Climate models are accurately predicting ocean and global warming
For those of us who are concerned about global warming, two of the most critical questions we ask are, how fast is the Earth warming? and how much will it warm in the future?.
The first question can be answered in a number of ways. For instance, we can actually measure the rate of energy increase in the Earths system (primarily through measuring changing ocean temperatures). Alternatively, we can measure changes in the net inflow of heat at the top of the atmosphere using satellites. We can also measure the rate of sea-level rise to get an estimate of the warming rate.
Since much of sea-level rise is caused by thermal expansion of water, knowledge of the water-level rise allows us to deduce the warming rate. We can also use climate models (which are sophisticated computer calculations of the Earths climate) or our knowledge from Earths past (paleoclimatology).
https://www.theguardian.com/environment/climate-consensus-97-per-cent/2016/jul/27/climate-models-are-accurately-predicting-ocean-and-global-warming