A previous publication by the author predicted that global temperature patterns will switch from the sinusoidal (amplitude-modulation) state into which it has been since 1944 into a node-antinode (amplitude-modulation) state somewhere over the 1997-2012 period. Here we present record-backed evidence which shows that the state change just mentioned is apparently in the process of starting up. By its very nature, this imminent (node-antinode) state is expected to make global temperature vary significantly above and below a common mean which itself may be approximately constant or may at certain times undergo relatively slow drifts. Furthermore we present a historical example in which records of temperature-sensitive indicators show that at least some regional temperature patterns have at least once switched from the sinusoidal (amplitude-modulation) state to the node-antinode state under global climate conditions that were fairly similar to those of the present. Finally we propose possible physical causes of the latter historical switch from sinusoidal state to node-antinode state.