A clear blue sky in Beijing, a rare sight during the smog season, for the past few days has been waiting to greet delegates to the Asia-Pacific Economic Cooperation meeting. City residents have given it a name: "APEC Blue".

A series of environmentally friendly measures have been taken to reduce the Beijing smog by cutting emissions by 30-40 percent during the APEC meeting, including limiting the number of cars on the road, granting leave to people working in certain types of institutions and suspending production in factories. However, whether these measures will be implemented in the long term remains to be seen.

Perhaps we can learn something from London, where the Great Smog killed 4,000 people in four days in 1952. Britain then passed its first air pollution act, which stipulated that all power plants in London should be shut down, factories must build taller chimneys, and the heating system must be improved. Only with the integrated efforts of multiple sectors can the "APEC Blue" be transformed in a permanent "Beijing Blue".

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