Green groups say the weather data is evidence of the city's worsening air pollution Hong Kong's skies have been obscured by haze or smog for a record number of hours in 2006 - totalling about a third of the year, weather figures indicate. The year is also set to be one of the hottest and greyest years on record, unless extraordinary temperatures and hours of sunshine are recorded over the next week. Environmental groups have seized on the weather figures as further evidence of worsening air pollution in Hong Kong and are calling for stricter and more binding controls on emissions. But the government says most air pollution measures are improving and its existing and planned emission reduction actions - including an emissions agreement with Guangdong - will see air quality improve further. Figures also showed the number of days the air-pollution index was at a high level this year was the same as last year. In the first 11 months of the year alone, visibility at the airport was reduced to less than 8km for 2,617 hours, exceeding the annual total for last year by 7.3 per cent and up by 172 per cent since 1997, Hong Kong Observatory figures show. The average temperature for the year up to December 20 is 23.5 degrees Celsius, which would make this year tie as the eighth hottest on record since 1885. There were only 1,698 hours of bright sunshine over the same period. But visibility at the observatory in Tsim Sha Tsui has improved in the past year, with 1,179 hours of reduced visibility in the first 11 months of the year, compared with 1,416 hours in the same period last year. The number of days up to December 20 with an air-pollution index of more than 100 at any station in the city was 49, the same number as for the whole of last year. Friends of the Earth acting director Edwin Lau Che-feng said: 'The record hours of reduced visibility in 2006 show that air pollution has got worse in Hong Kong. Particulates and sulfur dioxide are the basic ingredients that generate smog or haze. Our city is choking in smog and the inhabitants of Hong Kong are breathing air that could harm their health.' He called on the government to set specific annual emission targets for power stations, and require commercial firms to replace old diesel-powered vehicles with new ones that conformed with the latest Euro IV emission standards. Lister Cheung Lai-ping, chief executive of the Conservancy Association, said: 'The situation is alarming. These are strong signs that global warming is affecting the city's weather. But the worst is that we are not going to see significant improvements in the near future.' A spokeswoman for the Environmental Protection Department denied that an increase in reduced visibility hours was due to worsening air quality. 'Visibility is affected by many factors,' she said. 'We have not observed a deterioration of suspended particulate levels or air pollution levels in 2005 and 2006.' Other measures of air quality had improved over recent years. The hours in which the roadside air pollution index exceeded 100 had been reduced by 56 per cent and levels of respirable suspended particulates by 36 per cent from 1999 to last year. 'Only sulfur dioxide has seen an increase in the last few years owing to the increase in emissions from power plants,' she said. 'We have imposed emission caps on power companies since 2005. These emission caps will be progressively tightened in the future,' she said. The government was also working with Guangdong to reduce emissions across the region by 2010 and for the replacement of older diesel vehicles with those that comply with Euro IV emissions standards, she said. The department considered 'the current incentive model to be the best approach'. 'We are confident that emission reduction measures introduced in the past and measures planned for the future will improve our air quality.'