Mario Carpo

Publication History:

“What Architects Need to Know About Carbon.” Metropolis, New York (electronic publication, February 2020: https://www.metropolismag.com/sustainability/what-architects-should-know-about-carbon/)

The text posted here may be different from the published version. Please only cite from copy on the publisher’s website

The latest issue of the architectural journal Log, published in New York by the Anyone Corporation, offers an overview of contemporary design positions on energy and environmental matters, and suggests a new conceptual framework for architecture, a discipline that is only beginning to grapple with the constraints imposed by global warming and climate change. This is a brief primer to this burgeoning field of design theory—largely derived by Log 47: Overcoming Carbon Form (but I alone am to blame for some additions of my own devising).

What is Carbon Form? 

According to Elisa Iturbe, who guest-edited the issue, “carbon form” is every human-made object, cultural technology, idea, or ideology, based on, or advocating, the combustion of fossil fuels (coal, petroleum, natural gas).

What’s the difference between burning wood, which humans have always done, and burning fossil fuels, which only started with the industrial revolution? 

Chemically, not much—all combustion produces heat, carbon dioxide, and often toxic fumes. But fossil fuels are in a sense concentrated timber, so when they burn they release much more heat, and much more carbon dioxide than plain timber. The energy derived from fossil fuels has powered the industrial revolution, and the carbon dioxide thus released has since accumulated in the atmosphere, causing rising temperatures on earth and in the air (due to a greenhouse effect first described in 1896; rising temperatures started to be called “global warming” in the late 1990s and global warming, in turn, was named by the United Nations as the main cause of climate change in 2001).
The industrial revolution and its belated architectural avatar, 20th-century Modernism, were both based on the assumption that energy and raw materials would be forever cheap and available in unlimited amounts. Since the early 1970s (in fact, since the discovery of the second law of thermodynamics around 1850) we have known that there are theoretical and practical limits to economic growth, but global warming now imposes more drastic and urgent measures to cap, stop, or even reverse industrial expansion. Unfortunately, many architects and planners practicing today still like to think that climate change is primarily someone else’s business, and even when paying lip service to environmental matters and regulations, or embracing green trends, they keep designing, producing, or otherwise extolling “carbon forms”.

What’s wrong with carbon?

With carbon as such, nothing. Carbohydrates, for example, like pasta and pizza, are not part of the problem (in fact, a carb diet instead of a meat diet could be part of the solution). The culprit is carbon dioxide, the chemical result of all combustion, or oxidation (including cellular respiration and animal breathing).  So when we say “carbon form,” or “carbon neutral,” we actually mean “carbon dioxide form,” “carbon dioxide neutral,” etc. Photosynthesis, as it happens in nature, is in a sense the reversal of fire. Plants absorb carbon dioxide from the air and convert it into carbohydrates, i.e. into organic life; some of these carbohydrates are then further converted into timber. As plants absorb more carbon dioxide through photosynthesis than they produce from their own organic processes, timber is frozen carbon dioxide (a “carbon sink”): therefore, the more timber we use in buildings, the more carbon dioxide we sequester (assuming that that timber does not rot or burn, and so long as all timber we chop down is grown for that purpose).

Is there anything else architects can do, beyond using timber instead of steel, bricks, or concrete (and taking care of HVAC, which we started doing long ago)?

For a start, the entire “carbon balance” of a building should be taken into account—that means calculating the “carbon footprint” of all its components for their entire life cycle, including their transportation to site, and their eventual disposal; crucially, that also means calculating the carbon footprint of all foreseeable patterns of use for each building (including the transportation of people and goods). Thus, experts today often distinguish “operational” from “embodied” carbon loads (or energy, or emissions). But that is evidently not enough.  As some of the authors in this issue of Log eloquently argue, in order to stop global warming we should stop building; in order to reverse global warming, we should stop using, or start demolishing, most of the existing buildings and infrastructure. None of the featured authors spell out the inevitable corollary of this plan: as we can neither feed nor house the population of the industrialized world using pre-industrial technologies alone, this solution would require eliminating at least part of the current world population. (How do we do that? History offers plenty of unsavory examples. Population degrowth could be planned by central governments, through demographic control, or worse; other, even more drastic solutions could be left to the invisible hand of the markets, which at some point will need global war to fix a few problems inherent in unbridled capitalism, including global warming).

Are there alternatives to such maximalist or “collapsologist” projects?

Technical change comes to mind. Technologies based on electronic transmission have a smaller carbon footprint than the technologies of mechanical transportation they replace. Example: a Skype call can replace air travel—even train travel and sailing boat travel; an article I can read online replaces a subway ride to the library; a movie I can stream at home eliminates travel to a movie theater, and even the need to build one; etc. Likewise, technologies based on digital mass-customization have a smaller carbon footprint than technologies based on mechanical mass-production. Example: in the old industrial system the cheapest way to make, say, a teapot, was to build the biggest possible factory in one place, and use that one factory to mass-produce as many identical teapots as possible, to maximize economies of scale. In that system, raw materials and finished products alike had to be transported across the globe, regardless of distances, costs, and national borders. Digital fabrication does not work that way. When using digital design and manufacturing tools, economies of scale are theoretically irrelevant: making more of the same will not make anything cheaper; the smallest local shop will have roughly the same production costs as the biggest centralized factory. To go back to the same example, a 3D-printed teapot made by a digital artisan at the corner of the street, when needed, where needed, as needed, from local clay and networked data, should be (in theory) as cheap as the cheapest industrially made teapot imported from another continent. The electrical power needed to run machines and computers can be locally generated too, and from renewable sources. Renewable electrical energy (solar, wind, hydro) has no marginal carbon footprint, and no marginal costs (i.e., excepting the start-up costs and carbon footprint of the machinery and installation).

In other words, renewable electrical power is almost unlimited, ubiquitous, carbon-free, and cost-free (disclaimer: thermodynamic considerations still apply). In turn, carbon-free, cost-free electricity could power an almost unlimited number of robots—which, in turn, have no digestion hence they have an even smaller marginal carbon footprint than the human workers they replace. And by the way, by most metrics, renewables are already cheaper than energy derived from fossil fuels.

Technical solutions in general are not popular these days, but the are a few remarkable exceptions. See for example, in Log 47, Elisa Iturbe’s interview to Rhiana Gunn-Wright, one of the architects of the Green New Deal.  Sustainable growth is possible, if technology is driven by the pursuit of social justice.  But this requires technical expertise and political mediation, and most people today—particularly in the design professions—are averse to a political use of technology.  As in the 1930s, many might simply opt for the usual, nefarious shortcut: violence and war.