I remember now
The the ice caps at latitudes that produce little angular momentum but when they melt the rise in sea level will be global and therefore the increased mass at the equator (and pro rata through the latitudes) means that the earth will slow down because the angular momentum hasn't changed but the radius of the mean mass has. That should produce a longer day. which maounts-up. Leap seconds here we come. Global warming? Know have thought through all the ramifications? Yea sure.

As for El Nino, if there is no leakage of momentum, any free mass that moves within the "mass of the whole earth" will force the other bits to accommodate. Jetstream is just such a free moving mass.

Just watch racing cyclists push their bike forward past the line, they do it by moving back on the bike. It reduces stage times by fractions but they all do it. Their momentum doesn't change but the front wheel gets there just a little bit sooner than if they didn't do it. 100 yard dash - they lean, same story.