Urban Heat Island Myth is Dead

Thu, 2010-01-21 18:37Mitchell Anderson
Mitchell Anderson's picture

Urban Heat Island Myth is Dead

Another climate change denier myth - this one a favorite of Anthony Watts and his Watts Up With That” blog - has just bit the dust.

Many skeptics for years have sought to explain away decades of climate research by showing slides of weather station thermometers sited next to heating vents or surrounded by asphalt.

This much-touted “urban heat island effect” was supposed to trump all those fancy graphs and equations that egghead scientists were fixated on. Except it’s not true.

A recent peer-reviewed paper in the Journal of Geophysical Research looked at data from 114 weather stations from across the US over the last twenty years and compared measurements from locations that were well sited and those that weren’t.

They did find an overall bias, but it was towards cooling rather warming.

According to the authors,

the bias is counter intuitive to photographic documentation of poor exposure because associated instrument changes have led to an artificial negative (“cool”) bias in maximum temperatures and only a slight positive (“warm”) bias in minimum temperatures.”


This is latest in an expanding body of science that has looked at the urban heat island effect in excruciating detail and found nothing to undermine the observed and disturbing warming in the US over the last several decades.

The IPCC found that: Over the Northern Hemisphere land areas where urban heat islands are most apparent, both the trends of lower-tropospheric temperature and surface air temperature show no significant differences. In fact, the lower-tropospheric temperatures warm at a slightly greater rate over North America (about 0.28°C/decade using satellite data) than do the surface temperatures (0.27°C/decade), although again the difference is not statistically significant.

Another paper in Climate Change in 2007 stated: Studies that have looked at hemispheric and global scales conclude that any urban-related trend is an order of magnitude smaller than decadal and longer time-scale trends evident in the series (e.g., Jones et al., 1990; Peterson et al., 1999)…Thus, the global land warming trend discussed is very unlikely to be influenced significantly by increasing urbanization (Parker, 2006).

While such dense scientific prose is not as photogenic as a picture of a weather station in a parking lot, the fact is that science has thoroughly picked over this red herring.

This myth is now officially busted. 




Either way - the damage is done because optics count. If you set a thermometer next to an artificial heat source and then successfully adjust the data, you still look dumb for putting a thermometer next to a heat source in the first place.

Busted, but they'll keep saying it. They know they're lying, but they know they'll fool some people.

Umm...just stand in the middle ashpalt parking lot on a hot sunny day...duh

The study confirms that many sites are poorly sited; nearly 85% of them by USCRN standards. And at the end of the study, they actually thank Anthony Watts.

"The authors wish to thank Anthony Watts and the many volunteers at
surfacestations.org for their considerable efforts in documenting the current site characteristics of USHCN stations."

Why documenting sloppy weather sites and poor documentation of instrumentation and other changes qualifies one as a "denier" is beyond me. It is something professional climate scientists should have done years ago without the prodding of Anthony Watts.

Seems to me that Mr. Watts and his amateur cohorts have helped improve the quality of weather station data.

Watts is classified as a denier, because he drew unsupported claims from his surfacestations project. Repeatedly he claimed that the poor siting resulted in a warm bias, without ever doing the analysis. Whenever someone did, they found his claims of a warm bias were untrue. He was told so several times, but he (and his supporters, including one Roger Pielke Sr) kept on making an unsupported claim in favor of the actual data analysis.

Watts and his amateur cohorts thus have not helped improve the quality of weather stations. They clearly are fine already.

Well, we can hope, I suppose.

But experience has shown over and over again that the denialsphere is an alternate limbo reality full of undead zombie arguments and talking points.

Yup. Like Monty Python's parrot, it's not dead, It's resting.

I'm a skeptic.

What does that mean?
This is basically what a skeptic claims; I'm right and here is the evidence to support my claim.
On the other hand a denier claims; I'm right and your wrong, listen only to me or others just like me. Inference rather than evidence is all that is needed to support a deniers claim.

Sorry about the rant, I just think that sometimes people confuse skeptics for deniers and then they're both "frowned" upon.

As a skeptic, I am always looking for evidence to support the claims I make, as well as claims other people make. I never simply "believe" what I'm told. I want proof!

This is evident in the report that has been published in the peer reviewed Journal of Geophysical Review. Every one involved in the study was skeptical of the claims made by deniers who, simply by inference, claimed that the temperatures would be higher than they should have been.

In fact, they where completely wrong. If they had engaged in some good old fashioned science, instead of the mental exercise of making stuff up, then they would have saved themselves the embarrassment and humiliation of being wrong again.

Hey deniers, next time ignore the pseudo-science crap and practice real science.

I can't wait to see what kind of backpedaling this will case amongst the deniers.


What's the problem guys, don't like this? Seems to squash this premise to me.

It's quite hilarious to see Pielke Sr complain about "professional discourtesy", when Anthony Watts has had plenty of chances to do the analysis himself, but instead decided to claim a warm bias without doing the number crunching. How "professional" is claiming something that the data does not?

Besides that, Watts has been so 'stupid' to publish his data. With the demand that all data is freely available to anyone, why is it that it suddenly is a problem here that this data is used, with appropriate reference?

Ah, that's right, it's the deniosphere that is now caught in its own web. WAAAAAAA! SCREEEEAAAAAMMMM!


I don't know what you mean by, "Seems to squash this premise to me."

This is nothing more than a denier who got "caught with his pants down" and now he has cried fowl in an attempt to save face while he hurriedly writes a paper to "refute" this paper.

His attempt to include a credible scientific agency in his paper is simply fake.

Do you really believe that a denier who releases a "scientific" paper denying a scientific claim, consults with the scientists he is about to call liars?

I don't think so.

There is no UHI or microclimet influence on temperature over the oceasn which cover 70% of the earth's surface. Temperature trends over these regions are very similar to those over land. Watts and co. never had a case.

"A rising tide lifts all boats."

The tide is increasing GHGs. A no brainer.


I tried to read the linked paper but Adobe says the file is damaged and could not be repaired. Sort of the like the original data I guess. The deeper point is, the fanatics won't even investigate the critical claims until a skeptic makes them. And the fact that no bias was detected is probably an indication that the data were too unreliable to begin with.

How an urban setting could NOT create a bias is a mystery to me. Does the unavailable paper say it had already been taken into account, or that there is no such thing as urban heating? Sounds ridiculous. And why don't you fix your link? --AGF

How can this article claim that the urban heat island effect is a myth?? It has been shown by many different methods in many different places and by many different researchers.
The existence of UHI is scientific fact.
A few methodological issues with an out-of-date study by one researcher does not mean that all the others conducted properly are also flawed! Nor does it mean that the study in question is entirely false.

Scott, you seem to misunderstand the issues of urban heat island effect and are focussing on something entirely unrelated.

Anonymous, the denialist myth is that the rising US surface temperature measurements are misleading because so many of them are taken from places that have become more urban over time.

In fact, objective analysis has repeated shown that the well-accepted Urban Heat Island effect has been slightly over-corrected.

Perhaps the denialists knew this would be the likely outcome of a reexamination. Is this why they delayed proving their claim and instead shouted about "discourtesy" and waved amateur photographs of particular weather stations?

The believers have a marked tendency to concentrate on the trivial and irrelevant. Sea surface temp is far more relevant than land temps. And the great bugbear of sea level rise continues to disappoint the informed faithful. It insists on a snail's pace of 3mm/year, and holds steady on a decadal scale (it's going down at the moment). Yet this steady, foot per century rise is translated into catastrophe by the non-deniers. And they wonder why we don't respect their intelligence.


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