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In aviation industry, weather forecast is necessary to avert air disasters if flight must take place. In the crude oil producing sectors, there is a need also for a perfect knowledge of anticipated gaseous emissions from associated natural gas of known composition being flared on daily basis through combustion activities under several operating conditions. This will help in the control of gaseous emissions from these flares and thus in the protection of their immediate and distant environment against environmental degradation via air pollution. It is in the light of this that a theoretical model employing a set of material balance equations was investigated with natural gas of Nigerian origin as combustibles using a developed computer program. Operating conditions favouring complete combustion generate the least gaseous emission specie (CO 2 only) while those that favour incomplete combustion and high temperature produce CO, NO, and NO 2 as additional species if the natural gas contains no sulphur compounds. In the presence of H 2 S, SO 2 is released in addition. The presence of other impurities, which are combustibles in the natural gas, might likely change these entirely. There is a strong correlation between emission quantity and amount of natural gas available for combustion. Carbon contents of the natural gas plays a prominent role in determination of quantity of air requires for combustion. This in turn determines the combustion reaction type (complete or incomplete). On the average, anticipated gaseous emission from natural gas of Nigerian origin with annual flaring rate of 25838.35 m 3 is predicted by the model to be 1.72×10 5 , 5.48×10 5 , 1.611×10 5 , 2.252×10 5 , and 1.16×10 3 kg for CO 2 , CO, NO, NO 2 , and SO 2 respectively. Confirmation of the presence of these gaseous pollutants from the various combustion reaction types investigated coupled with their overall high emission concentrations predicted are considered enough reasons for Nigerian Government to review its present natural gas policy. Routine flares in the country should be minimised for gaseous emission reduction.

Vehicular emissions portend high risk to human health especially to inhabitants of highway environment. However, there is paucity of information on the inventory of air pollutants on Nigerian highways. Therefore, this study aimed at estimating the ground level concentrations of emissions associated with road traffic in the Ogbomoso-section of Ibadan-Ilorin highway. Three sampling locations (Idi-oro, General and Aroje) were selected within the Ogbomoso section of Ibadan-Ilorin highway for this study. Data collections on criteria air pollutants [carbon monoxide (CO), nitrogen monoxide (NO) and sulphur dioxide (SO2)] and total suspended particle (TSP) were made within dry and wet seasons. The results of predicted concentrations of CO, NO, SO2 and TSP ranged between 0.59-352.60, 0.28-213.40, 0.04-33.40 and 0.02-14.20 µg/m3, respectively. All the predicted concentration values of selected pollutants meet-up with the regulatory standards. This study has provided baseline inventory for criteria air pollutants in the Ogbomoso-section of Ibadan-Ilorin highway.

The sections in this article are 2.1 Introduction 2.1.1 Energy Sources 2.1.2 Hydrocarbon Destruction in Gas Flares 2.2 A Review of Global Warming Concept 2.2.1 Water Vapor 2.2.2 Carbon Dioxide 2.2.3 Methane 2.2.4 Nitrous Oxide 2.2.5 CFCs 2.3 Fundamentals of Natural Gas Combustion 2.4 World Natural Gas Reserves, Production, Consumption and Destruction 2.4.1 World Natural Gas Reserves 2.4.2 World Natural Gas Production 2.4.3 World Natural Gas Consumption 2.4.4 World Natural Gas Destruction 2.5 Global Warming Contribution from Natural Gas Combustion 2.5.1 Global Warming Contribution from Natural Gas Combustion in Energy Consumption 2.5.2 Global Warming Contribution from Natural Gas Combustion in Flaring Activities 2.6 Control Measures for Global Warming from Natural Gas Combustion 2.7 Conclusion Keywords: global warming; climate change; natural gas; combustion; gas flares