Because of global warming the city is more vulnerable than ever to flooding, and this despite spending billions of dollars on an underground system supposed to control those flood waters.
In the past three decades rainfall that measures more than two inches an hour has increased 30%. It seems that global warming is to blame for these intense rains in a country that is already among one of the wettest in the world.
On top of this, rising oceans makes the Tokyo area vunerable to storm surges and yet people and industries still want to settle near the waterfront. Pumping groundwater as also led parts of the city to sink by almost 15 feet in the past 100 years, thereby increasing the risk of these storm surges.
If one adds increased rainfall with the potential for destructive earthquakes and tsunamis, Tokyo is one of the riskiest city to live in. And the risk will not diminish in the future. Add to these woes the fact that the government is now heavily in debt and has an aging population one can see the financial challenges in making Tokyo secure, now and in the future.