Meer bebouwing = meer warmte
maar...
broeikaseffect is niet stadseffect.
Ten eerste wordt daarvoor gecompenseerd en ten tweede heb ik anders Atlantis gevonden, want de oceanen warmen sterk op.
Verdere uitleg op website van Coby Beck:
Warming Due to Urban Heat Island Effect
(Part of the How to Talk to a Climate Sceptic guide)
Objection:
The apparent rise of global average temperatures is actually an illusion due to the urbanization of land around weather stations, the Urban Heat Island effect.
This is a real favorite of the die hards. It is actually a perfectly reasonable idea, but what is not reasonable is believing it is real with no evidence for it whatsoever. And what is worse is presenting it as something that either the climate science community has never thought of or something they purposely ignore when in fact it has been well studied and simply found to be negligible.
Answer:
Urban Heat Island Effect has been examined quite thoroughly and simply found to be negligible. Real Climate has a detailed discussion of this here. What's more, NASA GISS takes explicit steps in their analysis to remove any such signal by normalizing urban station data to the surrounding rural stations.
But heavy duty data analysis and statistical processing aside, a little common sense and a couple of pertinent images should put this idea to bed.
1. http://antwrp.gsfc.nasa.gov/apod/ap040822.html
2. http://data.giss.nasa.gov/gistemp/2005/
Image one is a view of the entire surface of the earth as seen at night from satellites. Aside from being very beautiful, it is a perfect indicator of urbanization on earth. As you can see, the greatest urbanization is over the continental United States, Europe, India, Japan, Eastern China and generally coastal South America.
The right half of the feature image in the second link is a global surface temperature anomaly map. Look at North America, look at Europe, at Asia, Australia, Africa and the Poles. There is quite simply no way to discern any correlation whatsoever between urbanization and warming.
"Global Warming is an artifact of Urban Heat Island Effect" is an artifact of Urban Myth Effect.
Wikipedia has a good article on this subject. Among all the interesting details it mentions a few papers that discuss efforts to identify and quantify UHI influences on the global temperature trend including this one which would be a good one to cite:
A 2003 paper ("Assessment of urban versus rural in situ surface temperatures in the contiguous United States: No difference found"; J climate; Peterson; 2003) indicates that the effects of the urban heat island may have been overstated, finding that "Contrary to generally accepted wisdom, no statistically significant impact of urbanization could be found in annual temperatures." This was done by using satellite-based night-light detection of urban areas, and more thorough homogenisation of the time series (with corrections, for example, for the tendency of surrounding rural stations to be slightly higher, and thus cooler, than urban areas). As the paper says, if its conclusion is accepted, then it is necessary to "unravel the mystery of how a global temperature time series created partly from urban in situ stations could show no contamination from urban warming." The main conclusion is that micro- and local-scale impacts dominate the meso-scale impact of the urban heat island: many sections of towns may be warmer than rural sites, but meteorological observations are likely to be made in park "cool islands."
If necesary, be sure to refer to all the other ways we know that the global warming trend is not an artifact of anything, it is real.
Groeten,
Wouter
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