Government officials monitoring air pollution in the Pearl River Delta have had to move the goalposts for pollution reduction after estimating that emissions levels in 1997 were twice as high as had been thought.
The Pearl River Delta Air Quality Management Plan review said particulates emission in the delta region in 1997 was 520,000 tonnes, more than double the 245,000 tonnes previously estimated.
A 40 per cent underestimation in sulfur dioxide and nitrogen oxides emissions were also found in the review. As a result, emissions data from 1997 that serve as a baseline for measuring progress towards reducing pollution have been raised, according to the review paper.
As the 1997 data had been underestimated by as much as 112 per cent in the case of particulates, changes to the baselines would have a big influence on determining how far the region was from achieving emission reduction targets.
In 2002, Hong Kong and Guangdong province agreed to pursue pollution target cuts of between 20 and 55 per cent in four major pollutants by 2010 from 1997 levels.
By underestimating the baseline emissions, the extent of emission reductions required by 2010 would be smaller, making it easier to achieve the targets. Overestimates, however, meant more efforts were needed.
