By P Gosselin on 1. January 2022
There’s been no warming in Tokyo in decades!
By Kirye
and Pierre
The December-2021 mean temperature data from the Japan Meteorological Agency (JMA) for Tokyo and its Hachijō-jima island in the Pacific are in and so first we look the December trends side-by side:
Data source: JMA
Since 1985, the mean monthly temperature for December in Tokyo has been flat since 1975.
The island of Hachijō-jima, located some 287 kilometers south of Tokyo, thus far away from all the urban sprawl and heat island affects, has also seen a flat mean temperature trend – since 1923!
Nothing unusual is happening at these two very different stations in December.
Annual mean temperatures show no warming!
But that’s only a trend for a month. Now that December data are available, it is possible to update the annual temperature trend for these two stations.
First we plot the JMA mean annual temperature for Tokyo going back to 1994:
Data source: JMA.
Here we see that the megalopolis has been cooling moderately, thus defying the predictions of warming. Despite the sprawling megalopolis of steel, asphalt and concrete, Tokyo has been cooling off.
Obviously there’s something other than trace gas CO2 driving the trends there.
Hachijō-jima
Moving offshore to the Tokyo island of Hachijō-jima, away from all the urban heat island affects, we look at the newest mean annual temperature going back to 1950.
Has it been warming or cooling?
Data source: JMA.
If we look closely at the chart, we see there’s something natural and cyclic behind the temperature at the island in the Philippine Sea, but overall no warming in over 70 years!
Warming, change, observed and modeled trends, records with impulse impurities, and propagation of errors including attribution.
Seems to me that deserts would be the ideal place to look for warming. Islands would be the worst place to look for warming.
You can look for warming anywhere. If you focus on deserts you’ll determine the warming rate for deserts. If you focus on islands you’ll determine the warming for islands. If you focus on land you’ll determine the warming for land. If you focus on oceans you’ll determine the warming for oceans. So on and so on. If you consider all areas you’ll determine the warming globally. It just depends on which area you want to determine the warming. Different areas will have different warming rates. You’ll even find that some areas are actually cooling.
You just described why it is important to know the absolute temperature of an average AND THE VARIANCE that is expected with a specific mean. The “uncertainty” (it is not) stated with a Global Average Temperature when it shows precision out to 1/100ths to 1/1000th is not a statement of the standard deviation of the data.
People deserve to know what the true standard deviation of the entire absolute temperatures in a data base actually is. They would be surprised to see the range from the winter in Antarctica to summer in the tropics, all on the same day of the year.
“People deserve to know what the true standard deviation of the entire absolute temperatures in a data base actually is.”
For every time period evaluated, there is the sum of the variances between the expected values of of each station reading, and its calculated value, from spatially weighted averaging. There is also the sum of the variances found from the square of the standard deviations of the measurement error of every station. These can be simply added, and then using the normal weighted averaging statistical laws, the standard deviation of each “entire” temp/date point can be found.
The Berkeley Earth temp data is the best example I know of where that parameter is provided.