Terraforming... here!

from Economist.com citie Guide...

Pollen plea

Those who are bemused by financial penalties for water conservation may also be surprised by Tokyo's decision that it has too many trees. From early February to late spring, the capital’s growing number of hay-fever sufferers endure an annual onslaught of cedar pollen. The pollen is coming earlier, which meteorologists blame on climate change and a spate of warmer summers. And there is more of it too, because Japan’s forests are slowly expanding. These forests are the legacy of a reforestation drive following the second world war, which did not take account of the allergenic properties of the fast-growing cedar tree.

So, on the insistence of its hay-fever-struck governor, Shintaro Ishihara, the metropolitan government is hitting back. It has begun asking the nose-running, eye-watering masses to donate ¥1,500 ($13) each to a project that would see 1.8m cedar trees felled in a forest west of Tokyo. These trees would then be replaced with a species that produces less pollen.

hmmm what tree to plant? Whichever they choose there will be some unforseen side-effect.