for - sustainable building - lime is better than cement - it faciliates reuse

for - sustainable building - cement mortar is the worst thing for re-using bricks

for - cement - process inefficiency

process inefficiency - cement (see below)

• The world over we crush rocks (like gabbro) into gravel. - We dig up and pulverise limestone.
• In gas powered factories we burn the limestone to make cement.
• We dig up a lot of sharp sand.
• At state-of-the-art batching plants we mix them with water to make liquid concrete.
• With sophisticated algorithms and just in time management principals
  • a fleet of wagons distributes it to building sites. - Meanwhile we’ve
  • laid out steel falsework and
  • timber formwork.
  • sprayed on releasing agent and
  • laid rebar on spacer blocks.
  • pour on the concrete
  • vibrate, level and float it and then wait.
• A week later we strip away the formwork;
  • after 28 days we remove the falsework.
  • Hey presto! Stone again!
  • In two months we’ve turned
    • a lump of 230N stone into
    • a lump of 40N concrete.

for - stats - carbon footprint of stone, steel, concrete

stats - carbon footprint - stone, steel , concrete - ( see below)

• The Inventory of Embodied Carbon and Energy 2019 says carbon footprint of the following building materials are:
  • ‘General stone’ - 0.079kg carbon per kg .
  • Concrete - 0.15kg carbon per kg and
  • Steel - 2.8kg carbon per kg.

Überblick zu den Möglichkeiten, die Zement- und Stahlindustrie zu dekarbonisieren. Grundsätzlich ist beides möglich, dazu muss sich aber die Regierungs- und Subventionspolitik radikal ändern und Kapital in den globalen Süden fließen. Es is möglich, sogar Wolkenkratzer so zu bauen, dass sie CO2 binden. Heute wird pro Kopf der Weltbevölkerung im Jahr eine halbe Tonne CO2-intensiver Zement produziert.

https://www.youtube.com/watch?v=b-Wp0sLpnMY

PVA Glue used in bookbinding, but isn't inexpensive.

• Tacky glue - okay
• rubber cement - not great
• elmer's glue - not great, tears esp. for 2 layers
• Mod podge - pulls nicely and strong
• mod podge hard shell - cracks, not great
• PVA Glue - the best of the group

Recommendations in order: PVA, Tacky Glue, Mod Podge (regular)

Brush on top edge and do two coats. Don't get it down between sheets.

There are researchers looking at the amount of fossil fuel energy required for the transition. One research group is MIT: https://climate.mit.edu/ask-mit/does-concrete-needed-build-renewable-energy-negate-good

Other researchers have estimated fossil fuel budgets that need to be reserved for building the initial renewable energy production infrastructure for the transition.

Research is nonlinear. A recent breakthrough might circularize cement industry:

‘If Cambridge Electric Cement lives up to the promise it has shown in early laboratory trials, it could be a turning point in the journey to a safe future climate. Combining steel and cement recycling in a single process powered by renewable electricity, this could secure the supply of the basic materials of construction to support the infrastructure of a zero emissions world and to enable economic development where it is most needed.’ http://www.eng.cam.ac.uk/news/cambridge-engineers-invent-world-s-first-zero-emissions-cement

Will this conference debate rebound effects of efficiency? If not, it will not have the desirable net effect.

My linked In comments were:

Alessandro Blasi, will this conference address the rebound effect? In particular, Brockway et al. have done a 2021 meta-analysis of 33 research papers on rebound effects of energy efficiency efforts and conclude:

"...economy-wide rebound effects may erode more than half of the expected energy savings from improved energy efficiency. We also find that many of the mechanisms driving rebound effects are overlooked by integrated assessment and global energy models. We therefore conclude that global energy scenarios may underestimate the future rate of growth of global energy demand."

https://www.sciencedirect.com/science/article/pii/S1364032121000769?via%3Dihub

Unless psychological and sociological interventions are applied along with energy efficiency to mitigate rebound effects, you will likely and ironically lose huge efficiencies in the entire efficiency intervention itself.

Also, as brought up by other commentators, there is a difference between efficiency and degrowth. Intelligent degrowth may work, especially applied to carbon intensive areas of the economy and can be offset by high growth in low carbon areas of the economy.

Vaclav Smil is pessimistic about a green energy revolution replacing fossil fuels https://www.ft.com/content/71072c77-53b3-4efd-92ae-c92dc02f09ad, which opens up the door to serious consideration of degrowth, not just efficiency improvements. Perhaps the answer is in a combination of all of the above, including targeted degrowth.

Technology moves quickly and unexpectedly. At the time of Smil's book release, there was no low carbon cement. Now there is a promising breakthrough: https://www.cnbc.com/2022/04/28/carbon-free-cement-breakthrough-dcvc-put-55-million-into-brimstone.html

As researchers around the globe work feverishly to make low carbon breakthroughs, there is obviously no guarantee of when they will occur. In that case then, with only a few years to peak, it would seem the lowest risk pathway would be to prioritize the precautionary principle over a gambling pathway (such as relying on Negative Emissions Technology breakthroughs) and perhaps consider along with rebound effect conditioned efficiency improvements also include a strategy of at least trialing a temporary, intentional degrowth of high carbon industries / growth of low carbon industries.