A French consultancy called the Ginger Group has proposed a scheme that would cover the Eiffel Tower in greenery, ostensibly motivated by increasing levels of air pollution in Paris.
Not to play the Grinch here, but the inherent wind loads on the structure — combined with the amount of soil needed to nurture such plants — would make their plan a tough one to sustain for more than a few weeks. The group says they want to convey the city’s newfound commitment to sustainability (stuffy old monument to mechanical ingenuity cramping your new "sustainable" image? Cover it in trees!). The weight of the plants would total around 400 tons. They’d install an irrigation system, and even blanket the greenery in lights so that the Tower could still "sparkle" Unfortunately, as those of you who spec green walls or roofs knows, the task of keeping these plants alive can be quite cost and time intensive, depending on the situation. Indeed, the Ginger Group says the installation alone would cost about $100 million dollars.
As many commenters are pointing out, high winds would probably contribute to soil erosion, leading to an Eiffel Tower covered in dead, brown ferns. Then again, green wall technology improves every year.
Below, an infographic produced by the group: