Jun 22·edited Jun 22Liked by Arielle Samuelson

I highly recommend contacting Dr. Kimberly Kurtis at the Georgia Institute of Technology to discuss the evolution and future of low-emission concrete.

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Thank you for this--I truly had no idea.

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Great fun deep-dive on cement in all its ramifications, from "clinker" to Jay-Z.

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Jun 22Liked by Arielle Samuelson

It's not completely my focus, but I'm pretty sure that cement making is one of the few places where carbon capture and sequestration makes sense, since much of the CO2 does not come from combustion but from other materials.

This recent blog adds some other alternatives, and plenty of architects are trying to substitute other materials.


It also has a link to the cement industry's emissions reductions plans which show 35% or 40% of total CO2 reductions on a "path to zero" from CCS, with the rest from other tech, but apparently CCS can be a bit less if all the other options are employed.

I live downstream from Aspen, and locals have put up with craziness from the 0.1% for decades, but the escalating amount of construction consumption and waste and private jet use is starting to get on some folks' nerves.

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Thank you very much for writing about this topic. The architect of this project is Tadao Ando, who is a “starchitect” but unfortunately doesn’t consider carbon in his projects which are usually made mainly from concrete. Lloyd Alter writes about carbon in the architecture and construction industry on his Substack at Carbon Upfront. Also, a building standard called Passive House, or Passivhaus, is a great solution for architecture and construction because it can drastically reduce energy consumption (by roughly 90% compared to standard building code). Since buildings can consume up 30% of global resources, this can be an excellent starting point to reducing carbon.

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Great article! I wanted to mention though that not all foundations are concrete. Residential construction at least has other options.

Permanent Wood Foundations are a time tested concrete free alternative. There are also more of them out there than people realize. I work with some local Habitat for Humanity affiliates that are building with them as we speak. Those foundations are on-grade PWFs that get called a "slabless slab". The homes contain no cement at all.

Another less common, but lower carbon alternative to concrete is metal helical piers. These are getting some use now, though I have no direct experience with them.

"The New Carbon Architecture" by Bruce King is an excellent primer on how we can be using our buildings to actually fix carbon rather than emit it. A quick read, highly recommended!

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CLT, or cross-laminated timber, is a potentially excellent replacement construction material for concrete. Structurally as strong, yet is essentially large-scale plywood, and made from trees which sequester carbon rather than emit carbon.

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This article about it includes a photo with the caption: The modern mansion utilized more than 7,645 cubic yards of environmentally friendly pervious concrete to create. Good grief.


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Thank you for spotlighting this. The cement/concrete thing was by far the most interesting thing I learned in the Project Drawdown class I took about 4 years ago.

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Perfect. Missed that. It’s central to why the the title of the article is misleading. It hit a nerve in the blame game.

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Honestly with regards to the cement CO2 problem I really don't see any other solution than CCS, at least if we are talking about net-zero concrete at the projected scale global society is and will be using it.

I think the engineering and safety standards for regular concrete are so high, and well known after over a century of study, that any alternative is going to have to go through such a rigorous safety testing environment that it is one we simply don't have time for.

And I don't like thinking zero sum, but maybe this is an area where less consideration of alternatives and just focusing on CCS here, is the most valuable.

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Wait. Who’s responsible for the emissions during construction? In fact, Bey and J have extended the life of the house rather than contribute to more immediate emissions associated with building a new house. Found in Wmag. “Beyoncé’s new home was originally commissioned by modern art power-collectors Bill and Maria Bell (Bill is the son of the creators of The Young and the Restless and The Bold and the Beautiful). It took 15 years to complete, and its construction required 7,645 cubic yards of concrete just for the home alone (that doesn’t even include the driveway). “ I am not taking away the important research in this post, but we need to make sure we present carbon emissions concerns in the context of practices that impact embodied carbon, emissions and sequestration. One might thank Bey and J for not building a brand new house of any kind.

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I knew concrete is climate unfriendly but I also wonder how much rebar was used. Being so close the the San Andreas fault leads me to suspect quite a lot of rebar would have helped prevent inhabitants from being crushed to death in the event of a substantial earthquake. I wonder if the Malibu local government has any building codes and if it does then if they take earthquakes into account.

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So glad you’re covering concrete, and with your trademark humor and smarts. Not only is the production of cement a climate nightmare, so is the sand that’s a critical component of the concrete mix. Check out this episode of 99% Invisible: https://99percentinvisible.org/episode/built-on-sand/ You’ll never look at a beach the same way again.

While it’s true that buying a “used” house is better than building new, I imagine that this one uses beaucoup energy, given it’s size and all that glass. Which equates to an ongoing climate impact. Even when it’s empty.

There is hope for the building industry. The New Buildings Institute is leading the way in quantifying the carbon cost of buildings. https://newbuildings.org/code_policy/embodied-carbon/ And there are others. We can only do better in the future if we know what our impacts are now.

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Generally well researched. A bit heavy handed on the negative side of Portland cement concrete (should have identified the proper name at least once). A bit light on Beonce. However, the hole in the foot item was confusing the details on temperature in the kiln.

I think you might have consultedhttps://www.cement.org/cement-concrete/how-cement-is-made for some of your details.

"The cement kiln heats all the ingredients to about 2,700 degrees Fahrenheit in huge cylindrical steel rotary kilns lined with special firebrick. Kilns are frequently as much as 12 feet in diameter—large enough to accommodate an automobile and longer in many instances than the height of a 40-story building. The large kilns are mounted with the axis inclined slightly from the horizontal."

This converts to about 1480 C.

I didn't notice the PCA point of view, which is a bit more nuanced--https://www.cement.org/sustainability

PCA includes added details on the energy requirements to make Portland cement, and the direction the industry desires to go.

It is fair to say that the world be we know and live in now would not exist without Portland cement. A without petroleum products in general. These are immense challenges to meet and overcome. Anger is only a minor part of the path to solution.

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For me, this story highlights how crappy the estimates of GHG output by different industries are.

The global concrete industry is extremely concentrated, with just a few companies having massive market share. My understanding is that a single concrete company generates close to the 7% of global GHG output you describe. The industry total would be higher still.

A publicly available source of information demonstrating the low quality of industry estimates comes from the US fertilizer industry. 50% of fertilizer used in the US and other industrialized countries comes from methane. In this study (https://online.ucpress.edu/elementa/article/doi/10.1525/elementa.358/112487/Estimation-of-methane-emissions-from-the-U-S), the authors took actual measurements of the methane leaking from 6 US fertilizer plants (about 25% of the total number of plants) and from those measurements, extrapolated to the whole industry. They show the EPA estimates to be off by an order of magnitude (10X larger than estimated using EPA’s crude estimation techniques).

Instead of emitting 0.2 Gg CH4/yr as the U.S. EPA’s Facility Level Information on Greenhouse Gas Tools (FLIGHT) would have it, the researchers’ estimates based on in situ measurements are for 29 (±18) Gg CH4/yr.

I seem to recall that EPA estimates that all US industry taken together generates around the same GHG equivalent as this study estimates for just the fertilizer industry.

Why does this matter? We have very limited time to address the problem of GHG pollution destroying our climate. If we don’t really know the full scale of the problem or where the most GHG pollution comes from, we could well be wasting our precious limited time on less meaningful parts of the problem.

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