The IPCC's catastrophic AGW (CAGW) hypothesis is based on the prediction that human CO2 emissions would produce a "hotspot" in the atmosphere above the tropics. This hotspot was identified by the IPCC as the penultimate evidence that global warming was accelerating, causing a "tipping point" cascade of catastrophic events.
The projected hotspot over the tropics was expected to stretch from the 5km mark to as high as 15km, with the hottest portion being from 8-12km. The temperatures in this specific area were supposed to rise 1.2 to 1.5 times faster than surface temperatures, due to positive feedback loop produced by the CO2-induced warming.
Big problem though. As this chart of the lower troposphere (over the tropic latitudes) documents, NASA satellites are unable to locate this mysterious, runaway "hotspot" (AGW "signature" and/or "fingerprint") that the IPCC and global warming alarmists have long predicted. This despite NASA satellites having 100% coverage over the entire tropical troposphere, including the critical water vapor areas of the lower and mid-troposphere.
In fact, this specific area of the troposphere has only warmed a fraction of the IPCC's predictions, turning the "hotspot" into the embarrassing "AWOLspot." Additionally, this means that the feared AGW positive feedback loop went kaput, or it never really existed, except in the "consensus" hive mind of the alarmist-science collective.
Additional chart info: the red-dotted curve is a basic 36-month moving average; the green curve is 6th order fitted trend of monthly measurements; and the grey area represents the cumulative per cent growth of atmospheric CO2 levels. (Since satellite monitoring of atmospheric temperatures began, the cumulative growth of CO2 ppm levels has been over 18%.)
Per this satellite empirical evidence, the existing linear temperature trend of the low-troposphere tropic latitudes is ludicrously small, indicating that 2100AD temperatures may only increase by +0.6°C (necessary warning: trends are not predictions, don't go there). For the mid-troposphere tropics, the trend is even lower, +0.3°C. Compare those low trend rates with the modest warming trend of the entire atmosphere: +1.2°C by 2100AD.
And the comparison to the surface temps? NASA/GISS has a linear trend for the same time period projecting an outcome of +1.3°C by 2100AD.
Yep, you read that correctly. The tropical hotspot trends are lower than the global atmospheric trend and the global surface trend - a magnificent and spectacular fail of IPCC climate "science."
The simple, indisputable, scientific summary after 35 years of empirical evidence: The tropical, runaway hotspot did not happen in spite of massive amounts of CO2 emissions released into the atmosphere; ergo, the IPCC was wrong, again; the billion-dollar climate model predictions were wrong, again; alarmist, agenda-driven scientists' claims of climate doomsday were wrong, again; and, the fanatical anti-CO2 green lobby was wrong, as always.
Note: Links to datasets used in Excel to create chart: UAH satellite & NOAA CO2. Don't know how to chart in Excel? It's easy. Go here to learn how.