Why it is in the news
A reconstruction reaching back roughly nine centuries reports that El Niño events have intensified relative to the pre-industrial period, with the sharpest increase in recent decades.
The exam angle
The examinable content is the ENSO mechanism and its threshold, not the study. Expect the +0.5 °C declaration threshold and the caveat that El Niño is statistically, not deterministically, linked to a weak monsoon.