Satellite-based assessment and forecasting of greenhouse gas (GHG) concentrations in Indian megacities using advanced statistical methods.

The urgent challenge of climate change, driven by greenhouse gas (GHG) emissions, highlights the need for reliable monitoring to inform effective mitigation strategies. However, the lack of monitoring stations in India for direct GHG measurements poses a challenge. This study explores the potential of satellite data for monitoring CO and CH concentrations in Indian megacities, specifically for Mumbai and Delhi. We assessed the reliability of Orbiting Carbon Observatory-2 (OCO-2) satellite data for CO and Sentinel-5 Precursor data for CH by comparing them with ground-based Total Carbon Column Observing Network (TCCON) measurements. Additionally, we applied the Seasonal Autoregressive Integrated Moving Average (SARIMA) model for CO₂ forecasting in Mumbai, achieving high accuracy (mean absolute error = 2.1 ppm, root mean square error = 2.72 ppm). While data limitations restrict CO analysis for Delhi, the findings for Mumbai significantly contribute to understanding urban CO dynamics. The SARIMA model also shows promise for CH forecasting with MAE of 8.3 ppb (Mumbai) and 7.78 ppb (Delhi) and RMSE of 10.37 ppb (Mumbai) and 11.92 ppb (Delhi). These findings underscore the utility of satellite data and forecasting models in monitoring urban GHG emissions. The observed rise in CO and CH concentrations highlights the urgency of implementing serious actions to address climate change.