Recent research shows that 90% of the increase in global ocean heat content during 2005-2015 was confined to the southern hemisphere. Using a collection of Argo-based data products and data assimilating model results, we show that this heating pattern of the ocean is most likely driven by anthropogenic climate change and an asymmetric climate variation between the two hemispheres. This asymmetric variation in the coupled ocean-atmosphere system is identified in 11 climate models with 6000 years of simulations of pre-industrial variability. The observed hemispheric asymmetry is more pronounced in the 0-700 m ocean layer than in the 700-2000 m layer. While both layers experience steady anthropogenic warming, 0-700 m layer also has prominent internal-decadal variability that we show is the primary contributor to the observed hemispheric asymmetry.  The rate of warming of our ocean observed from the Argo data is tracking the projected rate from climate model simulations. The changes in ocean heat content below 700 m have the higher signal to noise ratio for tracking anthropogenic warming, however, both layers indicate the robust detection of anthropogenic climate change. There appears to be no need for other hypotheses, such as aerosols, to explain the asymmetry in ocean warming over the 2005-2015 period.