The mid-Piacenzian warm period (3.264 to3.025 Ma) is the most recent geological period with present-like atmosphericpCO2and is thus expected to have exhib-ited a warm climate similar to or warmer than the present day.On the basis of understanding that has been gathered on theclimate variability of this interval, a specific interglacial (Ma-rine Isotope Stage KM5c, MIS KM5c; 3.205 Ma) has beenselected for the Pliocene Model Intercomparison Projectphase 2 (PlioMIP 2). We carried out a series of experimentsaccording to the design of PlioMIP2 with two versions ofthe Institut Pierre Simon Laplace (IPSL) atmosphere–oceancoupled general circulation model (AOGCM): IPSL-CM5Aand IPSL-CM5A2. Compared to the PlioMIP 1 experiment,run with IPSL-CM5A, our results show that the simulatedMIS KM5c climate presents enhanced warming in mid- tohigh latitudes, especially over oceanic regions. This warmingcan be largely attributed to the enhanced Atlantic MeridionalOverturning Circulation caused by the high-latitude seawaychanges. The sensitivity experiments, conducted with IPSL-CM5A2, show that besides the increasedpCO2, both mod-ified orography and reduced ice sheets contribute substan-tially to mid- to high latitude warming in MIS KM5c. Whenconsidering thepCO2uncertainties (+/−50 ppmv) duringthe Pliocene, the response of the modeled mean annual sur-face air temperature to changes topCO2(+/−50 ppmv) isnot symmetric, which is likely due to the nonlinear responseof the cryosphere (snow cover and sea ice extent). By an-alyzing the Greenland Ice Sheet surface mass balance, wealso demonstrate its vulnerability under both MIS KM5c andmodern warm climate