Urban heat island features of southeast Australian towns
This review of the above paper is from
www.co2science.org see links page.
The 13 pages can be read or downloaded below, each page gif file
is from 90 to 135 Kb.
Update 27, June. 216KB pdf
Link to Urban heat island features of southeast
Australian towns
Reference
Torok, S.J., Morris, C.J.G., Skinner, C. and Plummer, N.
2001. Urban heat island features of southeast
Australian towns. Australian Meteorological Magazine 50:
1-13.
What was done
The authors studied the characteristics of urban heat islands in
several cities in Australia with populations ranging from
approximately 1,000 to 3,000,000 people.
What was learned
The maximum urban-rural temperature differences of the Australian
cities were found to scale linearly with the logarithms of their
populations. The authors noted that the same was true for cities
in Europe and North America, but that the heat islands of
Australian cities were generally less than those of similar size
European cities (which were less than similar size North American
cities) and that they increased at a slower rate with population
growth than did European cities (which increased slower than did
cities in North America). The regression lines of all three
continents essentially converged in the vicinity of a population
of 1,000 people, however, where the mean urban-rural temperature
difference was approximately 2.2 ± 0.2 °C.
What it means
The results of this study suggest that very small towns, with
populations measured in mere hundreds of inhabitants, likely have
urban heat islands that are on the order of the entire amount of
global warming that is believed to have occurred since the end of
the Little Ice Age. With such small aggregations of people
having such a dramatic impact on air temperature, it is ludicrous
to believe that on top of the natural warming experienced by the
earth in recovering from the Little Ice Age we can confidently
discern an even more subtle increase in background temperature
caused by concomitant increases in greenhouse gas
concentrations. Changes in population, which have generally
been positive nearly everywhere in the world over this period,
could easily explain whatever tiny bit of warming is left after
the natural component of warming (which must be substantial,
relatively speaking) is subtracted from the total amount of
warming recorded by the totality of earth's thermometers over the
past century or so.
Additional comment by Warwick Hughes
Those few of us greenhouse sceptics who understand global
temperature records will be gratified that 95 years after
the formation of the Australian Bureau of Meteorology (BoM) they
have acknowledged the existence of the urban heat island (UHI) in
very small towns of ~1000 population. Possibly prompted by
the PhD research carried out by Christopher J.G. Morris.
We live in hope that the BoM might discover and publish the
extent that UHI bias has contaminated century long temperature
trends in Australia.
This is a good point at which to remember that the USA climate research team that put together the GHCN set their rural cut-off at 10,000. This can now be seen for what it is, a ridiculously high figure that has ensured that much UHI bias remains in the "Rural" series of the GHCN.
To read the full paper work your way down these links use your Back button between pages.
Posted 12, June, 2002
