The lower troposphere represents that layer of the atmosphere which is predicted to first experience the positive feedback of accelerated warming due to human greenhouse gases.
Recently, NOAA and NASA held a global warming presentation, which included various charts, and an unexpected admission that the atmosphere was not as warm as previous El Niño years.
An essential general review of the presentation can be found here.
The troposphere's lack of achieving the "warmest" year label was confirmed by the NOAA/NASA analysis of the relevant balloon and satellite datasets. And the adjacent chart is a combination from the NOAA/NASA presentation, with one chart being superimposed atop the other.
Other than a normal atmospheric response to the latest large El Niño temperature surge, the chart documents the continued lack of dangerous positive feedback warming.