@ChuckMcManis
I'm afraid you don't have the facts right. The Pliocene started about 4 deg C warmer than today and ended cooler than today. The so-called mid-Pliocene warm period likely was about 3 deg C warmer, globally. The Pliocene saw a cooling trend throughout. CO2 remained below 400 ppm, less than today. There is no mechanism that would lead us to expect rapid (century-scale) warming spikes. It's also not true we don't have records. We have good d13C and dO18 time series.