The oil and gas industry has often been blamed for its major contribution to greenhouse gas releases and designated as a target to knock down by media, activists, and environmentalists. It is true to say that without Oil and Gas Industry, anthropogenic emissions of CO2 and CH4 would be much lower. Similarly, it is also true to state that without this industry and petroleum products, our life standards would be much different than the current standards. One should not confuse an activity which generates greenhouse gases, and the effect of product consumption. Evaluating the real routine emissions of the oil and gas industry on the same mode than every other industry is possible and constitutes the objective of this work. As a preliminary result, however, data coming from the Environmental Protection Agency (EPA) clearly highlight that oil and gas production accounts for at least less than 10% of the greenhouse gas emissions from the energy sector in the United States. To more precisely evaluate these emissions, this study relied on environmental impact reports in terms of greenhouse gas emissions, which are available for every production site in the U.S, as well as the oil and gas consumption in the US over the year 2015. Emissions happen during three different stages of the hydrocarbon production; extraction, flaring and venting, and fugitive emissions. The importance of each stage in terms of emissions is extremely variable, depending on the quality of the oil, the field location, and the existence of an outlet for the produced gas. The greenhouse gas emissions contribution from the Oil and Gas industry is 3% for extraction, and about 0% for flaring and venting, and 0% of fugitive emissions in the US. The remaining U.S greenhouse gas emissions while processing petroleum products are due to refining at 88%, and transportation at 9%. However, these results are extremely different for Canadian oil sands, Venezuela heavy oil, Arabian light oil, or Indonesian gas condensate. Worldwide, greenhouse emission source for petroleum industry are 10% for extraction, 19% for flaring and venting, 6% of fugitive emissions, 4% of transport, and 61% of the refinery. As a result, 3.5% of greenhouse gases emitted while processing petroleum products are due to Oil and Gas industry. Based on these results, an extrapolation to the worldwide Oil and Gas production enable to assess the participation of this industry to total emissions. Results show that less than 3 % of worldwide greenhouse emissions comes actually from Oil and Gas industry.