"Eliminate carbon dioxide, and plants would shrivel and die. So would lake and ocean phytoplankton, grasses, kelp and other water plants. After that, animal and human life would disappear. Even reducing CO2 levels too much – sending them back to pre-industrial levels, for example – would have terrible consequences for crops, other plants, animals and humans.":
https://www.masterresource.org/carbon-dioxide/co2-gas-of-lif...
Cement is the source of 8% of the world's CO2 emissions (2018)
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Re: Cement is the source of 8% of the world's CO2 emissions (2018)
#72Earlier quoted context omitted.
That was my biggest take away from the Biosphere documentary, as it was the concrete used in it's construction that eventually led to the abundance of CO2 and lack of O2 in that closed system. We'll clearly have to use something else for building moon bases.
Why would a moonbase need to be a closed system? What would stop it scrubbing the CO2 and venting it in to space?
Eventually, you could convert all O2 to CO2 and be left with nothing?
Re: Cement is the source of 8% of the world's CO2 emissions (2018)
#73Would living in tents reduce CO2 emissions? Is that preferable?
How often do you replace your tent? Does it come from china?
Re: Cement is the source of 8% of the world's CO2 emissions (2018)
#74The article doesn't mention one alternative: CLT (cross laminated timber) as a building material for houses and flats. See https://www.bbc.com/future/article/20190717-climate-change-w... for example. Using CLT (and passive house principles) can reduce the total CO2 emmissions of a house by 90% in its total life span. The wood in CLT stores carbon and the passive house principles reduces energy needs.
Yes. And better than that using this at scale is going to require massively scaling up wood production (i.e. forestry). This too will help with capturing a lot of co2 in the soil. A lot of countries would end up restoring farm land to production forests and probably end up using sustainable practices for this. For those unfamiliar with CLT, this is a high tech building material suitable for making e.g. sky scrapers o…
What are the long term health effects of the chemicals used in the production of CLT, on the residents of the houses?
Re: Cement is the source of 8% of the world's CO2 emissions (2018)
#75"Eliminate carbon dioxide, and plants would shrivel and die. So would lake and ocean phytoplankton, grasses, kelp and other water plants. After that, animal and human life would disappear. Even reducing CO2 levels too much – sending them back to pre-industrial levels, for example – would have terrible consequences for crops, other plants, animals and humans.": https://www.masterresource.org/carbon-dioxide/co2-gas-of-…
The minimum necessary CO2 level for plant life is about 100 ppm. That is a quarter of current levels. No plant life, no animal life, no life on the continents. Only a few chemeotroph bacteria survive.
The long term geobiological trend is for C02 to decrease through absorption by weathering rocks and burial of biogenic limestone in subduction zones. C02 was thought to be as much 50% early Earth. Then a percent or two in early Phanerozoic 400 million years ago. And natural about .025% in the current ice age.
Re: Cement is the source of 8% of the world's CO2 emissions (2018)
#76Smells like an new opportunity to tax something while blaming it on climate change.
Re: Cement is the source of 8% of the world's CO2 emissions (2018)
#77The largest issue with concrete is that we misuse it. As a building material it has great thermal mass ( aiding temperature stability ) and longevity. But all too often buildings are poorly designed for renovation, and hence end up being torn down after a couple of decades. A small fraction of the useful lifetime of the structure. Any building using concrete for a structure should be aiming to last at least 100 years…
Do we want 100 year old buildings? I don't think we can predict the needs of building even 20 years into the future. City layout could change drastically. Monumental buildings should last a long time, but not every structure. The alternative is to build from wood whenever possible, and capture extra cabon in building material. This increases market need for wood and therefore forestation.
My house is at least 200 year old and have been inhabited by 4-5 families. Although I must admit that it is thermally very bad, its perfectly livable.
Now the thing is that I like old houses.
So, just pay a nice marketing team to make sure people love old houses (after all, we have marketing team that can sell poison such as cigarettes or carbon dioxide).
Or, as you said, just build with something easier to handle such as wood (provided you recycle it, else it'll go back to biomass, releasing its CO2 again)
Re: Cement is the source of 8% of the world's CO2 emissions (2018)
#78The largest issue with concrete is that we misuse it. As a building material it has great thermal mass ( aiding temperature stability ) and longevity. But all too often buildings are poorly designed for renovation, and hence end up being torn down after a couple of decades. A small fraction of the useful lifetime of the structure. Any building using concrete for a structure should be aiming to last at least 100 years…
In Finland there is effort to capture carbon from industrial emissions and eventually from the air. Pulp mills are very promising.
Turning the cons of concrete into pros (carbon-cured concrete) https://www.vttresearch.com/en/news-and-ideas/turning-cons-c...
>carbon-cured concrete: in carbon curing, concrete is cured with gaseous carbon dioxide, from the plastic phase forward. The curing of concrete with pressurized carbon dioxide generates not only the ordinary reaction products of cement but also carbonate-based reaction products. Consequently, the process binds carbon dioxide, and it is even possible to make the final product carbon negative if ordinary cement is replaced with alternative binders with a low carbon footprint.
The Carbon Reuse Economy: Transforming CO2 from a pollutant into a resource https://cris.vtt.fi/en/publications/the-carbon-reuse-economy...
Re: Cement is the source of 8% of the world's CO2 emissions (2018)
#79The largest issue with concrete is that we misuse it. As a building material it has great thermal mass ( aiding temperature stability ) and longevity. But all too often buildings are poorly designed for renovation, and hence end up being torn down after a couple of decades. A small fraction of the useful lifetime of the structure. Any building using concrete for a structure should be aiming to last at least 100 years…
I don't think we want 100yr old buildings (except for history like a famous temple etc.). Certainly in my country old buildings are not designed in any environmentally conscious way. They aren't energy saving. They aren't in any way designed to be naturally cooler in the summer or hotter in the winter. They aren't designed for the changing needs of society which went from walking and horses 100 years ago whatever it is today. Why would I think a building made today is going to be a good building for the needs of people 100yrs from now?
Re: Cement is the source of 8% of the world's CO2 emissions (2018)
#80The largest issue with concrete is that we misuse it. As a building material it has great thermal mass ( aiding temperature stability ) and longevity. But all too often buildings are poorly designed for renovation, and hence end up being torn down after a couple of decades. A small fraction of the useful lifetime of the structure. Any building using concrete for a structure should be aiming to last at least 100 years…
Do we want 100 year old buildings? I don't think we can predict the needs of building even 20 years into the future. City layout could change drastically. Monumental buildings should last a long time, but not every structure. The alternative is to build from wood whenever possible, and capture extra cabon in building material. This increases market need for wood and therefore forestation.
> Do we want 100 year old buildings?
At least a fifth of the UKs housing stock is over a century old, so the answer to that question is yes, if they're built properly...