The realization of the temperature increase from the high level of solar activity was delayed / interrupted by a period of aerosol cooling, and there was also a significant, but not necessarily large, contribution from the increase in GHG forcing, and perhaps a contribution from internal climate variation as well. (realclimate.org)
These warming trends are consistent with the response to increasing greenhouse gases and sulphate aerosols and likely can not be explained by natural internal climate variations or the response to changes in natural external forcing (solar irradiance and volcanoes). (ipcc.ch)
It is obvious in retrospect that something else was happening — something now known as «internal climate variation». (watertechbyrie.com)