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Following is a question by the Hon Chan Hak-kan and a written reply by the Secretary for the Environment, Mr Wong Kam-sing, in the Legislative Council today (March 27):
Question:
According to the 2010 Hong Kong Air Pollutants Emission Inventory published by the Environmental Protection Department, emissions of three types of air pollutants, namely sulphur dioxide, nitrogen oxides and carbon monoxide, from civil aviation in 2010 were higher than those in 2008. The Environmental Report 2010 published by the Civil Aviation Department pointed out that, since the adjustment of the airways for arrival aircraft from the west and the north of Hong Kong in October 2009 to shorten the travelling distances, carbon dioxide emissions from civil aviation in 2010 were estimated to have dropped by about 350 000 tonnes. In this connection, will the Government inform this Council:
(a) of the emissions of various air pollutants from aircraft in 2011 and 2012; any specific measures to reduce air pollutant emissions from aircraft movements and aircraft parking at the Hong Kong International Airport (HKIA);
(b) of the number of airways in the Hong Kong Flight Information Region at present; whether the authorities have assessed the air pollutant emissions from aircraft using various airways, and the impact of such air pollutant emissions on Hong Kongˇ¦s air quality; if they have, the assessment result;
(c) of the districts where the air pollutant emissions from aircraft have currently greater impact on the ground-level air quality; whether it has assessed the risks posed by air pollutant emissions from aircraft on the public health; if it has, of the assessment outcome;
(d) whether it knows which models of aircraft or what regions from which they come have caused more serious air pollution, and the corresponding measures taken by the authorities;
(e) whether it has assessed if the visibility in the vicinity of HKIA had been affected by air pollution caused by aircraft movements and parking in the past three years; if visibility had been affected, of the details, and the corresponding measures taken by the authorities to ensure aviation safety; and
(f) given a number of airports in the Pearl River Delta Region at present, whether the authorities of Guangdong Province, Hong Kong and Macao have jointly established a mechanism, so as to reduce air pollution caused by aircraft movements and parking in these airports?
Reply:
President,
(a) Every year, the Environmental Protection Department (EPD) publishes an annual emission inventory for Hong Kong listing out the quantities of emissions of major emission sources. On March 20, 2013, we published the emission inventory for 2011. The emission inventory for 2012 is under preparation. According to the published emission inventory, the total quantities of air pollutants emitted during the arrivals, departures and parking of aircraft at the HKIA in 2011 are set out in table 1.
Annex 16 to the Convention on International Civil Aviation, Volume 2, Part III, Chapter 2 specifies emission standards of air pollutants for commercial aircraft including smoke, unburned hydrocarbons, carbon monoxide and nitrogen oxides. All commercial aircraft operating in Hong Kong have to comply with these emission standards to reduce their emissions.
Since 2009, the Civil Aviation Department (CAD) has implemented new airways that shortened the travelling distances for arrival aircraft from the west and the north of Hong Kong to reduce the emissions of air pollutants and carbon dioxide from aircraft. During 2011, more than 63,000 flights benefited from the shortened arrival routes and it is estimated that up to 390,000 tonnes of carbon dioxide were reduced.
Since its operation, the Airport Authority (AA) has provided electricity powered fixed ground power (FGP) and pre-conditioned air (PCA) systems for aircraft at parking stands to minimise the need for aircraft to use their on-board fuel combustion auxiliary power generation units so as to reduce their emissions. About 80% of aircraft have now adopted the FGP and PCA systems. In 2014, the AA will mandate aircraft at parking stands to use FGP and PCA systems.
(b) and (c) There are currently five main airways in Hong Kong to accommodate aircraft arriving and departing at the HKIA.
In 2011, the AA commissioned the Hong Kong University of Science and Technology to analyse the correlation between the emissions from the HKIA and other areas in the North Lantau based on air quality data recorded at the air quality monitoring stations in the vicinity of the airport from March 2006 to February 2010. The analytical results revealed that exceedances of the Air Quality Objectives at Tung Chung were mainly due to ozone and respirable suspended particulates primarily caused by regional air pollution instead of emissions from the airport. Hence, the impact of emissions from the airport on the air quality of Tung Chung is not significant.
Aircraft are flying at high altitudes most of the time except during landing, take-off and taxiing that are close to the ground. Therefore, emissions from aircraft have little impact on the air quality in other districts in the region.
(d) All aircraft operating in Hong Kong have to comply with the emission standards set out in the Convention on International Civil Aviation. The total quantities of air pollutants emitted from individual models of aircraft depend on a number of factors including the numbers of their arrivals and departures in a year, the type, size and number of engines. Even for aircraft of the same model, they may not have engines of the same types or sizes and could have different quantities of emissions. In general, larger aircraft with higher arrival and departure frequencies will have greater quantities of emissions.
(e) The annual aircraft arrivals and departures at the HKIA increased by 16.8 per cent in the last five years. According to the record of the Hong Kong Observatory in the same period, the number of hours of reduced visibility recorded at the HKIA dropped from 1,951 hours in 2008 to 826 hours in 2012, down by 58 per cent. The annual averaged concentration of fine suspended particulates (PM2.5), which is closely correlated to visibility, recorded at EPD's Tung Chung general air quality monitoring station also showed a reduction of 24 per cent in the same period, from 37 ug/m3 in 2008 to 28 ug/m3 in 2012. These data show that the visibility in the vicinity of airport was not significantly affected by movements and parking of aircraft. Detailed data are tabulated in table 2.
CAD, together with the AA and aircraft operators, have put in place established procedures for air traffic control and ground operations at the HKIA under reduced visibility conditions to ensure flight safety and smooth operation. Such procedures include increasing nominal spacing between aircraft, enhancing the safeguards of navigation signals, special airfield ground light settings, closure of certain vehicular routes, etc.
(f) As mentioned in the reply to (b) and (c) above, emissions from aircraft have little impact on air quality in the region. Emission standards set out in Annex 16 to the Convention on International Civil Aviation applies to aircraft arriving at the Guangdong Province, Hong Kong and Macao for reducing emissions from aircraft movements.
Ends/Wednesday, March 27, 2013
Issued at HKT 15:25
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