How can a person have confidence in the global warming caused by CO2 emissions theory when the temperature charts seem to be so full of discrepancies, bad data, data cleansing, poor placement of measuring equipment and indications of political manipulation?
One of my favourite blogs is WattsUpWithThat because I am amazed at the number of problems there seem to be with what I would have expected was very straight forward basic data.
Placement of weather stations
Weather stations are often placed at airports. This makes sense on an efficiency basis, because aircraft pilots need weather information for take-off and landing. However, they are not great places for getting temperature data. Planes create heat from their engines. Runways are upgraded from grass to bitumen. Carparks are built and expanded. Buildings are built up and airconditioners and other heat creating plant built in.
Many other weather stations are in urban centres. This also makes sense as weather bureaus want to give weather information to the largest section of the population. However, urban centres have also become more built up – more roads, more buildings, more heat producing car engines, air conditioners, etc. A weather station placed close to a building, and/ or with new buildings and new airconitioning condensing units blowing towards them would provide higher temperature readings over time as more of the warming infrastructure is placed around it.
The problem here is the local environment of many weather stations have become warmer due to urbanisation, and don’t necessarily reflect climate changes.
Moving weather stations to new locations
From time to time the powers that be deem the existing location of a weather station to be unsuitable and relocate it elsewhere. Sometimes the new location is more suitable, sometimes less suitable. The problem here is that the readings before and after the move are no longer comparable. A move closer or further from heat sources, up or down hill, into or out of breeze ways can change the temperature readings significantly from a move of even a short distance.
Change in surrounding land use
A change in the use of the land in the district where the weather station is located will cause the local temperature to change over time. A change from forest to agriculture, or from agriculture to suburbia, or even suburbia to high density buiildings will change the amount of heat absorbed and reflected in the district.
Old equipment or faulty equipment
I have read a number of discussions about the accuracy and reliability of different types of equipment used for measuring temperature. While I admit I only understand part of it, I do understand enough that some equipment gives a warming feedback into itself by the way it has been designed. There is also the issue of calibration which I will include under human error.
Not all weather stations are electronically interfaced with the recording and reporting authority. Many weather stations still require physical readings by a human being. Others give electronic readouts, but the data needs to be transcribed by a human being into the database or a communications system.
There are gaps in some data sets because the person who is responsible for taking the readings didn’t do it that hour/ that day/ that week.
Temperature measuring equipment needs to calibrated by the manufacturer and/ or installer and/ or maintenance staff.
There are a few ways human error can come into the data.
Apparently one doesn’t just collect all of the readings for a certain time and take the average to work out the global temperature. There is an algorithm which is used to take into account a number of factors, one of which I hope is the area covered. However, this algorithm and the data sets put into the algorithm apparently change from time to time. Possibly this is due to better understanding of how the data should be amalgamated, but it is also open to the suspicion of political interference.
Change in number of weather stations
The number and location of weather stations around the world changes from time to time. There is a very interesting post about the change in the number of weather stations around the world from the 1950’s through to current times at M4GW‘s website. The figures and area quoted aren’t quite correct, but the official GISS website does report a gradual increase in the number of stations used from a few hundred in 1860 to about 3000 in 1950, then a quick increase to about 6000 in about 1970, and then a rapid drop in about 1990 from about 5000 to about 2500 stations. How does one maintain comparability of data with this degree of change in the source data set?
This is the graph from GISS:
Another interesting point is that there is much greater coverage of the northern hemisphere than of the southern hemisphere. Don’t two halves make a whole?
Different data sets used for different charts
There are different collections of temperature data, and each one gives a different picture. The best trick I have heard of yet is the allegation that IPCC stitched together the data up to about 1980 from one data set and the data from another source from 1980. This resulted in the famous “hockey stick” graph which purported to show the planet has been warming at an alarming rate. The recent trend in the graph was then extrapolated to show that in about 100 years time the global temperature would go through the roof. Such stunts do not do anything for public confidence in the global warming theory, particularly when it came from the IPCC.
Ignoring or removing readings
A couple of places in the US have recorded the lowest temperature ever. Watts Up With That website is concerned that these lowest ever readings have been struck from the official record –
The above problems are with regard to weather stations which measure surface temperature.
Satellite data is now available. Satellites measure the temperature in the lower atmosphere, not surface temperatures, so one would expect the raw data to be different, but the trends should be the same. However, can one have confidence in the published data from that source? How much of the planet is covered by these temperature readings? How often are temperatures measured at each point? What data “adjustment” is applied to these readings?
Has anyone got the answers to these questions?