The phrase
"peak warmth" refers to the highest level or maximum amount of heat or warmth that something can reach.
Full definition
Their reconstruction «shows a succession of warm and cold episodes
including peak warmth during Roman and Medieval times alternating with severe cool conditions centred in the fourth and fourteenth centuries.»
In January, Roy Spencer made the comment that, «We are now
approaching peak warmth in the tropics due to El Nino conditions.
Evidence for changes in precipitation is mixed: some studies show a dryer climate during
the peak warmth of the PETM, whereas others suggest that rainfall increased.
Of particular interest are the red and blue lines shown on the figure, which demark
the peak warmth experienced during the past century and the temperature anomaly expressing the current warmth, respectively.
The red line indicates the peak temperature anomaly of the past century, the blue line indicates the current temperature anomaly, the shaded red circles indicate periods in which temperatures were warmer than
the peak warmth of the past century, and the shaded blue circles indicate periods during the past century that were colder than present.
The changes in SST since the SAR are generally fairly small, though
the peak warmth in the early 1940s is more evident in the more recent analysis, supported by the NMAT analysis.