If this holds up, would it be reasonable to assume the NH is warming up and the SH cooling off? This is not necessarily the case, the global heat engine is so complex it might be a symptom of some deeper, counter-intuitive, underlying process. But with the bulk of the water in the SH, and hence more thermal inertia, maybe it's evidence of some net heat transfer across the equator. I may be wrong, but I always understood each hemisphere's heat engine was roughly independent of the other, and energy transfer was between equator and poles, away from the equator. It definitely appears something is going on, but it's not clear just what. Let's hope some new equilibrium is reached without any abrupt changes of state. I still will be willing to bet that no "runaway" phenomenon is likely.