But if we're pumping heat into the oceans at a phenomenal rate, why aren't the upper oceans warming?

Our effect on the earth is real: how we're geo-engineering the planet

Since the industrial revolution the added CO₂ now dissolved in the oceans has increased acidity by 25%. And it is changing the geological processes operating at the sea floor.
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And we are well on the way to doubling CO₂. In the past hundred years we have added almost 40%, and warming that can only plausibly be attributed to a greenhouse effect is not only heating the atmosphere, but is also pumping heat into the oceans and the crust at a phenomenal rate.

2011 Update Of The Comparison Of Upper Ocean Heat Content Changes With The GISS Model Predictions | Climate Science: Roger Pielke Sr.

It has now been at least since 2003 that there has not be significant heating of the upper ocean.
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OBSERVED BEST ESTIMATE OF ACCUMULATION Of JOULES [assuming a baseline of zero at the end of 2002].

2003 ~0 Joules
2004 ~0 Joules
2005 ~0 Joules
2006 ~0 Joules
2007 ~0 Joules
2008 ~0 Joules
2009  ~0 Joules
2010 ~0 Joules
2011 ~0 Joules through May 2011

Speaking [junk] science to climate [hoax] policy

We’re only a few decades away from a major tipping point, plus or minus only about a decade. The rate at which the ice sheets would melt is fairly uncertain, but not the result that says we are very close to a tipping point committing to such melt and breakdown.