Abstract:
Changes in precipitation, air temperature, and model simulated soil moisture were examined for the observed (1950-2008) and projected future (2010-2099) climate for the sowing period of Kharif and Rabi [(KHARIF_SOW (May-July) and RABI_SOW (October-December)], and the entire Kharif and Rabi [(KHARIF (May-October) and RABI (October-April)] crop-growing periods in India. During the KHARIF_SOW and KHARIF periods, precipitation declined significantly in the Gangetic Plain, which in turn resulted in declines in soil moisture. Statistically significant warming trends were noticed as all-India averaged air temperature increased by 0.40, 0.90, and 0.70 °C in the KHARIF, RABI_SOW, and RABI periods, respectively during the period of 1950-2008. Frequency and areal extent of soil moisture based droughts increased substantially during the latter half (1980-2008) of the observed period. Under the projected future climate (2010-2099), precipitation, air temperature, and soil moisture are projected to increase in all the four crop-growing seasons. In the projected future climate, all-India ensemble mean precipitation, air temperature, and soil moisture are projected to increase up to 39% (RABI_SOW period), 2.3 °C, and 5.3 %, respectively in the crop-growing periods. While projected changes in air temperature are robust across India, robust increases in precipitation and soil moisture are projected to occur in the End (2070-2099) term climate. Frequency and areal extents of soil moisture based severe, extreme and exceptional droughts are projected to increase in the Near (2010-2039) and Mid (2040-2069) term climate in the majority of crop growing seasons in India. However, frequency and areal extent of droughts during the crop growing period are projected to decline in the End term climate in the entire crop growing period due to projected increases in the monsoon season precipitation.