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Just to comment on a couple of other points mentioned earlier on this thread....
Do they? Klotzbach et al: http://pielkeclimatesci.files.wordpress.com/2009/11/r-345.pdf
5. Conclusions
[39] We find that there have, in general, been larger linear
trends in surface temperature data sets such as the NCDC
and HadCRUTv3 surface data sets when compared with the
UAH and RSS lower-tropospheric data sets, especially over
land areas. This variation in trends is also confirmed by the
larger temperature anomalies that have been reported for near
surface air temperatures [e.g., Zorita et al., 2008; Chase et al.,
2006, 2008; Connolley, 2008]. The differences between
surface and satellite data sets tend to be largest over land
areas, indicating that there may still be some contamination
because of various aspects of land surface change, atmospheric
aerosols and the tendency of shallow boundary layers
to warm at a greater rate [Esau, 2008; Christy et al., 2009].
Which brings us back to the UHIE...
How, exactly, is that accounted for? Do they just knock off a percentage to compensate? Or maybe it's a complicated formula? When a Finnish climate scientist kept asking Phil Jones at CRU for details of what calculations he used to account for this, Jones repeatedly ignored him. There's a surprise.
It must be very difficult to work out for every location and over time as an urban area is developed. An airport for instance, 40 years ago may have just 20 flights a day using one runway, now maybe 100 flights a day on two runways with bigger planes. Or a station by a quiet road which over time becomes much busier with traffic. Wind factors. There are so many variables. So if you have the details of how they account for it, I would be interested to see it.
Like this sort of thing: Melbourne Temperature Hottest in 100 Years
Melbourne, as a city, has grown enormously over the past 50 years. So it wouldn't be that surprising if a weather station in the middle, now surrounded by ever taller buildings that helps to retain heat better, is going to give a warmer reading. But is that 93 degrees a straight thermometer reading or has it been adjusted (accounted for)? If this is not UHI effect, why weren't there record breaking temps outside of Melbourne? http://www.warwickhughes.com/blog/?p=463
Surface temperature records are valuable in the long term, but wouldn't it be better to only use weather stations that aren't affected by UHI. Which is strange given the GISS and NOAA have dropped most of the rural station data and now only use, in California for example, only 4 stations, 3 in LA and one SF airport.
Is it that difficult to see why some people might become sceptical? |
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