From Simon Donner, about as clear an explanation I've heard re the "pause" in AGW (which isn't really a "pause" in any case):
Over the past 10-15 years, the global mean surface air temperature did not increase at the rate of the previous decades. The cause of the slowdown is primarily natural variability, variability that is driven by long-term oscillations in the oceans. The planet is still adding heat - we can see in this planetary energy balance data. The difference is for the past few years, more of that heat is gathering in the deep ocean.
In a few years, the yin of deep ocean heating will give way to the yang of surface temperature warming. Among other things, we'll see full El Nino events develop again - there has not been one since the climate shifted in 1998, something my lab is studying - and with that, new global surface temperature records.
So there you have it.