The strongest indicator that we are on a cusp of rapid warming is the ARGO buoy global ocean heat content series published by the National Center for Environmental Information (formerly NODC).
https://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/The earth's oceans experience about 93% of the total expression of global warming since the cooler body of water has the greatest rate of heat energy transfer. Having an accurate assessment of this heat accumulation shows how the rate of warming has been growing.
Since the earth's hemispheres are so different with the vast majority of the ocean surface area located in the southern hemisphere, the rate of globally averaged ocean heat energy gains fluctuates with the seasons, dropping in the southern hemisphere winter and rising in the summer.
There is also a 2-3 month delay in the publishing of data so the 3-month average that ended in the last quarter of 2015 won't be published until February or March.
The rate of rapid increased heat accumulation in the oceans shows that the overall global energy accumulation of caused by greenhouse gasses has roughly doubled since 2004 or so.
In addition, the effect of warming is time delayed since 2/3 of the warming effect of CO2 emissions are produced by a water vapor/lapse rate feedback which doesn't kick in until accumulated atmospheric warming begins. This process takes about 10 years to reach full impact.
I believe that the reduction in sulfuric acid (SO2) emissions in South East Asia due to a severe manufacturing sector slowdown and pollution policy changes has led to an large scale increase in the warming rate over the last 2 years though this impact has been somewhat ameliorated by the massive, unprecedented fires in Indonesia as a result of the El Nino.
The regional aerosol shielding of the earth will produce a short-term shielding of the ocean from *some* of the effects of global warming this year. However, I expect that the new fourth quarter global ocean heat content data will come in somewhere around 25.2-25.5 X 10^22 joules.
This equates to around 1.2 Watts per square meter of globally averaged TOP of ATMOSPHERE global forcing, averaged over the entire surface of the earth.
Further economic slowdowns, reductions in aerosols and the water vapor/lapse rate response will ensure a rapid period of warming into a new equilibrium state with record high temperatures averaged over the entire surface of the globe, with regional anomalies, like the current Scandanavian cold spell that is likely impacted by a slowdown of the Atlantic Meridional Overturning Circulation.
You can review my work here: (image attached)