Impacts of Global Warming and Stratospheric Geoengineering on the Changes in Surface Air Temperature and Precipitation Over India

Abstract:

In this study, the effects of global warming and stratospheric geoengineering on temperature and rainfall variability over India is assessed using Pi-Control, Representative Concentration Pathways 4.5 (RCP4.5) scenario and stratospheric geoengineering scenario (G3) simulations. We have used multi model mean (MMM) of five global climate models for 51 years (2020-2070) included in the Geoengineering Model Inter comparison Project (GEOMIP). The changes in surface air temperature and precipitation during the seasonal mean of December-February (DJF), March-May (MAM), June-August (JJA) and September-November (SON) are examined over Indian land region. It is found that changes in MMM (CMIP5 RCP4.5) seasonal average surface air temperature show severe warming of 2 to 4 °C in most parts of India for 2020-2070 with respect to the piControl and the warming in DJF and MAM is relatively higher than that in JJA and SON, but in response to the geoengineering i.e. G3-piControl, over cooling would happen over the Indo Gangetic plains and Foot Hills of Himalaya in all the seasons. Considerable residual warming would still persist over the northernmost part of India throughout the year and over south of Indo-Gangetic plains in DJF, MAM, and SON. Further, in DJF and MAM significant decline in precipitation is observed with respect to the RCP4.5 scenario and in JJA and SON significant enhancement in precipitation is observed; whereas, in response to geoengineering, in DJF a substantial reduction in precipitation and in JJA and SON a substantial increase in precipitation is observed.

Key Words: Climate Change, global warming, stratospheric geoengineering, global climate model