claim: So it’s been a surprise to climate scientists that 2017 has been so remarkably warm — because the last El Nino ended a year ago.
evidence: La Nina (  / lɑːˈniːnjə / , Spanish pronunciation : [ la ˈniɲa ] ) is a coupled ocean-atmosphere phenomenon that is the colder counterpart of El Nino, as part of the broader El Nino–Southern Oscillation climate pattern.