat – cool and green roofs and expanding vegetation in cities.

The cheapest measure, according to this modelling, is a moderate-scale installation of cool pavements and roofs. Changing 20 per cent of a city’s roofs and half of its pavements to ‘cool’ forms could save up to 12 times what they cost to install and maintain, and reduce air temperatures by about 0.8 degrees.

Doing this on a larger scale would produce even bigger benefits but the vastly increased costs mean that the cost-benefit ratio is smaller.

The research has important implications for future climate policy decisions – the positive impacts of such local interventions are amplified when global efforts are also having an effect, the study shows. Professor Tol said: “It is clear that we have until now underestimated the dramatic impact that local policies could make in reducing urban warming.

“However, this doesn’t have to be an either/or scenario.

“In fact, the largest benefits for reducing the impacts of climate change are attained when both global and local measures are implemented together.

“And even when global efforts fail, we show that local policies can still have a positive impact, making them at least a useful insurance for bad climate outcomes on the international stage.”


The study:

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May 30, 2017 6:10 am

The urban heat island occurs when natural surfaces, such as vegetation and water, are replaced..
Didn’t we just read a study that said the earth is greening…and more trees make it hotter?
reduce air temperatures by about 0.8 degrees….
… anyone would notice

Patrick MJD
Reply to  Latitude
May 30, 2017 6:29 am

Yeah like here in Aus the SMH Weather page states temps as 32c, lol, feels like 32.4c. Yeah sure!

Bryan A
Reply to  Patrick MJD
May 30, 2017 9:51 am

I guess people who work in cities just won’t know what Productivity is anymore

Reply to  Latitude
May 30, 2017 7:40 am

Although cities cover only around one per cent of the Earth’s surface
if you consider oceans. cities cover 4% of the land. about the same area as used in total including agriculture 150 years ago. now including agriculture we use 40% of the land surface area.

May 30, 2017 6:10 am

Thank you, Anthony has done a great job with the Climate Station bad settings.
I thought you might be interested in my interview on Nuclear Energy vs. Renewable Energy and Climate Change: Here is the show page for the Horsting interview:

Joe - the non climate scientist
May 30, 2017 6:10 am

Are the climaistas admitting that the UHI may bias the land temp readings?

Reply to  Joe - the non climate scientist
May 30, 2017 6:16 am

Possibly, it is hard to keep the lies straight.

Reply to  LoganSix
May 30, 2017 9:22 am

Yeah, what’s up with dat? I thought for years they’ve been telling us UHI doesn’t exist so it can’t bias the temp readings. The old adage about not being able to keep your lies straight seems to be true.

Bryan A
Reply to  LoganSix
May 30, 2017 9:52 am

That can happen when you tell to many of them (lies)

Reply to  Joe - the non climate scientist
May 30, 2017 7:23 am

That’s OK Joe – Temperature readings from stations at cooler altitudes should balance the overall results … oh, but wait, those were shut down, weren’t they.

Reply to  Joe - the non climate scientist
May 30, 2017 7:42 am

Wasn’t the consensus that UHI caused cooling, so NASA/GISS needed to adjust temperatures upwards to correct for this?

Reply to  ferdberple
May 30, 2017 9:42 am

Wasn’t the consensus that UHI caused cooling, so NASA/GISS needed to adjust temperatures upwards to correct for this?

That’s what the warmistas say. Richard Tol is not a consensus warmista, but a bad naughty dissident/deníer.
Anyway, if “Study: ‘Heat island’ effect could double climate change costs for world’s cities”, then you could headline it as “Study: Urban heat island might be causing 50% of the cost of climate change”. Not that UHI existed, but it still could make things worse. /sarc

Reply to  ferdberple
May 30, 2017 9:45 am

Well what else could explain he need to adjust modern temperatures upwards?
(seems NOAA may have removed this image from their website… Not too good for their reputation)

Reply to  ferdberple
May 31, 2017 1:01 am

Jeff in Calgary on May 30, 2017 at 9:45 am
Maybe this is a somewhat more actual variant of what you try to show us?

Reply to  Joe - the non climate scientist
May 30, 2017 2:10 pm

I think what this study says, in so many words, is fit ‘cool pavements and roofs’ – get rid of UHI – and CAGW will go away further and faster than unicorn f@rts.
I appreciate that the authors didn’t phrase it in those exact terms [their loss], but that is pretty much what they imply.
No need for hyper-conflabs like Paris [with the benefits to all branches of the local economy].
No need for treaties that aren’t treaties but pious wish-lists of folk who don’t seem too keen on Western civilization (Barrie, you know who I mean. And Jeremy, too, of course).
No need to mangle raptors across the Northern Hemisphere.
No need to seek rare-earth metals found, currently, mostly in China.

RW Israel
Reply to  Joe - the non climate scientist
May 30, 2017 9:34 pm

Apparently it hasn’t happened yet, according to the quote, but will be a dangerous problem in the future, if you want to believe that.

May 30, 2017 6:11 am

If city centers are that much warmer, then they can grow food that might not grow in their Hardiness Zone. Just think of the boon for all those hipster restaurants in downtown areas that could grow their own fresh kale and jack fruit on the roof of their skyscrapers!

Reply to  LoganSix
May 30, 2017 9:45 am

Why cale? You would of course do the most sustainable thing, which is definitely not kale but something with high energy / protein content. Like grasshoppers, or edible larvae.
Sorry, my bad. If you put a hipster culturing kale, the result is a lot of protein.

Reply to  Hugs
May 30, 2017 9:46 am

It seems spelling is diffikult. My bad again.

May 30, 2017 6:18 am

Easy solution.
Don’t live in big cities.

John Bell
Reply to  MarkW
May 30, 2017 6:51 am

Unless it is a cold climate and you like warmth.

Reply to  MarkW
May 30, 2017 10:18 am

Then you use up land the furry little critters need and the farmers need. Oh, and the land for the wind turbines (that create their own heat sink when they turn) and solar panels. Whatever will we do then?

Reply to  MarkW
May 30, 2017 1:12 pm

Change zoning to stop large cities from increasing urban density-besides “cool” pavements and rooftops, limit new high construction possibly by limiting replacement buildings to 500 ft height to reduce the number of people. The World Trade Center rebuild is a good example. Instead of 2 110+ story towers with 3.8million square feet and 5 other buildings with 9.6 million square feet. The replacement One World Trade Center has 2.6 million square feet. By limiting replacement buildings and spreading huge cities into substantially separated smaller ones the UHI would be dispersed and lowered over a wider area also reducing concentrated pollution and allowing for more green spaces.
Spacing smaller cities out could cut the UHI effect by as much as 4-5deg.F

Michael Jankowski
Reply to  Philo`
May 30, 2017 3:52 pm

UHI is a surface-area issue. Lowering building heights worsens the problem. And making One WTC smaller than the original WTC is not “spreading huge cities into substantially separated smaller ones.”

Russ Wood
May 30, 2017 6:20 am

So, as they have JUST found out, UHI is affecting the cities – what effect is this supposexd to have on GLOBAL climate? (Except, of course, for the fact that most of the GISS thermometers are now inside these areas).

Reply to  Russ Wood
May 30, 2017 6:57 am

Tol shows close to a 10 degree swing for UHI…
…I’m sure Giss allows for that

Reply to  Russ Wood
May 30, 2017 9:48 am

This is certainly a sneaky way for Dr. Tol to sneak local adaptation into the conversation. Especially since the study would appear to indicate it is a much more cost effective way to deal with this completely local phenomena.

May 30, 2017 6:22 am

“they produce about 80 per cent of Gross World Product, consume about 78 per cent of the world’s energy and are home to over half of the world’s population.”
Most manufacturing left the cities a long time ago.
At one time services had to concentrate in cities, because that’s where their customers and suppliers were.
With modern technology, this is no longer required.
The remainder of that 80% is just to service the population that lives in the cities.

Reply to  MarkW
May 30, 2017 8:32 am

Urban density is highly overrated. link

Tim Hammond
Reply to  MarkW
May 30, 2017 9:25 am

I’m not sure where you get the information that “Most manufacturing left the cities a long time ago”? In the UK, just about all manufacturing is in cities, unsurprisingly since manufacturing needs skilled workers of all levels, access to infrastructure and markets, and often likes to be close to innovation from universities or similar places.
The same applies to China and India, and as far as I know, most of Europe.

Reply to  Tim Hammond
May 30, 2017 10:01 am

Most manufacturing left the cities a long time ago

Depends on what you call manufacturing and what you call a city. IT industry is typically located in cities and bigger centres, because it does not require a lot of space, but it might require a prestigious location.
Heavy industry (manufacturing) is usually not situated in central metropolitan areas. Mines and mills are outside. Milk and timber are not produced or or even packaged in “cities”. Of course, urban areas include areas of manufacturing, but these typically from some distance of the city centre, or are located in a town definitely not callable as a city.
About innovation from universities. Right. Like climate science.

Reply to  Tim Hammond
May 30, 2017 10:12 am

Skilled workers exist outside of cities as well.
Those who live outside of big cities have access to infra-structure and markets.
There are good universities outside of big cities, plus there’s no guarantee that graduates will want to stay in those cities if they don’t have to.

Chuck Dolci
Reply to  Tim Hammond
May 31, 2017 8:44 am

I live in what is commonly referred to as “Silicon Valley”, the self proclaimed center of the hi-tech universe. All the IT and other tech firms are in the suburbs, populated by single family homes, nice green lawns and trees and parks and environmentalist mandated “open spaces”. Some chi-chi software firms have located to San Francisco, but the vast majority of firms are located on the Peninsula. I have no doubt that there is a small UHI effect, but Manhattan this ain’t. Although, to be fair, I would not call this manufacturing. The factory work was outsourced largely to overseas producers decades ago.

Michael S
May 30, 2017 6:27 am

As of this comment, I have not read the study, but the statements by the authors seems to indicate that they are ignoring a very very important fact about the past 150 years of warming. The daytime highs are not increasing. It is the nighttime temperatures that are trending higher which tick incrementally raising overall temperatures. This means that the “crisis” is not really that big a deal. We are not going to see spikes in daytime temperatures, just incremental increases in the overnights when temperatures are not that big a deal. In fact, like many things in a warming world, there may be an overall benefit as heating costs in winter urban areas may tick down, and we may prevent some cold related deaths. But I am sure the authors thought about this before writing the scary headline and press release.

Patrick MJD
Reply to  Michael S
May 30, 2017 6:32 am

And here in Aus we have had a “record” low May overnight. Apparently a 20 year, record, low. Not much in the MSM tho…

Convict en Australie
Reply to  Patrick MJD
May 30, 2017 8:24 am

Sorry PMJD but the Sydney Morning Herald of Doom was whining about how ccccccooolddd it was at 7˚C (~45˚F) overnight. Those poor, poor daaahlings, how they suffer from climate change./sarc The Yanks must be falling about launghing

Reply to  Michael S
May 30, 2017 7:47 am

…in a sane world that would mean less frosts, less freezes

Reply to  Michael S
May 30, 2017 7:52 am

But I am sure the authors thought about this before writing the scary headline and press release.
what if you live in a cold climate? isn’t UHI something to be wished for? Why is the assumption always that warming is bad?
For example, the first red blob below is Sussex. Why is the university as far south as you can get in the UK?
SUSSEXcomment image
Why is it not as far north in the UK, say near the Outer Hebrides (second red blob) if heat is a problem?
OUTER HEBRIDEScomment image

Reply to  ferdberple
May 30, 2017 10:05 am

Oh that is because the climate change hits Arctic the hardest. They could not possibly be situated there, as they’d be nearer to the ‘super-hot Arctic’ (Washington Post, 2016).

James at 48
Reply to  ferdberple
May 30, 2017 5:11 pm

I prefer Skye. And wee dram or three.

Reply to  Michael S
May 30, 2017 8:57 am

Well, when the temperatures rise, deaths due to cold exposure will decline. However, deaths decline across most species, bacteria, vermin, parasites and disease bearing vectors included. If we aren’t battling the elements we are battling everything else that wishes to thrive as well.

May 30, 2017 6:31 am

I live in a remote rural area of NE Wyoming. The temperature outside at 5 AM was 38 degrees F. At 7 AM it is now 73 degrees F, and rising rapidly. Am I going to die? 🙂 No, I’m going to leave for work soon and be very happy it won’t be -20 F for probably another 7 months.
What is WITH these people who worry so much about .8 degrees? Oh, and I can’t imagine living in a city at any temperature. 🙂

M Courtney
May 30, 2017 6:51 am

UHI is real. It may be correct if cities don’t adapt.
But, of course they will.
People will replace asphalt with lawn roofs and plant more trees for shade, if required.
The use of fountains to cool urban areas has been developed for over a thousand years.
So I think they have over-estimated the costs, if not the heat.

John Peter
May 30, 2017 6:51 am

So what about the cities in temperate and colder zones? During autumn, winter and spring they may enjoy lower heating costs to such an extent that the cost benefits may exceed the negatives during summer. This could actually be a zero sum game globally. I get the impression the authors assume that all big cities are in tropical or sub tropical zones.

Reply to  John Peter
May 30, 2017 9:18 am

The theory of CO2 global warming states that the polar regions will heat more. So far, we have seen very little heating in the tropical or sub tropical zones. I fail to see the negative side of global warming (if the warming we have observed is even caused by CO2…).

richard verney
Reply to  Jeff in Calgary
May 30, 2017 10:46 am

Also the warming is not that day time highs are getting higher, but rather that the night time lows are not quite as low. What is not to like about that?.

Reply to  John Peter
May 30, 2017 9:52 am

It is not much of a stretch to think of paving , roofing or siding materials that change their nature such that they can capture warmth by absorbing incoming radiation or reflect to keep cool. On a micro scale, shades, awnings and shutters already do that. The next 30 years are going to be interesting.

May 30, 2017 7:02 am

Are there economic benefits to concentrating people and business/industry in cities and if there are, how do they compare to the heat-island related costs? Clearly at some time in the past (and maybe still in the present) there were economic reasons for the growth of cities.

May 30, 2017 7:05 am

One of the nasty effects of urban and suburban environments is the modification of the hydrology of the area. When precipitation just runs off into the sewers and gets sent out to where ever they dump it, it does not sink into the soil and remove enthalpy later through evaporation and transpiration. As we know, a lot of heat is conveyed to the upper atmosphere by transevaporation to be dissipated. NASA puts it at 86.4 W/M^2 on average. Set that to zero in an area and you have a problem. Obviously, the open ocean has much more evaporation than land, but still. When you change the hydrology of an area in the way cities do, you will have a problem with heat. Of course the members of the Escathological Cargo Cult of the CAGW would not know heat of evaporation if they had to cool off with a swamp cooler. Thus, they will continue to blame hot cities on CO2 instead of extra energy dissipation and lack of transport.

May 30, 2017 7:06 am

“Overheated cities face climate change costs at least twice as big as the rest of the world because of the ‘urban heat island’ effect, new research shows.”
I think we should be careful about how we describe UHI. Instead of “climate change” costs, I would describe them as “local UHI costs”. Otherwise, we run the risk of people incorrectly conflating UHI with CO2 warming.

Patrick Hrushowy
Reply to  TA
May 30, 2017 7:38 am

That’s the point, precisely!

Reply to  Patrick Hrushowy
May 30, 2017 7:47 am

Every little bit of confusion helps keep the climate alarm funds flowing.

Reply to  TA
May 30, 2017 1:21 pm

How much of the increased cost is expensive power?

Reply to  ghl
May 31, 2017 6:56 am

Good point, ghl.

May 30, 2017 7:11 am

“This effect is expected to add a further two degrees to global warming estimates for the most populated cities by 2050.”
Now what exactly does this mean? Are they saying UHI is going to add two degrees to the global temperature? Or is this just restricted to the UHI cities? If it is restricted to UHI cities, then why are they calling it “global warming”?

Patrick Hrushowy
Reply to  TA
May 30, 2017 7:42 am

Could it mean that UHI effects are contanimating global temperature records?

Bruce Cobb
May 30, 2017 7:12 am

This is just a shameless attempt at conflating the faux issue of ” globalclimate change” with the strictly local issue of UHI. Cities have no business asking everyone else to help pay for cooling them down. If a state wants to do this to make their cities more attractive places to live and/or visit, fine, go for it.

May 30, 2017 7:14 am

“Higher temperatures damage the economy in a number of ways – more energy is used for cooling, air is more polluted, water quality decreases and workers are less productive, to name a few.”
I question the “workers are less productive” remark. Notwithstanding the difficulty of quantifying productivity, organization of work to improve productivity simultaneously contributes to UHI. In other words, UHI is the result of organizing work to improve productivity.
Now I can guess that what was meant was something along the lines of higher temperatures, ceteris paribus, make workers less productive. But “ceteris paribus” simply does not apply here because the UHI is resulting from changes designed to increase productivity.
This criticism could also apply to the “more energy is used for cooling.” Of course it is. And yes, this does lead to an increase in ambient temperatures. But is this a bad thing? Would workers be more productive in the absence of air conditioning?
Here’s the bottom line. Increasing productivity always comes at a cost. TANSTAAFL. Almost always this involves the use of greater energy throughput, and that always produces heat. But whether that is a “bad” thing or not is a “social” issue. And the only way to get to a fair, rational, and optimal result is to make sure all tradeoffs are properly priced with choices made in free markets. Before I retired, I occasionally taught a course in introductory microeconomics. A standard unit in the course was to get students to think about the “optimal” quantity of “pollution.” An ill-informed student’s first response is often to think that the optimal quantity of pollution is “zero.” But when the cost of that is pointed out to them, they begin to see that the issue is considerably more nuanced.
I think it is good to draw attention to the role of UHI in explaining any identifiable increase in global temperature (such as how siting weather stations can be biased by UHI effects). Anyone who has carefully considered the change in the skyline of a typical urban environment over the past 50 years will realize that the change has to have influenced global temperatures significantly. As a former student of geography, I think humans do have a significant impact upon the climate. But the current fixation on CO2 is clearly agenda driven, and ignores what are likely to be more significant factors.

Bruce Cobb
Reply to  blcjr
May 30, 2017 8:37 am

Your worry that UHI has affected or will affect global temperatures “significantly” is misplaced. It is a drop in the bucket, and of no global consequence whatsoever. Whatever effects man has on global climate are too small to 1) measure and 2) be of any concern. The effects are strictly local. It isn’t warming, in fact, that we need to be concerned about, but rather, cooling.

Reply to  Bruce Cobb
May 30, 2017 1:40 pm

I don’t necessarily dispute your reply, certainly not as to the greater concern being cooling than warming. As for UHI simply being “strictly” local it still “adds up.” Whether the sum total is too small to measure on a global scale is an empirical question. Can you cite any evidence one way or another, are are you just guessing?
Perhaps I should have made sure my statement about the “significance” of UHI was in comparison to the “significance” of CO2. (And this is just my guess.) Both may be too small to lose any sleep over (notwithstanding that loss of sleep has now been added to the dire consequences of rising CO2).

Roger Knights
Reply to  blcjr
May 30, 2017 10:07 am

“Higher temperatures damage the economy in a number of ways – more energy is used for cooling, . . . and workers are less productive, to name a few.”

They won’t be less productive if their workplaces are air-conditioned. That’s the case already in most of the American South & Southwest.

Jay Turberville
Reply to  Roger Knights
May 30, 2017 2:34 pm

Exactly. I was born in Phoenix, AZ in 1959 and have lived in the area all of my life. Over the years, many have asked me how I stand the heat, and the answer is simple – I say indoors where there is air conditioning when it is really hot outside. And yes, A/C power costs are high. But winter heating costs are low, and I don’t have to shovel snow, the city doesn’t have to plow streets, the streets and sidewalks don’t get damaged by frost heaving and cars don’t rust out from salting icy roads. It’s all a matter of trade-offs, and considering migration trends and the rate of growth of cities like Phoenix and Las Vegas, the trade-offs seem to favor warmer climates. Are people really fleeing toward disaster? Seems unlikely.

May 30, 2017 7:34 am

If this happened, wouldn’t people over time simply migrate northwards? Do they really think people are that stupid?

Reply to  BallBounces
May 30, 2017 10:23 am


May 30, 2017 7:46 am

I am fed up to the back teeth with continuously reading their scare-mongering scenarios where everything is always a “potentially devastating impact of climate change”.

Reply to  Luc Ozade (@Luc_Ozade)
May 30, 2017 10:09 am

Oh don’t you worry. Once they stop, there will a new generation with a totally updated set of scare-mongering scenarios. Doomsdayism is eternal.

May 30, 2017 7:48 am

The study is likely right.
The really high Social Cost of Carbon values are driven almost exclusively by costs in China. And the costs in China are mostly driven by increased costs for air conditioning.
If you add urban heat island effects to the models of Chinese cities in the SCC costing models, the SCC will increase significantly.
I have a great set of slides depicting this. Unfortunately, they are confidential. All of the information is in the publicly available SCC models. It is just structured to prevent the reader from noticing that the SCC is nonsense.

Reply to  vboring
May 30, 2017 8:01 am

Chinese cities in the SCC costing
you could substantially reduce the SCC by doing a Pol Pot. The UHI coupled with Paris Climate Agreement will no doubt force the Chinese back their farms to work the land and escape the murderous heat, and thereby remove the largest source of CO2 on the planet so the rest of us can drive around in Lincolns and Cadillacs with the AC cranked to the max.

Reply to  vboring
May 30, 2017 8:07 am

here is the solution to SCC and sea level rise.

May 30, 2017 7:54 am

total economic costs of climate change for cities this century could be 2.6 times higher
2.6 x 0 = 0

May 30, 2017 8:09 am

Sounds like a good paper. If it continues to warm, no matter the cause, then local UHI effects
could be serious during parts of the year. This type of paper brings attention to important issues in adapting to temperature increases.

Reply to  billw1984
May 30, 2017 9:16 am

…if you believe people in Miami are less productive than people in Cleveland

Tom Halla
May 30, 2017 8:16 am

It is all a matter of air-conditioning costs, therefore energy costs.

Reply to  Tom Halla
May 30, 2017 9:57 am

The costs of air conditioning compared to the increased production values of moderate temperatures is probably insignificant. When you think of the number of cubicle workers per hundred square feet of office space, vs the cost of keeping said space at 72 degrees F, I think the climate control costs are easily justified.

May 30, 2017 8:16 am

Having lived in Manhattan , there is no question UHI is a real and consequential problem , as opposed to RoW warming which I believe inconsequential .
Dense cities face not only the problem of additional solar capture and disruption of air flow , enormous amounts of additional energy are is injected thru air conditioners having to work harder just to overcome their own heat dumped into the streets .
Manhattan tries to air condition its subway stations . That alone dumps prodigious amounts of heat into the canyon streets . In many locations a 4 or 5c difference versus the edge of the island is all too sweatifying .
I took the “get out of town” solution exchanging my view of the Brooklyn Bridge and aroma of the Fulton Fish Market for a view of the still snow capped north face of Pikes Peak from an altitude of 2500m . No ac needed ( but the furnace in the am ) .

May 30, 2017 8:18 am

I think a bit more consideration of other factors is needed here. Yes heating up cities in warmer climates means greater need of air conditioning, but in cooler climates it means less energy for heating. UHI is more pronounced in cold climates and mainly affects nocturnal lows. In addition many large cities in hot climates may increase local vegetation and soil moisture compared to surrounding land thus assisting cooling. At any rate the claims are an admission of the importance of UHI as demonstrated by Anthony and others. Now if they can just admit how much that affect has deformed the trends from surface temperature records on land.

May 30, 2017 8:23 am

Just think how poor Singapore must be. It’s on the equator.

Reply to  Tab Numlock
May 30, 2017 11:04 am

As with all alarmist “studies”, they completely ignore benefits of warming. Cities with increased UHI will require less heating in Winter, and less snow/ice removal.
Another crap study hits the wall.

I Came I Saw I Left
May 30, 2017 8:23 am

The average may be global, but the effect is local. Learn to live with your choices and take the good with the bad.

May 30, 2017 8:39 am

So now lefty has a problem. The desire to concentrate the population into slums errrrr I mean cities and catastrophic heat island effect by doing so. Just more proof we have to kill off a bunch of humans in order to save Gaia.

May 30, 2017 9:08 am

Man made Climate Change pushes man made urban sprawl, it is a well known fact right? (sarc)

May 30, 2017 9:11 am

I thought that we had been assured that UHI was not real and had no effect. If this paper is true, maybe we need to revisit the impact of UHI on the terrestrial temperature records.

Bruce Cobb
Reply to  Jeff in Calgary
May 30, 2017 9:55 am

They are two different things; you have the temperature records, which UHI most certainly does affect, and the overall effect on global temperatures, which may be real, but are too small to measure.

son of mulder
May 30, 2017 9:29 am

Which came first the chicken or the egg?

Reply to  son of mulder
May 30, 2017 9:57 am


Reply to  DonM
May 30, 2017 10:26 am

Who laid it?

Reply to  DonM
May 30, 2017 10:31 am

something that was not quite a chicken, but was very close.

Reply to  son of mulder
May 30, 2017 6:13 pm

Good Question,
We can model it, but only by using spherical chickens…

Tom in Florida
May 30, 2017 10:08 am

“Although cities cover only around one per cent of the Earth’s surface, they produce about 80 per cent of Gross World Product, consume about 78 per cent of the world’s energy and are home to over half of the world’s population.”
Ah Ha! At least now they have identified the real cause of the supposed “global” warming. As such the solution is also very real. Do away with cities. Probably good to start with Detroit and Baltimore.

May 30, 2017 10:30 am

What a great potential tool for the control freaks that go by the title “Planner”. UHI mitigation regulations could be implemented (if politicians allow or encourage) that would make all other subjective regs pale in comparison … wetland, natural resources preservation, storm water, tree preservation (does anybody reading this have a tree on their property that they don’t really own?), building aesthetics would just be minor bumps in the road in comparison to the UHI mitigation.
The National Marine Fisheries zealots require that, for their review/approval, pre and post development comparisons of stormwater (volume and/or intensity) runoff mitigation is to be based on “lewis and clark times” for the pre-development impact. Using a similar standard for UHI mitigation would allow regulators unlimited power over areas that were covered with trees.
A whole new industry could be created (like the wetland industry that has grown up over the last 30 years), and the climate seance experts could move laterally into regulatory enforcement, of they could move into private practice and work for developers. Everybody is happy … except for those that think they own land.

Moderately Cross of East Anglia
May 30, 2017 11:03 am

Perhaps we don’t have to do with away with cities but just insist that everyone who lives and works in them paint themselves white to reflect sunlight back into space. We could do the roofs and roads too. Great for the sunglasses and sunscreen industries too – so always an upside if you look hard enough.

Reply to  Moderately Cross of East Anglia
May 30, 2017 1:46 pm

But just think about the medical bills for treating snow blindness!

May 30, 2017 11:06 am

Am I missing something or even misinterpreting something? What has UHI got to do with CO2 levels. In line with Warmists’ theories and religion, any such increased local urban Climate Change must be due to higher concentrations of CO2 in urban areas? Is this true! Alternatively this is simply confirmation that the vast majority of any global average temperature rise is due to waste heat emissions and not CO2 emissions! Such emissions occur with all electrical appliances, all engine and boiler operations and exhausts, all other heating systems, all air conditioning system outlets, all manufacturing processes etc. etc. If the latter should we not be prohibiting all these heat generation sources and, presumedly, go back to living in caves, and eating raw food?

Reply to  macawber
May 30, 2017 12:16 pm

no, don’t prohibit them … just manage them and take a small fee (from all) for the management effort and the benefit of all of us. The heat generating fee (after administration expense, of course) is used for mitigation purposes, research, education, and subsidies for non-heat alternatives (like sweaters, hand looms, & llamas).
We need a (U)HI cap and trade & tax & global agreement regulating such.

Reply to  macawber
May 30, 2017 2:07 pm

” … higher concentrations of CO2 in urban areas? Is this true! ” I have done some comparative measurements between diurnal CO2 measurements at my place (close to the shoreline) and the nearest urban centre (in a similar location to the shore line but with far more large buildings and a rising slope). If the obvious places are avoided, eg proximity to vehicular traffic and large a/c vents, there is not a lot of difference. (CO2 makes no difference anyway.) The heat from solar exposed paving and walls will slam into you, but the heat will also produce increased updraft, pulling in a bit of relief in the form of cooler air from the estuary. People get used to this and scuttle through the hot-spots like their counterparts in cold countries react to cold-spots.
The problem with this study is the usual one; people sitting around in temperate climates are not the best people to assess UHI.

Mike Rossander
May 30, 2017 12:23 pm

Again, conclusory statements about productivity that could be easily checked with latitudinal studies. Any UHI effect should also be visible in cities that are already starting with different climates. A 2 degree UHI effect should be indistinguishable from a 2 degree difference due to the cities’ respective latitudes.
This paper alleges that “Higher temperatures damage the economy in a number of ways – more energy is used for cooling, air is more polluted, water quality decreases and workers are less productive, to name a few.” I’ll give them the first one. Yes, cities in the South tend to use more energy for cooling. And to the extent that the increased energy consumption leads to incremental pollution, you may see some addition damages. Evidence (beyond that marginal impact) about air pollution, water quality and worker productivity across latitudes, on the other hand, are pretty much non-existent. Cities in the North and in the South struggle with the same issues.
Finally, businesses are not stupid. If they thought they could get a 12x payback on facilities costs just by repainting the roof, they’d do it in a skinny minute. That would be “free money”. No sales commissions to pay, no new equipment, no risk. It should be an easy sell to any business operating on low margins. The fact that so few businesses have taken any such steps argues rather strongly that the business case for resurfacing is a lot weaker than the author believes.

May 30, 2017 12:36 pm

No doubt that the urban heat island effect is in play in downtown Los Angeles. Curious, following a piece in the LAT’s on the subject of cooling LA as presented here (but seemingly shrilling that the main culprit was climate change (I suspect they mean man-made) and their presentation of how many more days of extreme heat during the summer months would be experienced by certain future time frames, I took a look at the standing records for Los Angeles – for June – August. Interestingly, 25 of the high temperature records still standing are from the late 1800’s – that’s out of 92 days – 27% of them. Records have been kept since 1877, so those 25 days of records, only represent 18% of years in the record. Still standing strong.
More to my point. There would have been no urban heat island effect in the 1800’s in downtown Los Angeles; so in order to tie those records today, with easily 4-6 F on the table because of the effect during our summer months here, would not the measured temps today have to come in 4-6 degrees warmer than the established records?
For example, to break the record of 106, set on Aug 19, 1885, would not we’d have to hit, say 110-112, just to tie it? And, another one to break it. That 106 is still the record high for the entire month of August, BTW.
Should not the temps be adjusted to accommodate what is given as a scientific understanding, even by the EPA?

Jay Turberville
May 30, 2017 2:14 pm

So why have Phoenix, AZ and Las Vegas, NV been some of the fastest growing cities in the past few decades if a hot climate is so poor for productivity and so bad for a city’s economy? Maybe someone will wade through the actual study and see what kinds of things may have been overlooked.

May 30, 2017 2:18 pm

Thanks, Anthony, for highlighting our work.
The Urban Heat Island effect is not controversial.
It is removed from the temperature record when analysing the global climate. It is also omitted from projections of future warming.
However, slightly over half of all people live in cities and well over half of all money is earned there.
Impacts in cities are driven by the sum of global and urban climate change — or rather, there are synergies between the two. Whether you believe that the world will warm because of greenhouse gas emissions or not, the urban heat island effect still has impacts.
There is twist: City leaders can do little about greenhouse gas emissions, as things such as energy taxes are set by national authorities. Mayors around the world are getting all worked up about climate change. If they are serious, the urban heat island effect is actually within their control.

Reply to  (((Richard Tol))) (@RichardTol)
May 30, 2017 4:13 pm

“There is a twist….”
Absolutely, see above at 10:30 a.m..
… a whole new (replacement) area of study. And a whole new regulatory industry.

Gary Pearse
May 30, 2017 3:06 pm

I recall Tol and Mosher a few years ago exchanging mutual admiration posts and pointing out that in the matter of logic, they were the only two on this site that understood what Tol was saying! Ive never thought of RT as a skeptic and I was surprised Steyn engaged him for the court battle with Mann.
Anthony argued that UHI was a growing warming bias in temperature readings and Mosher and NOAA and the choir said, nah, you can leave the thermometers next to AC exhausts, BBQs, jet engine warmups, black asphalt rooves and pavements. It doesn’t change the temperature readings. Anthony even invented a thermometer system for cars to drive through cities from the country and plot their own UHI profiles and these showed the effect rather well. (Have you still got these for sale, Anthony?).
I guess when you have your PhD in temperature mechanics and data tortional wroughting, UHI needn’t be a problem. What troubles me is when we argued natural variation it was rubbished by the tortionists, but, eventually when they needed it, hey, yeah, but that was due to the AMO and PDO hiding in the Gulf of Mexico because of CAGW, or something. When we argued that the warming stopped for 20 years, dozens of climate scientists came down with the Climate Blues, a clinical depression that ended all their careers (they rationalized it in a noble way, but it was clearly дэиуал which is what makes you sick. You’ve wasted your life through graduate school and 30 years of studying fantasy – yeah hard to face). Eventually the tortionists that were about to retire with fat pensions drew straws and we got Karlization of temperatures that blew away the Pause before the rest of the tougher skinned folks came down with CB.
Remember long after the science was settled they had to acknowledge ocean decadal oscillations were even in the picture, record snowfalls and freezing temperatures, endless droughts got copiously rained on, BBQ summers sold out of longjohns, the Ship of Fools got stuck in summer ice (another victim of climate blues: Turney. He came out of the clinic and cried about the thousands of dead Adelie penguins, which later turned out to have died a hundred years ago with no predators to eat them and too cold for the microbes. Haven’t heard from him since, anyone?). They had to call out the climate tortionists and rewrite history a bit, but, hey, we use the same tools for rewriting history and we do the temperature records. Currently the Pause is in and then out, as is the MWP, LIA and other things, depending on if they can be used by the tortionists.
Anyway, I was glad to see UHI back I thought once written out, it was gone – I’m not used to the is Post Normal way of doing things. It complicates the logic for us lesser intellects.

May 30, 2017 3:35 pm

I wonder how that all works? The UHI factor is perfectly “removed” from every disparate UHI area in the world that houses a temperature monitor. These resulting temperatures are then extrapolated to represent all temperatures in the world in order to create the world’s average temperature within a hundredth of a degree with no error bars, (at least none reported by press). Do I have that right?

May 30, 2017 4:07 pm

Wow, now Urban heat islands affect the Climate. We must get rid of those Rural Areas; then Climate Control will be complete!
I’m not worried; the super rats will eat the Urbanites . Problem solved, plenty of food for the Rural dwellers.

May 30, 2017 5:42 pm

‘heat-trapping concrete’
Concrete has a high albedo. Thus reflects sunlight and absorbs less heat than most other surfaces.
And, humidity is more important than temperature changes, of the the magnitude we are talking about, to energy consumption, productivity, etc.
Having lived in hot humid and hot dry climates. I can assure you that when temperatures are around 30C in a hot humid climate you will run you airconditioner. Whereas at the same temperature in a dry climate you wouldn’t dream of turning on your airconditioner.
The relevance of this, is that many of the steps taken to ‘cool’ urban areas, increase humidity. The main exception is high albedo roofs for buildings. If you look at Perth, Australia on Google Earth, you will see that large numbers of buildings have what appear to be white roofs. In fact, the roofs are highly reflective steel. They appear white because of how much sunlight they reflect.

May 30, 2017 6:38 pm

Or you can just wash down the roads and let evaporation take care of the rest and we get clean roads.

May 30, 2017 7:14 pm

Simple question. How does CO2 cause the Heat Island Effect? CO2 has nothing to do with the heat island effect. Turning cool grass into extreme heat sinks like asphalt and concrete have nothing to do with CO2.

Reply to  co2islife
May 30, 2017 9:51 pm

“How does CO2 cause the Heat Island Effect?” It does not.

Dr. S. Jeevananda Reddy
May 30, 2017 8:59 pm

I discussed UHI factor under Chapter 7 – Ecological Changes in my book “Climate Change: Myths & Realities” in 2008. In this book on page opposite to page 113 the same figure presented in the present article on UHI. In this chapter also presented urban growth along with a aerial photo “a Summer in the City” of downtown Sacramento in 1998 [Published in a daily newspaper] along with rate of heat island growth in some US cities.
Dr. S. Jeevananda Reddy

Mickey Reno
Reply to  Dr. S. Jeevananda Reddy
May 31, 2017 8:18 am

Many urban centers will benefit from net heating in the reduction of heating costs in winter. Of course, in warmer latitudes, air conditioning costs will drive up overall energy demand, and more importantly, peak demand.
I’ve always thought the very best use of solar would be to use it in a specific way to air condition buildings in hot climates, thereby reducing peak demand on electricity grids in those places.
Here’s the Lovin’ Spoonful’s best song:

May 31, 2017 1:22 am

Prof Tol makes a fundamentally valid point that as a practical matter, steps to cool urban areas will have more direct impact on the climate most people live in, than steps to control GHGs. As I referred to above, in the ‘hot’ city of Perth, Australia, people are cooling buildings with high albedo roofs.
It’s interesting to note that, while Australia spends vast amounts on climate policies, the installation of high albedo roofs, has been entirely due to individual choices, without government subsidies or intervention. Where I live in an older area of Perth, high albedo roofs on homes has gone from almost none 30 years ago, to about 50% today.

Reply to  Philip Bradley
May 31, 2017 4:52 am

That’s right, Philip. If you’re worried about global warming, then you should be worried about local warming too. It’s much easier to do something about local warming.

May 31, 2017 4:51 am

i.e., Urban heat island effect is far more important than global warming.

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