Owen Jennings: A new angle on an old topic

Do you remember the bad old days, flying out of Los Angeles and suddenly passing through that brown gunge ceiling, looking back and thinking, “heck, was I breathing that stuff?” It's heaps better now.

I recall being at a conference in Taipei on a cloudless day and being unable to read signs on the buildings across the street because of the excessive air pollution. Taiwan spent hundreds of millions to improve their factory emissions, and it worked. Their atmosphere is much cleaner now.