London - Sitting in a quintessentially English country garden under an azure sky and listening to the springtime activity of birds busily building their nests in time for the mating season, it is fair nigh impossible to believe that thousands of feet above us lies a noxious cloud of fine particles capable of downing the world's most advanced airliners.

However, that is the reality for my Chinese girlfriend and I. She, some 6,000 miles from her familiar environment, was enjoying a first vacation outside her homeland and now is bewildered and worried by a turn of events none could have predicted and with no resolution in sight. Despite the un-seasonal sunny weather, a metaphorical chill wind is blowing across the land.

We are staying with friends midway between the Heathrow and Gatwick flight paths. They tell me airplanes normally pass every 30 seconds or so during the day. Since Thursday, the skies, songbirds aside, have been eerily quiet. No vapor trails vie with natural clouds to daub the firmament with wisps of white. Those with a vivid imagination could be forgiven believing this is the prelude to a drama on a cosmic scale. It is indeed a very strange experience.