The Earth's Atmosphere is Warming Very Slowly

The graph below shows the temperature changes of the lower troposphere from the surface up to about 8 km as determined from the University of Alabama in Huntsville (UAH) analyses of satellite data. Surface temperature data is contaminated by the effects of urban development. The Sun's activity, which was increasing through most of the 20th century, has recently become quiet. The magnetic flux from the Sun reached a peak in 1991. The high magnetic flux reduces cloud cover and causes warming. Since then the Sun has become quiet, however it continues to cause warming for a few decades after its peak intensity due to the huge heat capacity of the oceans. The green line shows the CO2 concentration in the atmosphere, as measured at Mauna Loa, Hawaii. The ripple effect in the CO2 curve is due to the seasonal changes in biomass. There is a far greater land area in the northern hemisphere than the south that is affected by seasons. During the Northern hemisphere summer there is a large uptake of CO2 from plants growing causing a drop in the atmospheric CO2 concentration. The El Chichon and Pinatubo volcanic eruptions in 1984 and 1994 caused short-term cooling. The temperature spikes in 1998, 2010 and 2016 were cause by strong El Ninos. Natural climate change is stronger than the effect from carbon dioxide.

Global Lower Troposphere Temperatures and CO2

A best fit trend from 1979 to January 2022 indicates a warming of 0.58 °C over 43 years.

A surface temperature index over land is produced by the Climate Research Unit (CRU), University of East Anglia, U.K. The graph below shows the average annual temperatures from 1940 over land from 40 °N to 60 °N and all longitudes represented by the middle, green line. The top line is the July daily maximum average temperatures and the bottom line is the January daily minumum average temperature for the same area. When considering the range of temperatures commonly experienced, the increase in annual average temperatures appears very small. The recent increase in temperatures is very slow. Most of the temperature increase is in the minimum temperatures which increased 3.1 times faster than the maximum temperatures. Many studies show that about half of the surface station temperature rise over land is caused by urban warming. See the Urban Heat Island Effect (UHIE) section in the Climate Science 'Library'. Urban waming has only a little effect on satellite data.

Land Temperature 40-60N min, max, ave.

The graph below shows the HadCRUT5 global (land & sea surface) temperatures corrected for the UHIE and the multi-model mean simulations from 1980 to 2021with the trend lines. The graph shows the simulated trend is 149% of the measured trend. Te UHIE correction of 0.040 °C/decade. HadCRUT5 is the Hadley Centre (sea) and CRU (land) combined temperature dataset version 5.

Global surface temperature from 1980 HadCRUT5

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