Some 500 years ago the great Japanese warrior-poet Ota Dōkan built a castle on the marshy fringes of what is today Tokyo Bay. A bustling little town sprang up, and Ota wrote:
The abode of mine
Adjoins a pine grove
Sitting on the blue sea
And from its humble eaves
Commands a view of soaring Fuji.
Today Ota Dōkan's poem is remembered more in sorrow than anything else. His beloved town has mushroomed into the world's most populousand most pollutedcapital, home to 11.4 million gasping people. The fabled pines are suffocating from smog. The blue sea is washed by tons of noxious...