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Yes it's been talked about extensively even in the public for over a decade at least. In blogs and comment fields and columns the "but it's just the urban heat

Yes it's been talked about extensively even in the public for over a decade at least. In blogs and comment fields and columns the "but it's just the urban heat island" is a common myth that pops up all the time and has to be debunked constantly. Some GISS temperature data for example excludes urban stations. Classification by night lights in satellite images. These rural stations also show similar trends. More at the ever resourceful myth-collecting Skeptical Science site. http://www.skepticalscience.com/urban-heat-island-effect.htm http://www.skepticalscience.com/urban-heat-island-effect.htm

nkurz 13y ago
I'm in danger of doing it also, but I think you are reacting defensively to a valid specific question because of your views on the larger climate reality. There is definitely an effect on individual stations as a result of changes to their surrounding environment. The question is whether the corrections applied to correct for it significantly affect the results of any given analysis. In this particular case, they are using GHCN Daily data that does not include any correction for this effect: http://www.ncdc.noaa.gov/oa/climate/ghcn-daily/index.php?name=bias http://www.ncdc.noaa.gov/oa/climate/ghcn-daily/index.php?nam... The GHCN Monthly data does include such corrections: https://www.ncdc.noaa.gov/ghcnm/v3.php?asection=homogeneity_adjustment https://www.ncdc.noaa.gov/ghcnm/v3.php?asection=homogeneity_... The magnitude of the changes made are quite large compared to the effects being measured. They average to zero, but are bimodal centered around about +1F and -1F: ftp://ftp.ncdc.noaa.gov/pub/data/ghcn/v3/techreports/Technical%20Report%20NCDC%20No12-02-3.2.0-29Aug12.pdf I think it's a brilliant visualization, but if we are to presume the corrections are necessary and correct, it would also be reasonable to question what conclusions can be drawn from an analysis of data that does not include such corrections. At the least, I think it would be interesting to see their analysis applied to the more rural CRN1 and CRN2 stations versus the majority of lower quality CRN3, CRN4, and CRN5 stations that make up the bulk of the readings.
- Gravityloss 13y ago
  Yes, you are correct. I was reacting defensively. If you want to draw more conclusions, then you want different analysis anyway. For anyone interested in playing a little with the global data in a very easy way, check out woodfortrees.org: http://woodfortrees.org/plot/gistemp-dts/from:1960/mean:12/plot/rss/mean:12/plot/uah/mean:12/plot/best/from:1960/mean:12 http://woodfortrees.org/plot/gistemp-dts/from:1960/mean:12/p...

nkurz 13y ago

I'm in danger of doing it also, but I think you are reacting defensively to a valid specific question because of your views on the larger climate reality. There is definitely an effect on individual stations as a result of changes to their surrounding environment. The question is whether the corrections applied to correct for it significantly affect the results of any given analysis. In this particular case, they are using GHCN Daily data that does not include any correction for this effect: http://www.ncdc.noaa.gov/oa/climate/ghcn-daily/index.php?name=bias http://www.ncdc.noaa.gov/oa/climate/ghcn-daily/index.php?nam... The GHCN Monthly data does include such corrections: https://www.ncdc.noaa.gov/ghcnm/v3.php?asection=homogeneity_adjustment https://www.ncdc.noaa.gov/ghcnm/v3.php?asection=homogeneity_... The magnitude of the changes made are quite large compared to the effects being measured. They average to zero, but are bimodal centered around about +1F and -1F: ftp://ftp.ncdc.noaa.gov/pub/data/ghcn/v3/techreports/Technical%20Report%20NCDC%20No12-02-3.2.0-29Aug12.pdf I think it's a brilliant visualization, but if we are to presume the corrections are necessary and correct, it would also be reasonable to question what conclusions can be drawn from an analysis of data that does not include such corrections. At the least, I think it would be interesting to see their analysis applied to the more rural CRN1 and CRN2 stations versus the majority of lower quality CRN3, CRN4, and CRN5 stations that make up the bulk of the readings.

Gravityloss 13y ago
Yes, you are correct. I was reacting defensively. If you want to draw more conclusions, then you want different analysis anyway. For anyone interested in playing a little with the global data in a very easy way, check out woodfortrees.org: http://woodfortrees.org/plot/gistemp-dts/from:1960/mean:12/plot/rss/mean:12/plot/uah/mean:12/plot/best/from:1960/mean:12 http://woodfortrees.org/plot/gistemp-dts/from:1960/mean:12/p...