The Impacts of Climate Change in Atmospheric CO2 Emission, An Air Transportation Case Study

IntroductionThe largest growth in GHG emissions has come from energy supply, transport and industry, while residential and commercial buildings, forestry (including deforestation) and agriculture sectors have been growing at a lower rate (IPCC,2007). Aviation’s contribution to climate change is now a topic of considerable interest. Aviation is a comparatively small contributor – a few per cent – to Greenhouse Gas (GHG) emissions, but its growth is rapid (Broker, 2008). Emissions of carbon dioxide by aircraft is about 2% of total anthropogenic carbon dioxide emissions in 1992 or about 13% of carbon dioxide emissions from all transportation sources (IPCC, 2007). Therefore, it seems that fuel management in aviation has important role to CO2 emission. This paper focuses on the estimation of consumed amounts of fuel and CO2 emitted to the atmosphere in a case with incorrect fuel management.Material and MethodsAll information about the number of flights to Abadan and Ahwaz airports, including QRF and Diverted flights are received from Tehran Area Control Center (ACC). Meteorological data are provided by Iran meteorological organization (IRIMO) including the number of dusty days and is compared with long time (20 years) average number. Distance of a specified flight rout from departure aerodrome to the over head of the destination aerodrome, is measured according to Tehran FIR map which is the flight distance in going route. Then, the distance is doubled for QRF flights to include return to departure airport. In divert flights, the distance of a specified flight rout from destination overhead to alternate airport is marked and measured using Tehran FIR map. All flights to Ahwaz and Abadan destinations considered in this paper are T154 and F100 aircrafts with speeds of about 840km/h (420knot). Their air speed can cover a distance of 14 km (7 nm) per minute. So, flight timing in cruising phase can be easily computed using flight speed and distance. On the other hand, times for take-off and landing should be determined to compute the real total flight timing. With an optimistic view, 8 minutes are considered for takeoff and landing time in each flight. The amount of consumed fuel is 33 liter/ minute for a 2 engined F100. It is clear that this amount should be more for T154 with 3 engines and is about 83 liter/minute.. The consumed fuel after starting up for taxi and take off and also after landing and taxi to apron is not considered.Several studies have been done to calculate CO2 emissions considering consumed fuel, load factor, aircraft speed and so on. One way to calculate CO2 emissions is using fuel consumption per flight. The CO2 emissions takes values of about 250 kg (i.e. 1/4 tone) per hour of flying. In order to have a comparison between atmospheric conditions effective on flights in summer of 2009 compared to similar atmospheric conditions in earlier past years and the number of all days with low visibility due to dust is compared with long term (20 years) average number. The same comparison has been done for the number of days with visibility less than minimum visibility required for Ahwaz and Abadan airports, considering aircraft type.Discussion and resultsDuring June and July 2009, 22 flights had been QRF (Quick Return Flight) or diverted due to poor visibility in Abadan and Ahwaz airports. In this matter, not only financial losses are inflicted relevant airlines due to futile consumed fuel, but also lots of CO2 were pushed into the atmosphere which is considered a pollution threat to the environmental.Minimum visibility required for landing in the Ahvaz airport is 1200 meters. This parameter is 2400 and 2700 meters for T154 and F100 respectively in the Abadan airport.A climatology survey shows that the dusty days number are more than 20 and 25 respectively in June and July 2009 in the Khuzestan province(including Ahwaz and Abadan airports). Focusing on the days with minimum visibility in Ahwaz and Abadan airports during June and July 2009, relevant maps shows strong deviations from long term mean values. Indeed, dusty days are 8, 12 and 15 days more than mean long term (20 years) in June and July 2009 with visibility less than 1200, 2400 and 2700 meters respectively. The calculated values show that 134,500 liters of aircraft fuel has been consumed futile where its financial value cant be omitted. Besides that property loss, the amount of emitted CO2 into the atmosphere is about 8,000 kg reminding that the time for landing and takeoff is considered 8 minutes which is very optimistic. Although the amount of consumed fuel and emitted CO2 is not comparable with global scales but it is noticeable that the energy, time and money were used pointlessly and with a suitable management it could be prevented.ConclusionsThis paper is dealing with transportation and environment related subjects from two viewpoints. First, resources of energy can be conducted in a correct manner under a skillful management system. In this regards, financial savings can be satisfactory revenues. Second, adaptation to climate change is acquired which is an available solution to deal with natural events that are not in human control. Results of this study, shows that with more conscious consideration of issued meteorological warnings for in order to cancel flights or change the time of departure (based on meteorological warnings, financial loss can almost be prevented. In addition, emission of CO2 and as a result, environmental pollutions is controlled.Climate change is an obvious and unavoidable phenomena and its occurrence is approximately uncontrollable. Adaptation to climate change is a solution to reduce losses. If flight time is transferred from early morning to midday, the landing would take place because of improved visibility due to the surface heating. On the other hand, if the low visibility conditions (dusty days) continue in future years, it is necessary to equip the airports with those instruments which have more capabilities for aircraft landing in low visibility conditions. In this case, there wouldn’t be any QRF, divert or even cancelled flight due to poor visibility. Of course, it needs more study and is not considered in this paper.