Globally Extended Kppen-Geiger climate classification and temporal shifts in terrestrial climatic types

Increasing awareness of the impacts of global climate change on marine ecosystems and concerns about shifting bioclimatic and agricultural zones necessitate a reassessment of the geographical distribution of Earths climate types. In recent years, the availability of truly global data-sets has allowed for the application of climatic types, including the Kppen-Geiger system, over the oceans. This research uses NCAR Reanalysis data to create a global Extended Kppen-Geiger climate classification, including the world ocean, for the 1981-2010 averaging period. The percentages of Earths surface covered by tropical rainforest (Af), tropical monsoon (Am), and (especially) the mesothermal-mild summer (Cfc) climate types are much larger than in the terrestrial only analysis. Expanding and contracting terrestrial climate zones are also identified based on the differences in the total area through comparison with maps produced for 1901-1925, 1926-1950, 1951-1975, 1976-2000 and model-output-based predicted Kppen-Geiger types for 2076-2100. Results suggest that hot desert (BWh), hot semi-arid (BSh), and Af climatic types are projected to expand, while the tundra and most mesothermal and microthermal types will decrease in area. These results assist in projecting global impacts of climatic change.