By Dr. John Happs
Channel 7 and Channel 9 news were quick to announce that Perth experienced its highest temperature on record on Saturday, 16th November 2019.
We were told that the temperature reached 40.8oC and a record temperature was claimed. Of course we were not told exactly where that particular temperature was taken and why that “record temperature” was not recorded in neighbouring suburbs.
Interestingly, that“record temperature” of 40.8oC was measured at Perth Airport at 2.00 pm. Also at 2.00 pm, the temperature in Perth City was 38.6oC. Still hot, but 2.2oC lower than Perth Airport.
So what about the temperature in suburbs further west of the airport? Hillarys for instance recorded 24.30oC at 2.00pm on the same day – a whopping 16.5oC lower than the airport “record temperature.”
Differences in temperatures between suburbs is common across Perth or any other city. For instance on the 9th November, 2019, the temperature at Perth Airport at 3.00 pm was 39.3oC whilst the temperature at Hillarys was 26.6oC at the same time. A difference of 12.7oC.
On the 14th November 2019, the temperature at Perth Airport at 1.00 pm was 38.5oC whilst the temperature at Hillarys was 24.8oC at the same time. A difference of 13.7oC.
So why the discrepancy and why should we be skeptical of media claims of a record temperature for Perth on the 16th November 2019 or any other date?
To ensure standard measurements from meteorological instruments, the World Meteorological Organization (WMO) has specified the construction and placement of the Stevenson Screen, invented by the British engineer and meteorologist Sir Thomas Stevenson (1818-1887), father of author Robert Louis Stevenson (1850-1894) of Treasure Island fame.
The Stevenson Screen offers instruments protection from leaves, animals, rain, snow and wind and is painted white to reflect direct solar radiation. It is a double-louvered box that allows the free passage of air and it holds instruments such as maximum/minimum thermometers, hygrometers for measuring relative humidity and a barometer for measuring atmospheric pressure.
Stevenson Screens should be kept 1.25 metres off the ground and be on a level piece of ground that is covered with short grass. It should be erected well away from any trees or buildings.
Temperature measurements from many land-based thermometers provide readings that are highly questionable. When temperatures are taken in urbanised area, they are likely to produce a significantly inflated reading due to artificial heating from surrounding buildings, paving and roadways.
At airports, where information about temperature, wind strength and direction are needed for operational aircraft, WMO locations and conditions for measurements might be difficult or impossible to meet. Consequently, temperatures measured at airports are almost certainly going to be higher than surrounding suburbs due to the Urban Heat Island Effect.
Record surface temperatures, often paraded by climate alarmists, are likely to be exaggerated by urbanization. Heat from the sun is retained by buildings and roadways and re-radiated. This is why cities and airports are referred to as Urban Heat Islands and this effect can be shown in profile:
Cities and airports have large areas of concrete and asphalt in roads and runways. Additionally, buildings can funnel and concentrate heated air such that any weather station placed in this environment will inevitably return an exaggerated high temperature reading.
Urban Heat Islands are better monitored from space as seen on the following NASA map plotted across Paris in June 2019:
Note the temperature at the Charles de Gaulle airport compared with the surrounding area.
In the same month (June, 2019) a NASA satellite temperature survey across Rome showed similar heat island results:
Note the temperature at Rome’s Leonardo da Vinci airport compared with the surrounding area and a similar problem is seen at Wichita airport in Kansas where a “record” high temperature was claimed on the 4th May, 2014.
The red circle shows the position of the weather station and we shouldn’t be at all surprised that an inflated temperature measurement was attained here when the station is close to jet aircraft burning fuel and releasing hot exhaust gases.
Other examples where daily maximum temperatures at airports have been exaggerated can be located at:
Minimum temperatures are also clearly influenced by the positioning of weather stations and there could be significant differences (by several degrees) across any suburb. Senior meteorologist Blair Trewin from the Australian Bureau of Meteorology (BOM) has acknowledged:
“The minimum temperature could have quite big variations within a suburb – by up to several degrees.”
Perth geoscientist Warwick Hughes looked closely at the temperature data assembled by scientists from the Climate Research Unit (CRU) at the University of East Anglia in the UK, later to be at the centre of the Climategate scandal. The CRU was responsible for collating temperature data from around the world and those data were used by the now discredited Intergovernmental Panel on Climate Change (IPCC).
Hughes examined the Southern Hemisphere temperature trends that the CRU’s Dr. Phil Jones had published. Hughes showed that virtually all the warming claimed by Jones resulted from the Urban Heat Island Effect.
When Hughes expanded his analysis of the CRU data collected from South Africa and Siberia he concluded that:
“Cities are the source of the apparent warming, which is not apparent at nearby small towns or rural stations.”
When Hughes requested more data and information from Jones in 2005, Jones told Hughes that he would not send more data, saying:
“We have 25 or so years invested in the work. Why should I make the data available to you, when your aim is to try and find something wrong with it?”
Many people innocently believe that scientists will always deliberately seek constructive criticism from their peers so that science can advance from such criticism. Apparently climate alarmists don’t subscribe to this view.
There are numerous peer-reviewed, published papers that show how terrestrial temperatures are affected by weather station shifts, changes in instrumentation, observation patterns and recording bias. Perhaps of more importance, there are problems with bad positioning and changes in the land surrounding the weather station.
Examples of land changes close to weather stations have been provided by Fall et al. (2010)
This station is at Tucson University, Arizona and is one of many investigated by Fall et al.
“The comparison of time series of annual temperature records from good and poor exposure sites shows that differences do exist between temperatures and trends calculated from USHCNv2 stations with different exposure characteristics.”
Anthony Watts and his team of 650 examined more than 800 weather stations across the US and concluded:
“We found stations located next to the exhaust fans of air conditioning units, surrounded by asphalt parking lots and roads, on blistering-hot rooftops, and near sidewalks and buildings that absorb and radiate heat. We found 68 stations located at wastewater treatment plants, where the process of waste digestion causes temperatures to be higher than in surrounding areas. In fact, we found that 89 percent of the stations – nearly 9 of every 10 – fail to meet the National Weather Service’s own siting requirements that stations must be 30 meters (about 100 feet) or more away from an artificial heating or radiating/ reflecting heat source. In other words, 9 of every 10 stations are likely reporting higher or rising temperatures because they are badly sited.”
So much for meeting the rigorous standards set out by the WMO or the National Oceanic and Atmospheric Administration (NOAA).
Watts and Pielke examined temperature monitoring stations in the USA and showed that only 11% actually met WMO or NOAA standards.
Dr. John Christy points out that the surface temperature readings upon which global warming hysteria is built have been distorted by urbanization and that many cities, where “official temperatures” are recorded, are 7 or 8 degrees warmer than the surrounding countryside.
Dr. John Christy and Dr. Roy Spencer analyzed temperature readings from NOAA and NASA satellites, finding significantly lower temperatures being returned from satellites compared to those recorded at surface stations.
There is now widespread agreement that temperature data from cities and airports are “contaminated” and exaggerated by Urban Heat Island bias and this must be removed if we are to have more reliable and believable surface temperature records.
Many peer-reviewed, published studies have shown how the Urban Heat Island bias inflates temperatures in many parts of the world leading Block et al. (2004) to conclude:
“The local amount of warming is considerably affected by the surrounding orography.Therefore regional climate models should take anthropogenic heat into account to improve their performance.”
From China, Zhou et al. (2004) report:
“Rapid urbanization in south-eastern China in the past 25 years is responsible for an estimated warming rate much larger than previous estimates for other periods and locations.”
Hinkel et al. (2003) found similar problems:
“Here, we demonstrate the existence of a strong urban heat island (UHI) during winter. Data loggers (54) were installed in the ∼150 km2 study area to monitor hourly air and soil temperature, and daily spatial averages were calculated using the six or seven warmest and coldest sites. During winter (December 2001-March 2002), the urban area averaged 2.2 °C warmer than the hinterland. The strength of the UHI increased as the wind velocity decreased, reaching an average value of 3.2 °C under calm conditions.”
A 2010 study by NASA concluded:
“Summer land surface temperature of cities in the Northeast were an average of 7°C to 9°C (13°F to 16 °F) warmer than surrounding rural areas over a three year period, the new research shows. The complex phenomenon that drives up temperatures is called the urban heat island effect.”
Satellite telemetry is providing better understanding of the Urban Heat Island effect and has been used to compare various urban settings. Ping Zhang, lead author of the NASA research said:
“This, at least to our knowledge, is the first time that anybody has systematically compared the heat islands of a large number of cities at continental and global scales,”
Another clear example (from many) of Urban Heat Island temperature distortion was seen when the UK media and Met Office were quick to claim that a temperature record had been set on the 1st July, 2015 at Heathrow Airport where the thermometer registered 36.8oC.
Of course the temperature measured in other parts of the UK were conveniently ignored and the public was led to believe this was evidence of (imaginary) global warming and that large areas of runways, buildings and jet engine exhaust had nothing to do with that high temperature of 36.8oC. Data from other locations, on the same date and time, proved otherwise:
When temperature data from Heathrow were compared with data from other sites around the UK on the same day, the Urban Heat Island impact soon became apparent but the public remained blissfully unaware of this.
Returning to the claim that Perth experienced its highest temperature on record on Saturday, 16th November 2019, we need to consider the location of Perth airport. In fact it is located well inland:
Like most airports, it has large areas covered by concrete and there are many buildings and car parks in the vicinity.
It is interesting to note that climate alarmists usually refer to terrestrial (ground-based) temperatures when claiming that the planet is warming. They rarely (if ever) mention the lower troposphere temperatures as measured by a series of satellites. Satellites provide data accessible to all and those data are not subjected to “adjustment.”
IPCC contributing scientist Dr Robert Davis agreed, saying:
“Global temperatures have not been changing as state of the art climate models predicted they would. Not a single mention of satellite temperature observations appears in the (IPCC) Summary for Policymakers.”
Only satellite data provide reliable records of lower troposphere temperatures since their microwave radiometers, with calibrated platinum resistance devices, have a proven long-term stability. Coverage of the whole planet is possible and temperature measurement is extremely accurate. NASA has made clear:
“Satellite analysis of the upper atmosphere is more accurate, and should be adopted as the standard way to monitor global temperature change.”
Try telling that to those climate alarmists who refer only to terrestrial temperature data!
UAH lower troposphere satellite data provide the most comprehensive and accurate global temperature measurements and there is no indication of a warming trend. Even the alarmist Intergovernmental Panel on Climate Change (IPCC) now acknowledges there has been no global warming for at least 15 years, despite rising levels of atmospheric carbon dioxide.
The IPCC reported that the gentle end of 20th century warming has stopped. The IPCC’s Chapter 9 of the WG1 Report discusses the hiatus under Box 9.2: Climate Models and the Hiatus in Global-Mean Surface Warming of the Past 15 Years.
Under Box 9.2 we read:
“Nevertheless, the occurrence of the hiatus in GMST trend during the past 15 years raises the two related questions of what has caused it and whether climate models are able to reproduce it.”
Dr. Howard Hayden observes:
“If the science were as certain as climate activists pretend, then there would be precisely one climate model, and it would be in agreement with measured data. As it happens, climate modelers have constructed literally dozens of climate models. What they all have in common is a failure to represent reality, and a failure to agree with the other models.”
Dr. Phil Jones, former director of the Climatic Research Unit (CRU) at Britain’s University of East Anglia conceded that there has been no “statistically significant” rise in global temperature since 1995.
Dr. Khabibullo Abdusamatov, head of the space research facility at the Pulkovo observatory in St. Petersburg warns of low solar activity and global cooling which could continue for 2 or more decades. He states:
“By the mid-21st century the planet will face another Little Ice Age, similar to the Maunder Minimum, because the amount of solar radiation hitting the Earth has been constantly decreasing since the 1990s and will reach its minimum approximately in 2041.”
The UK’s Royal Society has admitted in a statement on the science of climate change that the previous spell of warming ended in 2000.
The Journal Science has said the pause in global temperature is real, as do many refereed scientific papers in numerous journals.
Climate scientist Dr. Judith Curry said it is now clear that the IPCC’s computer modeling, which predicted continual warming, is deeply flawed. She suggests that all climate scientists should:
“Use this as an opportunity to communicate honestly with the public about what we know and what we don’t know about climate change. Take a lesson from other scientists who acknowledge the “pause”.
Temperature data from Greenland, Antarctica, the Himalayas, New Zealand, Portugal, China, Canada and a host of other countries show there has not been any warming for many years.
We can expect more record temperatures to be declared for Perth in the future. After all, it is a growing city and the airport will inevitably see more runways and buildings and exaggerated temperature readings will continue to be paraded by the media.
There will be no mention of temperature trends at locations such as Cape Leeuwin in the south of Western Australia, away from any heat islands and with 120 years of temperature data. Winemaker Erl Happ has been a long time weather-watcher in this area and notes:
“The warmest decade in January occurred in 1979-1988. The failure to warm indicates that the much celebrated hypothetical link between carbon dioxide and atmospheric temperature is absent.”
Climate alarmists, including a number of scientists, will routinely cite terrestrial thermometer readings whilst ignoring data from satellites and radio-sonde balloons. They will do this because uncontaminated satellite and balloon data show no significant warming and this does nothing to promote the human-caused climate disasters they so desperately need to promote. After all, nothing attracts research funding like a looming disaster that scientists say is real and only they can provide a solution.
Dr. Christian Schuchter, emeritus professor at the University of Bern in Switzerland explains:
“As a number of other prominent climate scientists I know will attest, there’s one broadly recognized universal tip for those seeking government funding. All proposals with any real prospects for success should somehow link climate change with human activities rather than to natural causes. Even better, those human influences should intone dangerous consequences.”
Nobel Laureate Dr. Ivar Giaver has referred to the notion of catastrophic anthropogenic global warming as an ideology and he could well have been referring to the selection of exaggerated terrestrial temperature data as an example when he described:
“A pseudoscience that begins with an emotionally-appealing hypothesis and then looks for items which appear to support it while ignoring ample contrary evidence.”
The next time anyone tells you about a new temperature record, be sure to ask the following questions:
EXACTLY WHERE was the temperature taken?
EXACTLY HOW was the temperature recorded?
Has the measuring site CHANGED over the years?
Dr. John Happs M.Sc.1st Class; D.Phil. John has an academic background in the geosciences with special interests in climate, and paleoclimate. He has been a science educator at several universities in Australia and overseas and was President of the Western Australian Skeptics for 25 years.