lee wrote on Nov 9^th, 2019 at 4:55pm:


lee up to his old trick of demanding answers to his questions to divert the fact that the onus of evidence is on him.

As you would expect, scientists have done lots of studies on Stevenson screens. This is to be expected as the screens will no doubt have changed over the 130 odd years of records and over the thousands of locations. The Stevenson screens are one of the reasons that the raw data needs to be homogenized (although the deniers don't like that either, damned if you do, damned if you don't  ) 

Once again, I have trust in actual scientists research on Stevenson screens rather than some internet blogger desperately trying to create doubt and confusion.

Here is just one study on Stevenson Screens by the Royal Meteorological Society.

https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.2166

The_Barnacle wrote on Nov 10^th, 2019 at 10:39am:



oh dear. Poor barney has nothing. He doesn't want to know.

" The results show that the medium‐sized Stevenson screen tended to overheat daily maximum air temperatures (0.54 °C on yearly average) and also air temperatures recorded at 1300 UTC. The differences on daily minimum air temperatures were negligible (−0.11 °C on yearly average). "

https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/joc.4287#joc4287-bib-0006

"Quayle et al. (1991) found that in the USA daily maxima on average decreased by 0.4 degC while minima increased by about 0.3 degC, following the widespread changes that occurred largely in the 1980s – from taking temperature measurements using liquid‐in‐glass thermometers exposed in the Cotton Region Shelter (a louvered wooden screen similar to the UK Stevenson screen) to a thermistor‐based system exposed in a cylindrical plastic shelter. They concluded that without adjustments to the data, area averages of the mean diurnal temperature range could have biases as large as 0.7 degC. "

https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.2166

The_Barnacle wrote on Nov 10^th, 2019 at 10:39am:



So you have evidence they homogenise for Stevenson Screens or is that mere assumption? Although BoM does not keep the records.

Also homogenising records from differing loctions Darwin, Wyndham as an example; is what BoM does.

But you probably have a reason for that as well.

I had found that reference petal. Did you read it?

The reports say that that the changes increase temperature in the screens.

Meanwhile BoM has reduced the old data by homogenisation. Thus making it seem warmer than it was.

Edit: He still hasn't got back to us with reason for BoM making changes for statistical reasons. I guess they just plain "looked wrong".

Now for some FACTS.


"Global Warming is Unprecedented"
Is it really?

If global warming is indeed in some way unprecedented, then we would expect to find no match for the current global warming trend in the geological record. Let us consider just the most recent Holocene epoch - dominated by human history.

graph of climate data over the past 11000 years depicting two major Holocene Optimums
(warm periods), the Minoan Climate Optimum, the Roman Climate Optimum, the Medieval Warm Period,
and the less significant current warm period.


Average near-surface temperatures of the northern hemisphere during the past 11,000 years compiled by David Archibald after Dansgaard et al. (1969) & Schönwiese (1995).

Looking at just the historical picture, shown in the graph above, we can see that global warming has happened many times before in human history. We've had the Minoan Warm Period, the Roman Climate Optimum, and the Medieval Warm Period in addition to the current warm period (Dansguard et al., 1968; Schönwiese, 1995; Keigwin, 1996). Note the steepness of the rise in temperature at the beginning of the Minoan warm period. This rate of warming far exceeds that of the current warm period. Huang et al. (1997) determined that the depiction of the Medieval Warm Period in this graph may be somewhat conservative. According to their study of 6000 boreholes worldwide, the global mean temperatures of the Medieval Warm Period dwarf the changes of the Twentieth Century.

The evidence shows repeatedly that global warming is not unprecedented and according to Ruddiman (2001) as well as Singer & Avery (2006), global warming is a regular cyclic phenomenon on planet Earth. In fact, the normal global mean temperature for planet earth given the Phanerozoic history, is actually 19.5 degrees Celcius; a full three degrees higher than the present mean.

http://climate.geologist-1011.net/

The_Barnacle wrote on Nov 11^th, 2019 at 10:11am:



But is that normal variation or human induced?

What about all the extreme cold weather
events all over the world?

Bobby. wrote on Nov 11^th, 2019 at 10:17am:


As I've told you a million times before Bobby they are weather events, nothing to do with climate
You really do look stupid by bringing this up all the time 


Bobby. wrote on Nov 11^th, 2019 at 10:17am:


The standard argument by back flippers such as lee.
When I prove that the earth is warming he states "It's just natural variation"
When I prove that human emissions of CO₂ are accumulating in the atmosphere he states "but it's not warming"

For goodness sake. As more records are becoming digitised from old records, the data is duly adjusted to take account of more data points. Some data is adjusted due to more information, trying to get to a more accurate picture given the various frequency and reliability of older records.

If you were set the task to map the data since the 1860's you would do the same thing.

As more data becomes available, the figures become more representative and "rounding" and adjustments are made to account for the disparate sources of measurements.

Nothing untoward about this process at all.

They are trying to get the most accurate picture of what has been happening as is possible to do. 

If you still have doubts ... just take a look at the earlier fire seasons and longer and hotter heat events over the last few decades. It should be obvious that the planet is warming. 


I really don't get why you are still in denial about this.

What's the point of denying?

Sorry, I forgot ... it is pointless trying to discuss anything with you Lee.

Carry on.