Study on the association of green house gas (CO2) with monsoon rainfall using AIRS and TRMM satellite observations

• Monthly, annual averaged CO2 over Indian–Indonesian region show high CO2 in Northern plains and in the summer (May–June).
• The percentage increase in rainfall is not in direct proportion to the increased carbon dioxide concentration.
• Study of CO2 and rainfall anomalies and the association with ENSO. ENSO appears to be exerting much influence on rainfall.

Monsoon water cycle is the lifeline to over 60 per cent of the world’s population. Throughout history, the monsoon-related calamities of droughts and floods have determined the life pattern of people. The association of Green House Gases (GHGs) particularly Carbon dioxide (CO2) with monsoon has been greatly debated amongst the scientific community in the past. The effect of CO2 on the monsoon rainfall over the Indian–Indonesian region (8–30°N, 65°–100°E) is being investigated using satellite data. The correlation coefficient (Rxy) between CO2 and monsoon is analysed. The Rxy is not significantly positive over a greater part of the study region, except a few regions. The inter-annual anomalies of CO2 is identified for playing a secondary role to influencing monsoon while other phenomenon like ENSO might be exerting a much greater influence.