In tightly-packed cities with a distinct lack of trees such as Tokyo, planting trees on the roofs of buildings is a common practice. In fact, every new medium-sized building in Tokyo is required to plant gardens on the roof. The problem? Soil is heavy and dense. The solution? Have a brewery invent a new fake soil, of course.

Yeah, since regular soil wasn't really working out that well, Suntory, maker of whiskies, beers and many other fine beverages, developed a new synthetic called Pafcal that's lighter and more solid. Less than half as much Pafcal than soil is needed to sustain plant growth, and a tree grown in the stuff can reduce the surrounding temperature by as much as 18 degrees Fahrenheit. And with treeless cities increasingly suffering from the "heat island" problem with temperatures much higher than the surrounding areas, that'll really make a difference. [Physorg]