The planet is getting warmer day by day. Most climatologists regard the final decade of the twentieth century as the warmest in the past millennium. Even minor alterations in global temperature will trigger a series of weather extremities and alter the climatic patterns of the planet. Global warming effects on earth are caused by several factors. To understand the overall effects of global warming on earth, we have to understand the contributions and effects of each component of the planet. The gases produced from vehicles, power plants and other sources are building up in the atmosphere, acting like a thick blanket over our planet. It has been clearly identified that additional effective technologies are needed to control CO2 in the atmosphere. In the current study, absorption of CO2 is achieved in a petrol engine using modified ZSM5. The reduction of CO2 by absorption on Cu-ZSM5 and Li-ZSM5 are compared.