The author's points on non-linearity and time delays are actually more relevant to the discussion in other presentations when I talked about whether the climate models that show high future sensitivities to CO2 are consistent with past history, particularly if warming in the surface temperature record is exaggerated
by urban biases.
Not exact matches
We carefully studied issues raised
by skeptics:
biases from
urban heating (we duplicated our results using rural data alone), from data selection (prior groups selected fewer than 20 percent of the available temperature stations; we used virtually 100 percent), from poor station quality (we separately analyzed good stations and poor ones) and from human intervention and data adjustment (our work is completely automated and hands - off).
They specifically wanted to answer the question is «the temperature rise on land improperly affected
by the four key
biases (station quality, homogenization,
urban heat island, and station selection)?»
New efforts aim to head off teacher
biases by running preservice students through simulations or embedding them in
urban neighborhoods.
http://theatln.tc/2www9HF The
Urban - School Stigma: Influenced by biases against urban education, parents are moving away from city schools and contributing to segregation in the pr
Urban - School Stigma: Influenced
by biases against
urban education, parents are moving away from city schools and contributing to segregation in the pr
urban education, parents are moving away from city schools and contributing to segregation in the process
Regarding national findings, a review of the CREDO study
by the National Education Policy Center questioned CREDO's statistical methods: for example, the study excluded public schools that do NOT send students to charters, thus «introducing a
bias against the best
urban public schools.»
Human induced trend has two components, namely (a) greenhouse effect [this includes global and local / regional component] and (b) non-greenhouse effect [local / regional component]-- according to IPCC (a) is more than half of global average temperature anomaly wherein it also includes component of volcanic activities, etc that comes under greenhouse effect; and (b) contribution is less than half — ecological changes component but this is
biased positive side
by urban - heat - island effect component as the met network are concentrated in
urban areas and rural - cold - island effect is
biased negative side as the met stations are sparsely distributed though rural area is more than double to
urban area.
However, the actual claim of IPCC is that the effects of
urban heat islands effects are likely small in the gridded temperature products (such as produced
by GISS and Climate Research Unit (CRU)-RRB- because of efforts to correct for those
biases.
Timothy Chase writes in 142: Of course contrarians will point out that instruments at poorer sites will have a
bias, but as tamino (# 91) points out, this
bias is corrected for, and it is quite possible that given the methodology employed, removing the
urban sites would actually result in a higher average temperature, and as Hansen points out (see tamino's first reference in # 93), the
bias introduced
by urban sites is quite negligible.
I don't see why the large - scale systematic
urban bias issue isn't best addressed
by an estimate in the style of McKittrick — looking for residual correlation between regional economic activity and regional temperature anomaly — even for those who object to the specific implementation in that paper.
This is plagued
by subjective, manual adjustments that in many cases can not be justified, sites with years of missing data, sites that should not have been used because of
Urban contamination, and a large warming
bias.
If an
urban station is much more affected
by urbanization than its neighbours, then this process will reduce the
bias to better match the neighbours... So far, so good.
A global - scale instrumental temperature record that has not been contaminated
by (a) artificial
urban heat (asphalt, machines, industrial waste heat, etc.), (b) ocean - air affected
biases (detailed herein), or (c) artificial adjustments to past data that uniformly serve to cool the past and warm the present... is now available.
Well, if you look at the bottom panels of Figure 32, you can see that most of the neighbours the program used are
urban stations, i.e., the neighbours are also affected
by urbanization
bias.
We carefully studied issues raised
by skeptics:
biases from
urban heating (we duplicated our results using rural data alone), from data selection (prior groups selected fewer than 20 percent of the available temperature stations; we used virtually 100 percent), from poor station quality (we separately analyzed good stations and poor ones) and from human intervention and data adjustment (our work is completely automated and hands - off).
It is the data that is most greatly affected
by the most contentious issues: data selection
bias,
urban heat island, and station integrity issues.
The selections of stations made for GSN
by Peterson, T.C., Daan, H. and Jones, P.D (1997), and for global monitoring and trend estimation
by Jones and Moberg (2003) cited above were carefully made to avoid severe
urban biases.
By the way, think about what these adjustments mean — adjusting recent temperatures down means that our growing
urban society and hot cities are somehow introducing a recent cooling
bias in measurement.
In addition, he is correcting the data for
urban heat
bias by the so - called population density adjustment.
Michaels and McKitrick found what nearly every sane observer of surface temperature measurement has known for years: That surface temperature readings are
biased by urban growth.
And while some warming delusionists have tried to claim
biases associated with
urban heat islands (the most recent effort, led
by Anthony Watts, was a total fizzle) an IPCC admission that the planet had only warmed half as much as we thought would be a big story indeed.
2) Some stations must be
biased warm
by urban heat islands, but their influence on the global trend can't be detected with any of the techniques available for separating
urban and non-
urban stations.
Berkeley Earth also has carefully studied issues raised
by skeptics, such as possible
biases from
urban heating, data selection, poor station quality, and data adjustment.
The range of the gradient is 12 kilometers (grid 12 km
by 12 km) and its purpose is to show whether or not accurate and meaningful C12 / C14 measurements can be made anywhere near a powerplant (for instance) without introducing the same
bias as, say, an «
urban heat island».
They specifically wanted to answer the question is «the temperature rise on land improperly affected
by the four key
biases (station quality, homogenization,
urban heat island, and station selection)?»