reply to post by PuterMan
Regarding your reply to my point about lack of Antartic weather stations, by noting expeditions to the region, you appear to fail to realize that
expeditions do not make for weather stations. Yes, they took temp. measurements, but they didn't do it on a regular basis at the same place, year in
and year out. There were likely some whaling stations in the Antartic ocean, which would make for regular observations, but expeditions don't cut
it; they're to ephemeral.
And Antartic stations are but one component of what I brought up regarding the difference in observation sampling points between now and back then.
What about floating weather buoys and satellite observations over large portions of the earth, i.e. the oceans, which it was not possible to get
static, regular temperature measurements? Again, I'm guessing that the historical average temperatures are corrected for this to make them
consistent with current observed average temperatures.
As for belittling models, citing your programming experience, if you know anything about science, everything is model based. And yes models can make
bad predictions or get fed bad data, but models can also be very powerful at predicting things. To just say models are bad and can introduce errors
is not a compelling argument.
Also your response to my point about correcting for the fact that ice sheets are now much smaller compared to 1880 seems to miss the point. I would
imagine IF such a correction is used, it is done for regions of the earth for which there were regular (by this I mean consistent, time-wise and
location-wise) measurements back then, i.e. the oceans and the Antartic. I don't claim to be knowledgeable in this field, so I don't know if such
modeling corrections are made or not, but I can conceive of why they may be introduced in order to count for poor spatial distribution of weather
stations back in the day. Yes, we have data from back then, but not nearly as much, so such extrapolations may be necessary.
Back to the satellite temperature imaging issue for a moment: I believe that sometime in the last 10-15 years there was some paradigm shift in what
was believed to be the best estimate of the global average temperature and this had to do with measuring the temperature of the ocean via satellite
imagery; furthermore, I believed this changed the absolute value of global temp averages. If this is indeed so, then there would be corrections made
to data before such measurements were possible, based on the difference between contemporary conventional temp. measurements and these satellite
You seem to know where the data is, but not to know precisely how this global temperature average is determined. I don't mean this as a dig at you,
but rather to suggest that you ought to look into this aspect of the matter further to see if there are such changes in technique that would give rise
to these small changes in the data set over time. Rather than contacting the climate blog, how about checking with whatever agency/institution
generates/maintains the dataset?
A few questions about your OP:
Also I am confused about your dates, your post's title and throughout it you refer to 1880, but then you talk about using a data set for the base
period 1951-1980. Is there a typo here?
Additionally, in the lowest most plot in your OP, what are the units for the vertical axis, 0.01 C? I infer this to be the case.
Finally, keep in mind that these data set changes are on the order of 0.06 degrees C and the observed temperature difference over the period of 1880
to 2005 is about 0.9 degrees, so you are talking about a 1/15th difference or systematic error of less than 7%, which isn't insignificant but the
trend/signal is still much larger than this, which means it is statistically significant. And keep in mind, this "error"/change in these data maybe
because of more accurate corrections such as the one I suggested involving improved global temp. estimates from satellite imagery.
And yes, governments are entirely capable of suppressing reports and data and not allowing certain studies to be conducted. And sure, scientists are
also capable of manipulating data, but what is in it for them to do so in this case? Governments are definitely influenced by business, in particular
the petroleum sector. But are you claiming that all or the vast majority of the scientists in the climate field are in cahoots with
environmentalists? That's an extremely doubtful proposition.
Thanks for taking the time and making the effort to respond to my previous post.