The Holocene Climate Optimum (HCO) was a warm period in the first half of the Holocene epoch, that occurred in the interval roughly 9,500 to 5,500 years BP, with a thermal maximum around 8000 years BP. It has also been known by many other names, such as Altithermal, Climatic Optimum, Holocene Megathermal, Holocene Optimum, Holocene Thermal Maximum, Holocene global thermal maximum, Hypsithermal, and Mid-Holocene Warm Period.
Medieval Warm Period (MWP), also known as the Medieval Climate Optimum or the Medieval Climatic Anomaly, was a time of warm climate in the North Atlantic region
warmest period of the Holocene, the Atlantic is often referenced more directly as the Holoceneclimaticoptimum, or just climaticoptimum. The Atlantic is