In the future, I expect my cities to have trees.  You may or may not have thought about this expectation, and you may or may not agree.  But if you do, there are many actions required to ensure that future cities have trees.

This may not be on your radar of urgent environmental issues in the current political climate.  But our long-term future cannot be driven only by urgency.  We have to act out of aspiration too.  In the short term (0-20 years) that means fighting ridiculous vandals who cut down trees; prioritizing keeping trees alive during our long California drought (or your local climate calamity); and supporting local ordinances that protect old trees and forests. It means valuing their natural and economic benefits.  In the long term (50-200 years) it means re-imagining human habitats such that trees can thrive alongside, above, below, and within them.  I want my arcologies and mega-structures and futuristic dwellings on earth and in orbit to learn from and incorporate trees.  Tall trees!

You may now drop the needle on this post’s eponymous sound track, “Tall Trees” by Crowded House.

Let’s start by looking at some actual tall trees for inspiration…  Hyperion!  The world’s tallest, my neighbor up the coast. How tall? 115.5m tall.

Stunning.  It reminds me a little of this contender for a tower in Beijing’s Olympic park: soaring above everything around it. Top heavy and surreal, unlike the classic redwood-inspired building, the Transamerica Pyramid.

Of course it has taken a century of hard work and constant vigilance to protect trees like Hyperion from logging and development.  The less intimidatingly tall trees that are my closer neighbors—the California coastal redwoods of the Santa Cruz mountains—are protected by State and County parks, regional open space trusts, and some of the most strict land use policies/local zoning laws in the world.

On one hand this is fantastic.  It means I can drive less than an hour and be among trees that are taller than all of the buildings around me in my day-to-day.  On the other hand, it is one of the reasons why my rent would make your teeth hurt.  My region regularly contends for one of the top 3 most expensive places to live in this country.

You see, nature comes at a big-picture macroeconomic cost. When you have many rules, regulations and norms limiting the area of development to protect wilderness, and other rules limiting the height of buildings so you can see that wilderness, you seriously constrain housing supply.  That’s why not just San Francisco, but every single nature-loving liberal-leaning city has stupid, and rising, cost of living.

That’s why I want my future cities to get their asses off the ground.  Ground has many benefits for plants, but fewer benefits for concrete.  I want my city to minimize it’s footprint and maximize it’s living space up in the air.  I imagine this basic form is a great start.

 

Of course, I want a much bigger structure.  A mere 8 stories over a few square miles is not nearly enough.  I want over a hundred stories over a hundred miles or more.  I want an arcology as tall as Hyperion and as big as the whole San Francisco Bay Area. That’s how I imagine BayArc, my city of 2115.  Get all these humans up off the land, and they can live over it.  They can live over the water.  There can be more hills for people to live atop.  And below, below there can be open space.  There can be trees.  There can be farms and orchards again on this land that used to be called the “valley of heart’s delight” for the fruit it grew.

And, I want that structure to not only be as tall as Hyperion, and have trees growing below it, but to have trees growing atop it.  That is another kind of challenge.

The green tower of Milan is instructive: a few dozen feet of elevation makes trees grow really differently, makes some trees more appropriate than others, calls our attention to tree lines.  This is an ecological challenge.  Bosco Verticale in Milan had to account for which trees grew better at every storey of their gorgeous residential towers, completed last year circa the World Expo.

I do not know what trees would grow in BayArc.  I imagine there would be niches for all the California natives: redwoods and many oaks and madrone and bay laurel.  There are likely other useful trees that would fill out the altitudes and niches and ecosystem services BayArc would require.  I’ll dream of them tonight.