Northern and Southern Hemisphere Warming – Rising Because of That?

By Andy May

Often the media press and scientists consensus report global average surface temperatures without mentioning that both warming rates and average temperatures vary greatly around the Earth in a year. For example, Earth’s global average surface temperature varies by about 7°F per year. The ratio also varies by hemisphere. Phil Jones and associates^[1] shows that the average global monthly temperature, from 1961-1990, was about 54°F in January and 61°F in July. In the Northern Hemisphere, temperatures vary from 46°F in January to 70°F in July, and the average temperature in the Southern Hemisphere, respectively, is 61°F and 51°F.

As shown in Figure 1, the Hadley Climate Research Unit HadCRUT5 Temperature data sets show that the Northern Hemisphere was 0.74°C (1.3°F) warmer than the Southern Hemisphere from 1979 to 2021. UAH The lower troposphere satellite temperature record is in a similar direction but the difference between the hemispheres is much less, as shown in Figure 2. Both figures have an identical vertical scale of 1.4°. C. The difference in global warming for the UAH satellite, from 1979 to 2021, between the hemispheres is about 0.2°C (0.4°F), less than a factor of 3.

The Southern Hemisphere warming rates for UAH and HadCRUT5 are roughly the same, both around 0.2 F per decade. But the rate in the Northern Hemisphere is very varies, the HadCRUT5 rate is about 0.5 degrees Fahrenheit per decade and the UAH rate is 0.29 degrees Fahrenheit per decade. The rate of HadCRUT5 in the Northern Hemisphere is 72% higher than that of satellite UAH. In the Southern Hemisphere, the UAH warming rate is slightly larger than the HadCRUT5 rate, but the difference is very small, only 5%, and probably insignificant. But 72% is certainly significant.

The difference in hemispheric warming rates is characteristic of orbital and solar forces due to the tilt of the Earth’s axis relative to the orbital plane combined with the Earth’s rotation. It is not characteristic of coercion due to well-mixed greenhouse gases, like CO₂. The rate of HadCRUT5 warming in the Northern Hemisphere is questionable.

About 68% of Earth’s land area is in the Northern Hemisphere, and the HadCRUT5 surface temperature record is a combination of two very different datasets. The HadSST4 The Sea Surface Temperature Dataset measures temperatures at ocean depths of about one foot and CRUTEM5 The land surface dataset measures air temperature at an altitude of about 6 feet. The UAH satellite dataset is a lower troposphere dataset and measures air temperature at about 10,000 feet, the measurements are all made using the same satellite data, as explained in the section below. before mine parcel.

Maybe the urban heat island effect,^[2] combined with Hadley Center UK “uniformity“The algorithm contaminated the mainland-only CRUTEM5 recording and distort it.^[3] Since land surface temperatures often vary greatly over short distances, it is necessary to “homogenize” or flatten them to obtain mapable values. One of the major differences is between cities and rural weather stations, as cities are warmer than the surrounding countryside due to sidewalks, cars, air conditioners, etc. The difference is the island effect. urban heat, and as Nicola Scafetta explains^[3] Homogeneity of surface temperatures has the effect of spreading warming in cities over large areas. He calls this “urban fusion”.

If we consider the whole HadCRUT5 hemisphere profile, the difference in scale shown in Figure 1 is even more suspicious, as shown in Figure 3. The very large difference between hemispheres was not seen in previous years of the HadCRUT5 record.

Conclude

The UAH and HadCRUT5 records both show that the Northern Hemisphere is warming faster than the Southern Hemisphere, but the amount of extra warmth in the HadCRUT5 record is unusual. While the proportions of satellites and the surface of the Southern Hemisphere are similar, the proportions of satellites in the Northern Hemisphere are very different.

The troposphere is lower than the global UAH and HadSSTThe 4 warming rates are all 0.14°C/decade from 1979 to 2020, the same to two decimal places, as shown in my previous section parcel. Oceans cover 70% of the Earth’s surface and the HadSST4 dataset is used in conjunction with CRUTEM5 The land surface temperature record to produce the curves is shown in Figure 1. Therefore, the large difference in warming rates in the Northern Hemisphere between Figure 1 and Figure 2 is difficult to interpret. Honestly, it shows there is a problem with CRUTEM5. Figure 3 shows that the problem is getting worse in recent years, not better. This topic is discussed in more detail in my latest book: The Great Climate Change Debate: Karoly v Happer.

Folder can be downloaded this.

This post was originally published at HAVE₂ League.

1. (Jones, New, Parker, Martin, & Rigor, 1999) ↑

2. The Urban heat island The effect is the result of humans expanding the land and replacing trees and plants that have a natural cooling effect. Humans also have air conditioners, factories and vehicles. Cities can be up to 7 degrees warmer than the surrounding countryside. ↑

3. (Scafetta, 2021) explains how urban heat islands break global surface temperature records. ↑