Reconstruction of past climate of Indian subcontinent for the last 40 ka BP based on multi proxy data and correlation with global data-a review

Abstract

The contribution attempts to reconstruct the past climate of different regions of the Indian subcontinent for the last 40 ka before present (BP) on the basis of 14C dating, chemical analysis, pollen analytical studies and carbon isotope analysis(δ13C). A correlation of data from India with other global sites is also attempted. Review ofthe published data shows heterogeneous climatic conditions in different parts of India. The climate in highland regions of India especially in Ladakh, Jammu & Kashmir (J & K) and neighbouring areas was alternating from dry arid to brief ameliorations during the last 31.4 ka BP (Beyond Calibration Range (BCR)). The climate in the Gangetic plain, representing humid and subtropical climate zone, was alternating from warm humid to cool humid primarily due to changes in SW monsoon in the region during the last 40.0 ka BP (BCR). The climate in arid zones in western India especially Rajasthan and parts of Gujarat was predominantly arid with a brief wet and humid climate during the above period. In semi arid zone in Nilgiris and Palni Hill regions of south India the climate was alternating from moist humid to dry arid phase. One of the tropical wet and dry climatic zones of India namely Orissa was experiencing predominantly wet and occasional dry climate. The beginning of the Holocene warming and onset of humid phase was suggested in several climatic regions of India during 11.4-7.6 ka Cal BP. Amelioration of climate was observed in different regions during 2.0 ka Cal BP as well as during the present time. It is inferred from several proxy data from diversified climatic and geographical region.