Distinguished New Zealand meteorologist Dr John Maunder reports on minimal changes in temperature in the troposphere: "The chart created by the University if Alabama, Huntsville, USA, shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16."