According to a recent article in the New York Times on “The Allure of Vertical Forests,” cities currently cover about 3% of the Earth’s land. However, some forecasts say that population growth and migration could push that proportion up to about 10% by 2030. And it’s pretty certain that almost all of that will go into sprawl of existing urbanization over surrounding woods and fields. No amount of vertical forests or inside gardens, no matter how good, can compensate for the loss of such green space and arable land.

So what is the possibility of building new cities – including vertical forests – in marginal lands where food crops and shade trees aren’t otherwise so easy to grow? Even in the middle of the Sahara – perhaps surrounded by expanses of solar panels and wind turbines, and pools of desalinated water, if we are to accept the feasibility of some schemes?

The vertical forest, which is the idea of architect and urban planner Stefano Boeri, is actually intended to help offset some of the intense use of resources and production of carbon dioxide in urban centers – while improving the living environment for people. Such towers have been built in or conceptualized for existing cities, each project unique to its location.

It is interesting to note that Boeri has also developed a conceptualization of vertical forests in domed cities on Mars. Readers of this blog may recall my contention two years ago that schemes for settling Mars – whether or not they will ever be realized – should at least be prefaced by experience with new cities in Earth’s harshest deserts. In that post, I highlighted another concept by OXO Architectes for a tower city designed specifically for the Moroccan desert.

So on a very Earth-bound, practical level, should we encourage more green tower concepts for new cities in deserts like the Sahara – concepts that could in effect help “green the desert” through sustainable urbanization?