The Blytt-Sernander classification of climatic periods defined, initially, by plant remains in peat mosses, is now being explored currently by geologists working in different regions studying sea levels, peat bogs and ice core samples by a variety of methods, with a view toward further verifying and refining the Blytt-Sernander sequence.
Climatically, the Holocene may be divided evenly into the Hypsithermal and Neoglacial periods; the boundary coincides with the start of the Bronze Age in Europe.