This study was conducted to examine the energy use pattern, efficiency, sustainability and GHG reduction potential in maize production in Karnataka State through a non-parametric production function (DEA) and threshold dynamic panel model framework. Cross-sectional panel data obtained from cost of cultivation scheme was used for the study. The results illustrated that the total input energies in maize production for the period under study increased from 73.01 thousand MJ ha-1in 2010-11 to 95.03 thousand MJha-1in 2017-18. Energy usage pattern indicated that power and electricity consumed for irrigation were the main energy inputs consumed in maize production in the study region. The farmers were technical inefficiency (0.851) implying that 14.9 per cent of the overall resources in the production process could be saved. The total CO2 emission was calculated as 45.17 thousand kg CO2 eq ha-1. By energy optimization, the total energy consumption can be reduced to 105.7 thousand MJ ha-1 corresponding to total CO2 emission reduction potential to value at 5.7 thousand kg CO2eq ha-1. Sustainability of the farm was characterized by positive growth at a low rate of 0.07% per annum and thus, higher efficiency level accompanied by high level of productivity resulted in potential reduction emission level among the farmers. It is, therefore; recommended that government policies should be geared towards practices that tend to improve efficiency and productivity of the farmers through effective extension education.