One-third of Man’s entire influence on climate since the Industrial Revolution has occurred since January 1997. Yet for 224 months since then there has been no global warming at all (Fig. 1). With this month’s RSS (Remote Sensing Systems) temperature record, the Pause sets a new record at 18 years 8 months.
As ever, a warning about the current el Ni√±o. It is becoming ever more likely that the temperature increase that usually accompanies an el Ni√±o will begin to shorten the Pause somewhat, just in time for the Paris climate summit, though a subsequent La Ni√±a would be likely to bring about a resumption and perhaps even a lengthening of the Pause.
The spike in global temperatures caused by the thermohaline circulation carrying the warmer waters from the tropical Pacific all around the world usually occurs in the northern-hemisphere winter during an el Ni√±o year.
However, the year or two after an el Ni√±o usually ‚Äì but not always ‚Äì brings an offsetting la Ni√±a, cooling first the ocean surface and then the air temperature and restoring global temperature to normal.