
Cement Produces More Pollution Than All the Trucks in the World - pseudolus
https://www.bloomberg.com/news/articles/2019-06-23/green-cement-struggles-to-expand-market-as-pollution-focus-grows
======
patrickk
One alternative to traditional concrete is autoclaved aerated concrete[1], a
70 year old material that's more eco friendly. Some of the advantages are
mentioned in this video[2]. I'm guessing higher upfront cost means it's not
competitive with traditional concrete.

[1]
[https://en.wikipedia.org/wiki/Autoclaved_aerated_concrete](https://en.wikipedia.org/wiki/Autoclaved_aerated_concrete)

[2]
[https://www.youtube.com/watch?v=FS3BTDBMt7I](https://www.youtube.com/watch?v=FS3BTDBMt7I)

~~~
jacques_chester
A core topic of the article is that there a number of less carbon-intensive
means of producing concrete, but all of them are more expensive. As it is
basically a commodity market, price sensitivity among buyers is intense. It's
an example of where carbon trading or carbon pricing would be able to shift
the market's current selection.

~~~
pmoriarty
Papercrete[1] is an interesting material. It's a mix of (usually recycled)
paper and concrete, so clearly using it wouldn't get rid of all of the
pollution caused by concrete production, but it would help. It also can't be
used as a concrete substitute in every situation, but it has some interesting
properties like being a much better insulator than concrete, and being of very
low cost.

[1] -
[https://en.wikipedia.org/wiki/Papercrete](https://en.wikipedia.org/wiki/Papercrete)

------
martincollignon
Interesting to see more and more climate related posts on HN. Posted this a
couple of times already, but I'd encourage everyone to check this paper[0]
that recently came out ("Tackling Climate Change with Machine Learning").

Among one of the initiatives mentioned is a startup called Tomorrow [1] that
integrates with services (Uber, Instacart, etc) to calculate your personal CO2
emissions. They need help to get more of these integrations and more CO2
models. Consider giving a hand to them or other projects like this one [2].

[0] [https://arxiv.org/abs/1906.05433](https://arxiv.org/abs/1906.05433)

[1] [https://www.tmrow.com/](https://www.tmrow.com/)

[2] [https://openclimatefix.github.io/](https://openclimatefix.github.io/)

------
Tuna-Fish
However, concrete very slowly absorbs the CO2 back from the air, becoming
limestone.

I know this takes very long for thick structures, on the order of centuries.
Does anyone have a good idea of just how long?

Anyway, if a cement plant starts capturing the CO2 released during production
and disposing of it somewhere other than the atmosphere, it would become a CO2
sink as the cement would slowly consume CO2 as it cures.

~~~
the8472
Calcining will release CO2 from the lime _plus_ CO2 from the fuel to heat it.
Only the former will be reabsorbed over time.

And if the timescales are long enough the absorbtion still wouldn't bring you
to net-zero because during the time the CO2 in the atmosphere it participated
in positive feedback loops.

------
maxk42
So nobody is going to mention that cement itself sequesters carbon dioxide?

[https://www.cement.org/for-concrete-books-
learning/concrete-...](https://www.cement.org/for-concrete-books-
learning/concrete-technology/concrete-design-production/concrete-as-a-carbon-
sink)

[http://theconversation.com/eco-cement-the-cheapest-carbon-
se...](http://theconversation.com/eco-cement-the-cheapest-carbon-
sequestration-on-the-planet-10978)

[https://www.sciencedirect.com/book/9780081024447/carbon-
diox...](https://www.sciencedirect.com/book/9780081024447/carbon-dioxide-
sequestration-in-cementitious-construction-materials)

~~~
Arn_Thor
As best as I can tell, two of your links talk about development of cement that
could sequester CO2 (just like the article we're commenting on mentions too).
The problem is that it's too expensive relative to regular cement. One of your
links concludes "we don't know" how much CO2 regular cement sequesters.

------
noja
Is there an ordered list of what produces most pollution? What's at the top?
Is there an easy way to answer the question "I just did environmentally bad
thing X, now what can I do to offset that?"

~~~
inapis
Yes. Fossil fuels for power generation, followed by transportation and
industry [1]

> Is there an easy way to answer the question "I just did environmentally bad
> thing X, now what can I do to offset that?"

Little bit but to seriously make an impact you might have to look for
alternative sources of powering your life. But nevertheless every single bit
helps. This climate change conundrum cannot be fixed without the entire planet
committing to it.

[1] [https://ourworldindata.org/co2-and-other-greenhouse-gas-
emis...](https://ourworldindata.org/co2-and-other-greenhouse-gas-
emissions#co2-emissions-by-sector)

~~~
nabla9
The list you provide is missing some man made sources of CO2 and methane. It's
just CO2 emissions from fuel combustion.

Meat production is almost as much as transportation, roughly 17%.

~~~
sampo
> Meat production is almost as much as transportation, roughly 17%.

That 17% includes all transportation related to meat production. If meat was
replaced by plant-based foods, not all of that transportation could be
eliminated.

~~~
nikehat
Livestock consume far more feed grains (mostly corn) than they produce food on
their own [1]. The transportation costs to feed them are greater than the
transportation costs would be if we were to feed humans on plant based foods,
so transportation would actually be reduced if we lowered the amount of animal
products we consume.

[1] [http://news.cornell.edu/stories/1997/08/us-could-
feed-800-mi...](http://news.cornell.edu/stories/1997/08/us-could-
feed-800-million-people-grain-livestock-eat)

~~~
sampo
That is a US-specific article. In the US, animal agriculture contributes about
2.8% of US total CO2eq emissions, whereas US transportation sector contributes
26%.

[https://skepticalscience.com/animal-agriculture-meat-
global-...](https://skepticalscience.com/animal-agriculture-meat-global-
warming.htm)

~~~
nikehat
Not sure what your point is. I never said emissions related to animal
agriculture outweigh total transportation emissions. What I said was reducing
meat consumption would lower transportation emissions associated with food.

------
alexandercrohde
Instead of us throwing a million comments at this, I think a carbon tax would
let the market sort it out.

There doesn't need to be an X vs Y debate.

------
cmutel
In our research, we see that the easy alternatives are being used almost to
capacity already, making future improvement difficult. For example, there is
basically no unused fly ash in Europe, and it is sometimes imported from as
far away as India. Similarly, burning wastes for "free" heat is also limited
by the availability of waste (residues from chemicals industry, tires, etc).
This is particularly true in areas where waste incineration is the norm -
plants built to service a certain volume of waste are struggling as wastes
volumes decline due to diversion to recycling. Consumer waste has a rather
high water content, so wastes with high energetic content help the
incineration run better. This is why e.g. paper or plastic is sometimes burned
instead of being recycled.

~~~
the8472
What about silicate based cements that are supposed to be carbon-negative
(they were in the news a few years ago)? Those come from mined minerals and
thus not limited by available waste products.

Would carbon taxes help evening cost differences?

------
thatfrenchguy
One good thing the US and Canada does is to not use cement for houses ! It is
somewhat negated by the terrible insulation in most homes in the US (and the
fact that homes tend to last less long I guess). Does anyone have any data on
how much gets emitted for house construction depending on the material ?

~~~
galangalalgol
The us doesn't use concrete for residential walls (very often) but that is
actually quite good from an insulation perspective. Hollow wood framed walls
have a lot better r factor than solid concrete. We do have solid concrete
foundations.

Edit: hollow walls filled with fiberglass to keep the air still

~~~
taneq
With hollow walls you can just use blow-in wool or cellulose insulation to
make it even better. Can't really improve concrete without gluing polystyrene
to it.

Hmm, could you just mix expanded polystyrene balls in to cement to make a
high-R composite that's still strong enough to be structural?

~~~
shereadsthenews
Usually concrete walls have a foam core. Solid concrete is only about R0.5/in,
about half as good as wood.

Even so, insulated cavities are totally obsolete. Exterior foam is far
superior.

~~~
taneq
Wow, really? Interesting, the one's I'm familiar with (used in tilt-up
construction) are just solid concrete (maybe plus some rebar).

Totally with you on exterior foam though, you want the insulation outside of
the thermal mass if at all possible.

~~~
dillonmckay
Check out ICF:

[https://en.m.wikipedia.org/wiki/Insulating_concrete_form](https://en.m.wikipedia.org/wiki/Insulating_concrete_form)

There may be some copyright shenanigans w/ that page.

There have also been successfully constructed in-ground pools using this
material, but appears to be controversial to traditional pool-builders.

------
voyager2
[https://en.wikipedia.org/wiki/Compressed_earth_block](https://en.wikipedia.org/wiki/Compressed_earth_block)

Concrete can be replaced in part through the use of CEB/CSEB and/or rammed
earth.

~~~
ggcdn
This is maybe okay for single family homes in arid regions, but not practical
for denser forms of housing. Which we should be striving for, if we're worried
about reducing pollution

~~~
voyager2
CEB has been used for centuries in Britain. Arid is obviously not a factor.
It's also been used for multi-story buildings. I'm not sure how dense housing
reduces pollution though. Some of the least polluting housing in the world is
rural, e.g. the Amish.

edit: I should have said "earthen" construction has been used in Britain. Cob
rather than CEB.

~~~
ggcdn
It's not possible for us all to live like the Amish. Dense housing (as opposed
to sprawling single family homes) is more efficient to build, heat, provide
utilities, and provide services around. It seems pretty self evident to me
that urban living can produce less pollution over its lifecyle.

------
l0b0
Not disputing these findings, but there are so many "X is worse than Y"
reports these days I feel like reporters are playing rock/paper/scissors, each
one with _different_ rocks, papers and scissors.

------
SomeOldThrow
[https://en.m.wikipedia.org/wiki/Hempcrete](https://en.m.wikipedia.org/wiki/Hempcrete)

------
aaronbrethorst
Mass timber (also sometimes referred to as CLT) has the potential to replace
cement for the construction of many types of buildings.

Mass timber has an extra benefit too: since trees scrub CO2 from the
atmosphere, growing trees for construction ends up sequestering significant
amounts of CO2.

There's a lot of work to be done around sustainable forestry practices, along
with the process of actually harvesting the associated wood, but I think this
is a pretty cool option.

Here's an article that provides some context on mass timber, along with some
of the outstanding questions: [https://e360.yale.edu/features/as-mass-timber-
takes-off-how-...](https://e360.yale.edu/features/as-mass-timber-takes-off-
how-green-is-this-new-building-material)

------
seanwilson
> “There are cement products with lower environmental impact, but they usually
> cost more than the normal ones”

Is anywhere in the world starting to charge for the externalised costs that
allow the less sustainable option to be cheaper like in this example? What are
the issues with this solution?

------
mattfrommars
I was involve in trying to prove
[https://en.wikipedia.org/wiki/Autoclaved_aerated_concrete](https://en.wikipedia.org/wiki/Autoclaved_aerated_concrete)
a viable alternate to concrete and red brick frequently used in household
development. The only part I was unable to secure was seed capital. Does
anyone know of program which invest in green/climate fighting `hard` start
ups? Love to get in touch with them and revive my project.

~~~
Gibbon1
I think AAC is an increasingly common building material outside the US. I
think it's being regulated out of existence in Europe because because AAC only
has moderate R values it can't meet passive house rules. R value of 15 or so
vs the 30 or more required by passive house. Which is insane. Passive house
assumes the house is going to be heated with fuel oil or nat gas it's whole
life. And it's obvious that isn't going to be case over newer houses 100-200
year working life.

Dirty secret about solar and wind is the supply isn't constrained like oil and
nat gas. So designing houses around energy scarcity is 'dumb'. And building
houses to use nat gas/fuel oil even dumber.

------
peteradio
Grading everything on one thing like CO2 pollution seems far too simplistic. I
don't think you can get away with that approach, somehow we need a more
holistic plan. Should we stop using Cement? What happens if we take that
approach, do the alternatives that fill the gap actually further the ultimate
goal, what even is the ultimate goal?

~~~
pjkundert
Absolutely. Reducing the plume of soot belching over the North Pole,
blackening our ice fields would be a good, useful and achievable start.

Or is that not Politically Correct pollution?

------
ThomPete
It also saves more lives, and make modern civilization possible. You always
have to look at both the pros and the cons.

------
the-dude
Produces more CO2.

~~~
taneq
Yeah, we're gonna need to start being a little clearer about what we mean by
"pollution", or comparisons become meaningless. Is a ton of CO2 better or
worse than 100g of mercury?

------
midnitewarrior
Telling a lie then saying 3 Hail Marys means you are forgiven for the lie, it
doesn't fix the lie.

As such, planting a tree to be forgiven for going on a flight that burns
carbon-laden jet fuel doesn't fix what you did.

Fossil fuels are excess carbon atoms sequestered safely deep inside the Earth.
Unless you can find a way to put them back there, there's no fixing the
situation. Planting a tree does capture carbon. However, when it dies and
rots, all the carbon gets re-released over time back into the atmosphere. If
you burn that wood, it happens much more quickly.

The only way to fix this problem is to stop using fossil fuels. There is no
politically viable way for this to happen. The only way this is happening is
if the planet gets depopulated of humans rapidly.

~~~
bin0
> The only way this is happening is if the planet gets depopulated of humans
> rapidly.

Please don't tell me you're one of those "earth would be better of were we all
dead" people. I can't stand that kind of post-modernist, nihilistic garbage.
I'm not mister optimist, but still, that's way too far.

Also, that kind of rhetoric is going to end up being a justification for some
one very evil doing some thing very bad.

> The only way to fix this problem is to stop using fossil fuels. There is no
> politically viable way for this to happen.

Eeh, wrong. The fact that we're not there yet doesn't mean we can't get there.
At some point, pulling energy out of thin air will end up cheaper than doing
expensive drilling operations.

Post-modernists are the philosophical equivalent of the kid who gets mad when
he loses at Monopoly, flips the board, and walks away.

~~~
icxa
If these people really believed that overpopulation was the problem, then why
don't they start depopulating with themselves? __*

It sounds terrible I know, but it serves to demonstrate the hypocrisy of the
stance. Like George Carlin said,

"I’m tired of these self-righteous environmentalists, these white, bourgeois
liberals who think the only thing wrong with this country is that there aren’t
enough bicycle paths. People trying to make the world safe for Volvos.
Besides, environmentalists don’t give a shit about the planet. Not in the
abstract they don’t. You know what they’re interested in? A clean place to
live. Their own habitat. They’re worried that some day in the future they
might be personally inconvenienced. Narrow, unenlightened self-interest
doesn’t impress me."

* note: don't actually do this if you believe this wretched, damned worldview, go seek help, I don't really want anyone to off themselves because they think it "helps the world"

~~~
pbhjpbhj
Suppose we have enough people and resources to support the current population,
but not enough to support 20% more at the same level of luxury ... you don't
think we should bother to try and keep the population at the level where
everyone can benefit?

~~~
dorgo
I think we should improve our tools/planing/everything to support 20% more of
us at a higher level of luxury..

~~~
pbhjpbhj
And we'll do it with our infinite levels of resources and energy, yay! /s

------
boyadjian
High birth rate is the scourge of our time. Cement pollution is just a
consequence.

------
graycat
There's a video documentary on YouTube, complete with starting with PM
Thatcher and her concerns about the coal miners union and the Mideast oil
kingdoms and through the present with sun spots, etc. There is a lot from MIT
prof Lindzen. The 800 year lag in the graph Gore put up is made clear. The
Medieval Warm period, the Little Ice Age, and the cooling from 1940 to 1970
are also clear.

The URL is

[https://www.youtube.com/watch?v=52Mx0_8YEtg](https://www.youtube.com/watch?v=52Mx0_8YEtg)

Now where does this documentary go wrong?

I will mention one place: Their little cartoon has sun light hitting the
surface of the earth, _reflecting_ , and then heating the atmosphere. Well, it
mostly isn't just _reflection_. Instead, the sunlight gets absorbed by the
surface, the surface warms, and then the surface radiates, as in a Planck
_gray_ body in the infrared. CO2 absorbs, and warms, in three narrow bands out
in the infrared, on band for each of bending, stretching, and twisting of the
molecule. CO2 won't absorb visible light -- e.g., exhale and see if you can
see the CO2 or its shadow from absorbing visible light! And, as in the
cartoon, the visible light already traveled through the whole atmosphere to
the ground without being absorbed so that any _reflected_ light should just
continue until it hits a cloud or just escapes into outer space. So, the main
point is the Planck black body effect that in effect converts the visible
light CO2 won't absorb to infrared light CO2 can absorb. But, as Lindzen
explains, that all has to be a tiny effect, _small potatoes_.

Just as a question, does anyone have figures on tons per year of (i) CO2 from
volcanoes and (ii) human activities?

For another, does anyone have (i) the number of tons of CO2 in the atmosphere
and (ii) the number of tons of CO2 released into the atmosphere by human
activities in, say, a year?

For one more, if the temperature of the top, say, 1000 feet, of all the oceans
warmed by 1 F, how much CO2, in tons, would be released -- warmer water
absorbs less CO2?

Last, what was the average temperature of the oceans (i) just before the
Little Ice Age, (ii) at the end of the Little Ice Age (say, at the end of the
Maunder Minimum and the return of usual sun spot activity), (iii) in year
1900, and (iv) now?

~~~
kaybe
You can find a lot of figures in the IPCC reports.

[https://www.ipcc.ch/working-group/wg1/](https://www.ipcc.ch/working-
group/wg1/)

[https://www.ipcc.ch/report/ar5/wg1/](https://www.ipcc.ch/report/ar5/wg1/)

------
diveanon
The worst thing you can do for the environment is have children, but that's
not changing.

Cement, fossil fuels, deforestation, livestock etc are all symptoms of
overpopulation and our inability to establish homeostasis anymore.

I don't see a solution to environmental decay into a negative feedback loop
that wipes us out without some form of population control.

It isn't pretty, but we are running out of time and sitting around waiting for
tech to save us isn't a viable strategy.

------
djsumdog
What about all the other forms of pollution? This article focuses entirely on
CO2. Do these newer cement alternatives have fewer waste products too, or
more? Are those waste products recyclable?

CO2 feels like just a weird focus, compared to the toxic lakes of sludge in
China near manufacturing hubs, the massive drifts of plastic in our oceans,
the coal ash pools at all our coal plants, the nuclear waste still kept at all
our nuclear plans, and all the other waste and pollution we product. Reducing
one at the expense of another may not always end up in a good net result.

This article totally ignores all the other factors of pollution and doesn't
take an fully balanced look at all the waste produced in these materials.

Ultimate to reduce harm to our environment we need to produce less entirely.
That does mean fewer buildings, cell phones, new things, etc. But no one
really talks about that.

~~~
hokkos
It's not a weird focus, there is few more urgent topic than co2, because there
is so much useful chemical reaction producing it that humans need or enjoy,
and we don't see any reduction in those emissions.

------
yters
In terms of greenhouse gasses, the biggest polluter is probably the ocean
pumping all the water vapor into the atmosphere. Water vapor has by far the
greatest greenhouse effect, accounting for about 65-85% of the greenhouse
effect vs human generated CO2 that directly contributes 0.12%.

[http://www.realclimate.org/index.php/archives/2006/01/calcul...](http://www.realclimate.org/index.php/archives/2006/01/calculating-
the-greenhouse-effect/)

If we really want to change things, we'll have to get rid of the ocean.

Seriously, though, I'd like to see some real numbers that if we completely
eliminated human CO2 emissions, what is the actual difference that would make?
What does that say about the significance of practically achievable reduction
in human CO2 emissions? What amount of CO2 would we have to recapture to make
a difference? What amount can we practically capture?

I am getting the impression that these numbers might paint the CO2 dilemma as
completely unsolvable. Sure, maybe in some way every little bit helps, but
maybe it helps like using a squirt gun to put out a volcano. It'd be nice to
know just how relevant our efforts would actually be if everyone unified and
did the absolute best we could do, even so far as drastic population reduction
or even complete elimination of human beings. Would even such Thanos like
measures do anything, or would that just be bringing a second squirt gun to
the volcano?

