Hot? Give Tokyo a cool bath

Brows are furrowing all over the place about Tokyo's "heat island"--temperatures in the metropolis can get up to 10C hotter than the suburbs due the concentration of buildings, airconditioners, and traffic--and one of the solutions being suggested recently, in various forms, is water cooling. The idea is that you dribble enough water over a surface to form a thin, even film, and evaporation will go to work and cool things down.

This is all fine and good and, if rainwater is used, ecologically sound. Reporting the sensible and hard-headed is not, however, what dottocomu is about. No, what has caught my eye is the "O-Edo Uchimizu Daisakusen"--the "Great Edo Water Sprinkle," we might call it. On August 25, the plan goes, a million people who saved the bathwater from the night before will sprinkle at least six litres of it on the ground outside their houses, and collect the before-and-after temperature data. The theory is that six litres x a million people will cool the capital down roughly 2C.

If the number of participants registered at the website (Japanese) is anything to go by, however, the scheme is heading for an epic failure. 344 were signed up yesterday afternoon, and the number is up to 433 now. Unfortunately the impression from a quick scan of the listings is that a good third of these are either double or triple registrations or eager idiots from the far-flung suburbs--in the extreme cases, from as far afield as Fukuoka and Osaka.

However, all is not yet lost. This weekend sees the all-important publicity stunts at Odaiba and the O-Edo Onsen theme park, both of which are a dead cert to be featured on the TV news. This, rather than the Internet, is probably the more realistic way to advertise, given that uchimizu is a practice with overtones of pre-airconditioner times, and as such is likely to appeal more to the older and most definitely offline sections of the populace. Whether these folk will be dedicated enough to send in their temperature data and whatnot is another matter, though. Another potentially positive factor to consider is that August 25 is a weekday and the school summer holidays are just about ending as I write, so idea-strapped science teachers throughout the capital will undoubtedly be planning to drag their charges into the playground for a bit of "science is fun" propaganda.

If the results of this experiment are dramatic enough, it won't be long before someone comes up with a gadget that enables effort-free dumping of one's old bathwater onto the street outside. Let's hope the neighbours like the smell of herbal bath gunk.

The biggest enemy of this project, though, may turn out to be timing; summer came extremely late and looks to have lasted about three days this year, so by August 25 it may be cool enough that no-one can be bothered to schlepp buckets of water outside.