Zero carbon concrete street furniture?

Concrete street furniture can be fun.  However, even if they add relatively small amounts of thermal mass and carbon foot print to the cityscape, it could be avoided.

Is low or zero carbon expensive?
These small and humble elements could be an excellent exploration ground for the use of zero carbon concrete and contribute to the current early stages of scaling zero carbon cement. And as the excellent Hannah Ritchie argues (she writes ‘Sustainability by numbers’ on Substack), the ‘green premium’ for using zero carbon cement is not very large when factoring in aggregate, fabrication, labour, etc. She estimates that if zero carbon cement were say 75% pricier than the (very) high carbon variant, it would only increase the construction costs of a house by 1%.  So a 1% cost increase could make a serious dent into world construction emissions, once this cement is scaled and available of course.

What are the disadvantages of low carbon cement?
It is not yet extensively commercially available except as precast products. As far as the sourcing of the zero carbon cement itself, it would either have to be through willing development partners – I would try to get Brimstone onboard – or initially aim for transition low carbon products with 85% reduced carbon emissions, such as EcoCrete by Heidelberg Materials.

To reduce thermal mass: reduce material amounts, use light colours and add plants.