The Berkeley conclusions
about the urban heat effect were nicely explained by Andy Skuce in an SkS post in 2011.
He claims, presumably relying on the increasingly absurd McKitrick and McIntyre, that «the hockey stick [showing rapidly rising temperatures over the last 100 years] is broken», and then goes on to recycle long - exploded claims
about urban heat islands and satellite data, all of which have been addressed in detail on this blog.
But what
about the urban heat island effect around major cities like Babylon and Alexandria?
We have known
about the Urban Heat Island effect for years.
The state of knowledge
about urban heat islands around 1980 is described and work since then is assessed in terms of similarities to and contrasts with that situation.
It isn't always
about urban heat from humans.
This data could even be used to educate the community
about the urban heat island effect, weather, and climate.
There are too many potential sources of bias which are not accounted for, too many apples - to - oranges comparisons, and they can not draw any conclusions
about urban heat influences until their data are homogenized and other non-climate influences are removed.
Fortunately McIntyre has acknowledged that TOB must be considered in their analysis, as has Watts, which is a good start, but they must also account for the other biases noted above in order to draw any valid conclusions
about urban heat influences.
So no need to appeal to the usual, debunked «skeptic» talking points
about urban heat island effects and the like, in order to explain lack of amplification over land.
Not
about urban heat effect, alone.
Other important issues — Dan might be able to say more
about urban heat islands, and how they might grow in the future, and be exacerbated by possible large temperature increases.
Why is it that climate sceptics have been going on
about the Urban Heat Island * being the cause of the observed temperaure increase found in the global averages, if, as you say, there is no increase in the global averages?
Not exact matches
Much less is known
about the impact of environmental and psychological exposures, but some potential threats include: • Air pollution: A small study of 60 newborns in New York City found that expectant mothers» exposure to combustion - related
urban air pollution — emissions from cars, trucks, residential
heating, power generation and tobacco smoking — may alter the structure of chromosomes in their fetuses.
U.S. Department of Agriculture scientists grew weeds in three sites: an organic farm in western Maryland, a park in a suburb of Baltimore, and in downtown Baltimore, which is choked with smog and
about 3 to 4 degrees warmer than the surrounding countryside because of the
urban heat island effect.
Increasing levels of ozone, in turn, trap more
heat, exacerbating the
urban heat island effect: Cities are normally
about five to 10 degrees hotter than surrounding suburbs because asphalt and cement absorb sunlight, generating a vicious cycle of escalating pollution and
heat.
It's not
about someone saying there is
urban heat bias, it's
about the method of modeling used to model the observations which reduces the error extent.
Back in ’88 there was still quite a debate
about whether the world was in fact warming or whether the temperature record had been contaminated by the
urban heat island effect of cities springing up around former rural weather stations.
Well, while I'm waiting for the reams of evidence of AGW to come in, I thought I'd write
about UHI (
Urban Heat Islands) and global average tempertures.
To add to the confusion, «
about 90 percent of the land - based data now being used to construct global averages are sampled in cities,» contaminating readings with an «
urban heat island» effect.
I see you wrote 6 paragraphs
about your supposed climate «skepticism» arising from the
urban heat island effect, but I see not a single word of explanation
about why the UHI effect would turn a non-warming trend into a warming trend.
Bindidon It's not surprising that you give the fully discredited (because of data manipulations and the
urban heat island effects) GISS Surface Temperature to support your fallacious point
about it being hotter now than in the»30s.
The
Urban Heat Island Effect Has Hopelessly Corrupted the Land Thermometer Data... substantial average UHI warming occurs even at low population densities,
about ~ 1 deg.
When you start to read
about the work Watts and others have done given the
Urban Heat Island effect and the siting of stations confidence in what is reported is very low.
And don't get me started
about «
urban heat islands» and the benefits of green roofs.
«We evaluate to what extent the temperature rise in the past 100 years was a trend or a natural fluctuation and analyze 2249 worldwide monthly temperature records from GISS (NASA) with the 100 - year period covering 1906 - 2005 and the two 50 - year periods from 1906 to 1955 and 1956 to 2005... The data document a strong
urban heat island eff ect (UHI) and a warming with increasing station elevation...
About a quarter of all the records for the 100 - year period show a fall in temperatures... that the observed temperature records are a combination of long - term correlated records with an additional trend, which is caused for instance by anthropogenic CO2, the UHI or other forcings... As a result, the probabilities that the observed temperature series are natural have values roughly between 40 % and 90 %, depending on the stations characteristics and the periods considered.»
Oke (1973 and Torok et al (2001) show that even towns with populations of 1000 people have
urban heating of
about 2.2 C compared to the nearby rural countryside.
How to move beyond the warm words
about tackling
urban heat islands to doing something
about them.
Oke et al 1991 is a companion study that is much more informative
about UHI, with interesting discussions of the contributions to UHI of canyon view, thermal storage, anthropogenic
heat emissions, an
urban greenhouse effect from additional pollution and moisture, surface emissivity etc..
Anthony Watts (et al) currently have a paper in review that does in fact contain evidence that the
Urban Heat Island Effect has exaggerated the amount of warming in the surface temperature measurements — refer New study shows half of the global warming in the USA is artificial If he is right
about the U.S.A, then the surface measurements for the rest of the world should be questioned as well.
Let me explain, the
urban heat island effect is not what I was on
about.
For example, McKitrick and Michaels claimed in 2007 that
about half of the recent warming over land is due to
urban heat island effect, although this result was disputed by Schmidt in 2009.
I'd give it better than 50 - 50 that talking
about surface temperature without at least a footnote to UHI — the
Urban Heat Island effect — says a lot more
about the lack of integrity of modern climate research that anything else.
In January 2012, climate researcher Trevor Prowse put questions to the Bureau of Meteorology
about the results charted above, making the point that as the 14 tidal stations are mostly free of
urban heat effect, all are at sea level and are well scattered around Australia, they may be more accurate than any other land - based data.
These stations are scattered around Australia, all are at sea level and are said to be isolated from
Urban Heat Influence - although the satellite images below suggest that questions might be asked about heat from nearby industrial and urban development, dependent upon prevailing w
Urban Heat Influence - although the satellite images below suggest that questions might be asked about heat from nearby industrial and urban development, dependent upon prevailing wi
Heat Influence - although the satellite images below suggest that questions might be asked
about heat from nearby industrial and urban development, dependent upon prevailing wi
heat from nearby industrial and
urban development, dependent upon prevailing w
urban development, dependent upon prevailing winds.
So it's good news indeed that Louisville, in decidedly red - state Kentucky, is getting serious
about tackling its
urban heat island effect through increased
urban forestry, as well as efforts to promote reflective surfaces and green roofs.
If they get you in trouble, invoke the hockey stick or
urban heat island or start complaining
about how nasty they are.
FAIL The nonclimatic effects they are talking
about are
Urban Heat island trends caused by «socioeconomic determinants of surface processes and data inhomogeneities.»
But a fine statistical analysis showed the
urban heat effect could not explain a global temperature increase of
about 1C since 1950.
4.4 Anthropogenic impact studies
about direct human influence like
urban heat island and land use changes (eg — not
about GHG emissions)
[T] he
urban heat effect could not explain a global temperature increase of
about 1C since 1950.
The 0.10 ± 0.06 °C rise due to
urban heat advection corresponds to
about 10 % of the observed temperature rise of
about 1.0 °C in the last century.