By Dr Nityanand Singh and Ashwini Ranade
The authors are Head, Climatology and Hydrometeorology Division, IITM, Pune and Research Associate, IITM, Pune respectively.
Understanding climatic changes of the Holocene Period (past 11,000 years) is crucial to assess the impact of global warming on the Indian environment. In the following discourse we provide an overview of climatic changes over the Indian subcontinent based on instrumental records (1813-2008 AD) and as reported by historians (600 BC-1800 AD), archaeologists (3000–600 BC), mythologists (8,000-3,000 BC) and palaeo-climatologists (prior to 8,000 BC).
Vedic Period During last glacial period (110,000-11,000 years before present or BP) it appears that even Lower Himalaya was covered with ice and snow. The glacial period ended around 11,000 BP and in the following 1,000 years the near surface temperature of the northern hemisphere rose from 11°C to 15°C. From glacier/ice/snow melts rivers flowed through northwest India - one of them being the Sarasvati. Originating near Shimla (Himachal Pradesh) Sarasvati flowed through present day Punjab, Rajasthan and Gujarat (parallel...