evidence: Using the data that were available at the time (through 2012), the last climate report from the Intergovernmental Panel on Climate Change concluded that there had been no statistically significant increase in global surface temperature from 1998-2012. [...] The most likely explanation for the lack of significant warming at the Earth’s surface in the past decade or so is that natural climate cycles—a series of La Niña events and a negative phase of the lesser-known Pacific Decadal Oscillation—caused shifts in ocean circulation patterns that moved some excess heat into the deep ocean. Even so, recent years have been some of the warmest on record, and scientists expect temperatures will swing back up soon. [...] Just because the global surface temperature has not risen significantly in the past decade doesn't mean the Earth's heat energy imbalance has vanished, though. Excess heat energy trapped by greenhouses gases can have more than one fate in the Earth system; among other things, it can cause water to evaporate, it can melt ice, and it can be mixed into the deep ocean by overturning currents.