Leek investigations

Biology came third in my sciences, but this looks interesting.

Leeks to the rescue

SIR – Earlier in the year, Professor Steven Chu, America’s Energy Secretary, suggested that the roofs of houses should be painted white to combat global warming (report, May 28).
A more effective way would be to introduce the houseleek (Sempervivum tectorum) to suburban roofs. These plants, of the Crassulaceae family, capture carbon dioxide at night and use it during the day – a method of photosynthesis known as crassulacean acid metabolism.

Now, how one configures roofs to sustain the load, maintain ('acid' being a word that sets up some red flags) and manage the crop is a whole new ball of enviROI, but if the claim is true it seems at first blush a better plan than some.