Model Generated vs Observed Temperature Data
Given that the discussion has repeatedly referred to the difference between computer model generated temperature profiles and the observed global temperatures, I am compelled to include a brief discussion to address those differences. The above presentation (or some variation) is routinely used to compare the model generated temperatures with weather balloon and satellite measurements. I do not have the data tables to plot the data myself so I am relying on the work of others. These charts come from a temperature comparison discussion put forward by Judith Curry. That discussion is worth reading and is much more detailed than what I will present here.
The temperatures plotted here represent the earth’s mid-Troposphere (surface to 50,000 feet). Do not confuse these temperatures with surface temperatures. The Troposhere temperature is chosen because this is the atmospheric layer that should be most affected by rising CO2 levels (according to the computer models). That just isn’t happening. The temperatures have been relatively flat through the first 16 years of this century based on both satellite and weather balloon data.
The models predicted that the mid-Troposheric temperature anomalies would be 0.85 °C above the base (0.0 °C). The actual temperature anomaly is only 0.3 °C. The models are overstating the temperature by 183.3%. Sadly, these models are still being used to justify climate change policy despite their obvious inaccuracies.
The surface temperature estimates in the models are also overestimated. Actual measured surface temperature trends are well below the model averages (despite the homogenization processes’ upward adjustments). The trends are generally closer to the lower limit (2.5%) than the average for most of the dataset. All of the recent trends are below 0.2 °C/decade (2 °C/century) and declining. Those are not alarming numbers.