In Hansen’s world, 2010 was La Nina and 2011 is El Nino.
Even for a near record-breaking year like 2010 the broader context is more important than a single year. “Certainly, it is interesting that 2010 was so warm despite the presence of a La Niña and a remarkably inactive sun, two factors that have a cooling influence on the planet, but far more important than any particular year’s ranking are the decadal trends,” Hansen said.
(2011) Based on subsurface ocean temperatures, the way these have progressed the past several months, and comparisons with development of prior El Niños, we believe that the system is moving toward a strong El Niño starting this summer. It’s not a sure bet, but it is probable.
So now we know – cold La Nina brings positive anomalies and warm El Nino brings negative anomalies.