The Guardian’s Concrete Screed – Entirely Missing The Point About CO2

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The Guardian is treating us to an entire week’s worth of stories about how evil concrete is. It paves over the land the bugs live on d’ye see? The bit about us being able to live efficiently on our concrete platforms, thereby leaving more land available for the bugs, rather passes them by.

However, there’s a rather larger lack in their analysis. They insist that concrete manufacture produces CO2 emissions. They’re right there, it does. It’s not entirely obvious that there’s a solution here for the manufacture of concrete is, at a certain level of understanding, the production of CO2 emissions. We’re actively trying to drive the CO2 out of the source materials in our manufacturing of concrete, that’s the point.

So, much for concrete then and the 6% or so of global emissions it causes.

Except we do rather need to ask why are we making the concrete? The answer being that the value of it comes from the absorption of CO2 over the life of the concrete in use. We drive it off to make something we can play with, then once we’ve played we allow it to set. Concrete setting being, again at a certain terribly simplistic level of understanding, allowing CO2 back into the concrete.

That’s something we really should be told, don’t you think?

Concrete: the most destructive material on Earth

Seems a bit de trop doesn’t it? I’d put human idiocy as the most destructive thing upon Earth but if we’re to restrict ourselves to materials I’d suggest study guides in any of the grievance studies.

But:

It also magnifies the extreme weather it shelters us from. Taking in all stages of production, concrete is said to be responsible for up to 8% of the world’s CO2. Among materials, only coal, oil and gas are a greater source of greenhouse gases. Half of concrete’s CO2 emissions are created during the manufacture of clinker, the most-energy intensive part of the cement-making process.

OK, but we really do need to be told the other part of this:

What most people do not realize is that the release of carbon dioxide from calcination in the manufacture of portland cement may also be part of a cyclic process and is partially carbon neutral in smaller timeframes such as decades and may be fully carbon neutral in longer timeframes. It is easy to picture the organic portion of the carbon cycle with respect to plants as previously mentioned; carbon is absorbed through photosynthesis and released through respiration or decomposition. Inorganic forms of solid carbon such as rock are also part of the carbon cycle. Rocks and other minerals are by far the largest sinks of carbon on Earth and they can weather or decompose, either naturally or through anthropogenic processes such as in cement kilns. The carbon dioxide released to the atmosphere is naturally in constant flux with other large sinks, such as the oceans and other surface waters, where it dissolves and through a variety of both organic and inorganic calcareous processes, such as reef formation and precipitation, settles back into the Earth’s crust.

However, concrete can also absorb carbon dioxide and store it in a process commonly referred to as carbonation. This may be viewed simply as an additional, alternative loop of the complex carbon cycle. Carbon dioxide may be absorbed by concrete in its many forms such as buildings, bridges and pavements (Figures 1a, b and c). Concrete does not even necessarily have to be directly exposed to the atmosphere for this process to occur. Underground concrete piping and foundations can absorb CO2 from air in the soil, and underground and underwater applications might absorb dissolved carbon dioxide (carbonates) present in groundwater, freshwater, and salt**ter.

The Guardian. Partial, alarmist and misleading. Who would have thought it, eh?

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Rhoda Klapp
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Rhoda Klapp

When they say 6 or 8 percent of global emissions, they really ought to quantify it in clearer terms. Of MAN-MADE emissions maybe. Of Global, not so much. Nothing like as much. As a part of the (largely unmapped) carbon cycle it’s negligible. And then there’s natural limestone. What do they think that is doing, just sitting there?

Quentin Vole
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Quentin Vole

I was about to say “if only The Guardian understood science”. But then the word science can be replaced with just about any logical concept or fact about the world.

There is science, logic, reason; there is thought verified by experience. And then there is The Guardian. As Edward Abbey (1927-89), would have said.

Jonathan Harston
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Jonathan Harston

It’s what stymied Biosphere 2 – the designers, grounded in the biological sciences rather than construciton engineering, didn’t realise that the concrete in the structure they’d built would absorb CO2, and their monitoring of their “sealed” environment seemed to be losing too much oxygen.

Q46
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Q46

We could always go back to cutting down the forests for building. We are burning them instead of coal after all, because the High Priests have declared wood sacrifice is consistent with the new religion. Many bugs live under ground and are quite happy and safe under concrete: new ones perhaps have evolved. Also the nooks, crannies, in concrete make new and suitable habitats for many bugs too. ‘Environementalists’ do seem to have an incomplete understanding of nature and environment. 0,3% of the atmosphere is CO2 of which 97% is from natural sources. 6% of the rest…pffff. The CO2 obsession… Read more »

PeterBurgess
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PeterBurgess

It is good to challenge conclusions … I have done it all my life. Issues around the carbon cycle are complex and it is difficult to be absolutely certain about anything. My understanding of the carbon cycle is that all the different parts of the cycle operate at very different speeds … and it is the speed of everything we now do as people in an industrialized society that is causing most of the atmospheric carbon concentration that is the modern problem that needs to be addressed. What is most worrying to me is that the amount of warming caused… Read more »