The Stratosphere has cooled, but much of the trend results from the volcanic eruptions

The measurements of stratospheric temperature trends do indicate cooling which is consistent with the theory of AGW.

However, note the 'step-function' character around the eruptions of El Chichon (1982) and Pinatubo ( 1990 ). These eruptions injected particulate into the stratosphere, accounting for the temperature spikes. But when the dust settled, stratospheric temperatures fell to levels lower than before the eruption:




In fact, for the decade prior to El Chichon, there was a stratospheric warming trend. For the period after the resolution of El Chichon but before the eruption of Pinatubo, there was again a warming trend. And since the resolution of Pinatubo (sixteen years), the lower stratospheric trend has been flat. The middle and upper stratosphere have continued to cool ( again as predicted by AGW theory ), but clearly some of the cooling trend is accounted for by constituent changes forced by the volcanoes. And those changes remain poorly understood:

Global Warming is real but EXAGGERATED

For the twenty first century, the IPCC indicates the:

• Best estimate for a "low scenario" is 1.8 °C with a likely range of 1.1 to 2.9 °C
• Best estimate for a "high scenario" is 4.0 °C with a likely range of 2.4 to 6.4 °C

But what we observe from the satellite, surface, and sea surface data is as follows.

Below is the plot of temperature trends since the MSU era ( 1979 ).

For the MSU era, all trends are less than that of the Best estimate for a "low scenario".
Two ( the MSU middle troposphere ) are below the likely range.


Below is the post Pinatubo era, all trends are lower than those of the MSU era,
and most are less than the significance level.

Variance in Global Warming Input/Output Terms