Solar irradiance, climatic indicators and climate change - An empirical analysis

Since the Sun is the main source of energy for our planet therefore even a slight change in its output energy can make a huge difference in the climatic conditions of the terrestrial environment. The rate of energy coming from the Sun (solar irradiance) might affect our climate directly by changing the rate of solar heating of the Earth and the atmosphere and indirectly by changing the cloud forming processes. In the present paper, based on stability test of Vector Auto Regressive (VAR) model, we have used the impulse response functions and the variance decomposition method for the analysis of climate variability. We have examined the possible connections among the solar irradiance and some climate indicators, viz., the global temperature anomaly, the global mean sea level, the global sea-ice extent and the global precipitation anomaly occurred during last forty years (1978-2017). In our investigation, we have observed that the impact of solar irradiance on the global surface temperature level in next decade will increase by similar to 4.7% while the global mean sea level will increase about 0.67%. In the meantime, we have noticed about 5.3% decrement in the global sea-ice extent for the next decade. In case of the global precipitation anomaly we have not observed any particular trend just because of the variable climatic conditions. We also have studied the effect of CO2 as anthropogenic forcing where we have observed that the global temperature in the next decade will increase by 2.7%; mean sea level will increase by 6.4%. Increasing abundance in CO2 will be responsible for about 0.43% decrease in the sea-ice extent while there will not be any change in the precipitation pattern. (C) 2019 COSPAR. Published by Elsevier Ltd. All rights reserved.